Cinema 4D Training Introducing VRay | Version1

Transcription

Cinema 4D Training Introducing VRay | Version1
The C4D Vault presents
Cinema 4D Training
Introducing VRay | Version1
A short guide to the settings of VRayForC4D
Stuart Lynch
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Project files can be found at
http://www.thec4dvault.com/vrayguide.zip
case sensitive
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TheC4DVault(.com)
TheC4DVault.com was created by Stuart Lynch and provides Cinema 4D training, resources and sample
files for the C4D community. Stuart is a veteran Cinema 4D user with over 10 years of professional experience in the industry and several years providing instructional information to intermediate users.
This first in a series of new short instructional pdf ’s is aimed at providing the user with enough information to digest without becoming overwhelmed. It highlights the backend of VRay and relates the importance of understanding the settings that make VRayForC4D one of the best render engines around.
Over the coming months, TheC4DVault pdf booklets will cover a wide variety of topics, providing a free
and reliable way to learn Cinema 4D.
“I hope you enjoy this first addition and learn a thing or two about VRay in the process. Thanks for reading.”
Stuart Lynch
http://www.project1media.com
Please make a minimal donation to keep the resource alive.
*See Donate section at www.thec4dvault.com
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Chapter 1: Introducing VRay - The Sun and Sky
If you were to search images.google with
the term ‘VRay’, one of the first thing you’ll
notice is the abundant usage of the Physical
Sun/Sky setup.
It’s a practical solution for lighting interiors
and will serve as our first demonstration of
the VRay engine at work.
figure 1.2
In figure 1.2 I’ve created a primitive cube with
2 segments on each side. The geometry has
been edited and 2 simple openings have been
extruded on the most distant polygons.
The editor camera has been positioned in the
center of the screen and I’ve exaggerated the
field of view slightly to include both openings.
figure 1.1
In figure 1.1 we have the Sun light parameters
which allow us to make changes to the Sun’s
intensity and it’s physical properties.
figure 1.3
For this example we’re simply going to activate the Sun/Sky and become familiar with
the lighting it provides for the scene.
To complete this portion of the setup, I’ve
added a simple target light figure 1.3.
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It’s time to turn our C4D shot into a VRay
scene. First activate VRay in the
Render Settings - figure 1.4
figure 1.7
You’ve now successfully activated VRay and
and activated GI.
Feel free to test the render.
figure 1.4
You’ll notice now a new VRay Bridge Option
figure 1.5 has appeared for VRay on the left
hand side
figure 1.8
Now that you’ve witnessed the true power of
VRay, you might want to take it to the next
level.
figure 1.5
Clicking the VRayBridge option will reveal
the many VRay bridge parameters geared
towards the final rendering setup.
Right click the light object in the Object
Manager and scroll down to the VRay tags.
From the list, you’ll want to add a VRayLight
tag. figure 1.8.
Next click on the tab that says
IndirectIllumination figure 1.6
and check the first box that says
GI ON figure 1.7
figure 1.9
The information required to manipulate
VRay lights specifically is now contained in
the VRay light tag for future reference. figure
1.9 You can double click this tag at any time
to retrieve this set of parameters.
figure 1.6
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The VRayLight tag contains a lot of important functionality and we’ll become familiar
with all of the options as we progress.
In figure 1.11 I have checked the boxes Physical
Sun and Physical Sky.
A test render figure 1.12 will now reveal a room
illuminated by the physical qualities of the
sun and sky together.
For now, our intention is change the target
spotlight to become a Sun light with a
PhysicalSky
In the option Light type figure 1.4 Change from
a Spot light to an Infinite light.
Also check Enable shadows
figure 1.12
Focussing on the details of the render, it’s
possible to notice that there’s a slight flaw in
the accuracy of the lighting.
The sunlight that enters the room looks
overexposed, yet the subsequent light falloff is too dramatic and occurs too quickly.
Meaning, the rest of the room is too dark
when compared to the intensity of the sun.
figure 1.10
The light now is as it suggests, an infinite
light and not yet a Sun Light. In order for the
light to become a Sun Light we must click
the Sun Light tag and make a few adjustments
Maybe it’s that the scene needs a fill light or
perhaps we’ve missed the more GI ‘bounces’
option, after all it’s an interior scene.
Not so fast!
The solution in Color Mapping
figure 1.11
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Color mapping
To make a point stick with his students, my college instructor would occasionally use profanity.
So let me say that using Color Mapping in your workflow will often save your ASS!
There are plenty of headaches to come, trust me, but with this simple workflow you’ll avoid blown out
light sources that can make or break a render.
figure 1.13
figure 1.14
It’s a straight forward concept to understand when illustrated with this amazing set of renders.
In figure 1.13 The area light in this simple room appears to give off the correct light intensity and
illuminates the portion of the room closest to camera. But at the source, the light appears ‘nuked’
In figure 1.14 If we dial back the lighting intensity a little, the light at the source appears to have corrected
itself, but at the expense of less light reaching the back of the room.
figure 1.15
In figure 1.15 the light intensity is restored to the brightness of figure 1.13, color mapping is applied and the
light adequately reaches the entire space. Balance is accomplished.
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You can use find this function in VRay settings under Color Mapping. figure 1.16
figure 1.16
By default VRay uses the ‘Color Mapping’ type (menu option Type) Linear Multiply with default Dark and
Bright Multiplier values set to 1
You will notice several other Types in this drop down menu.
Exponential
HSV Exponential
Intesity Exponential
Gamma Correction
Intesity Gamma
Reinhard
The most practical color mapping Type for interior rendering is Exponential mode (or HSV Exponential)
For exterior shots, it is recommended to use Reinhard
The following settings are a general guideline for what these numbers should look like.
FOR INDOOR SHOTS.
FOR OUTDOOR SCENES.
Type: Exponential (some prefer HSV exponential)
Dark Multiplier: 3.6
Brightness Multiplier: 1.8
Gamma: Between 1.8 - 2.2
LinearWorkFlow - Check to ON
Type: Reinhard
Multiplier: 1.5
Burn Value: 0.5
Gamma: Between 1.8 - 2.2
LinearWorkFlow - Check to ON
If you’re not already aware of the implications of using a LWF - See the following PDF
http://www.pixsim.co.uk/downloads/The_Beginners_Explanation_of_Gamma_Correction_and_Linear_Workflow.pdf
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It wouldn’t be fair to offer you this
solution without some idea of what’s
happening behind the scenes. After all, you
did buy the book from a desire to learn.
In figure 1.17 we have the issue where the sunlight is not illuminating the scene correctly.
In figure 1.18 the samples illuminate the shot
correctly and the light intensity is well balanced.
So if we apply the ‘Indoor’ settings from the
guidelines on the previous page, we can draw
comparison to the original Sun/Sky render.
The difference lies in the mode Exponential, this prevents colors from becoming
too burned out and bright. It’ll saturate the
colors as they reach too high of an intensity.
figure 1.17 is
the original without color mapping applied (Gamma 1.0)
figure 1.18 in exponential mode with the guideline values (3.6/1.8/2.0) (Gamma 2.0)
The darkness multiplier value increase to 3.6
indicates that the original output of grey/
blue will have be multiplied by 3.6, giving
rise to the additional light and brightness in
the scene.
The brightness multiplier is increased to 1.8
Which indicates that although the exponential value has reduced overall brightness, it
can still be multiplied to compensate for the
dip you see in figure 1.19.
You can consider it a compromise.
In figure figure 1.19 the brightness multiplier
is being left at its default value of 1.0 and the
sunlight would be too low in its intensity.
figure 1.17
figure 1.18
figure 1.19
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Chapter 2: The test scene
In this chapter we’ll begin with a quick scene and will introduce the Physical Camera.
In VRay it’s important to use as accurate a
measurements as possible.
This basic cube is 500cm x 200cm x 800cm
and represents our small bedroom. figure 2.1
With the camera inside the model, select all
polygons and reverse normals so that they’re
facing inwards. (hotkeys U~R)
figure 2.3
figure 2.1
Selecting two faces as shown below figure 2.4
Use inner extrude (hotkey I) and extrude (hotkey
D) to create two window openings.
In figure 2.2 I’ve added 5 segments to the X
side of the model. Edit the model (hotkey C)
and move the editor camera inside of the
model.
Here you could split the glass geometry for
later (hotkeys U~S) or simply delete the two
polygons.
figure 2.2
figure 2.4
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Returning to the editor view, raise the lowest
portion of the windows up slightly. figure 2.8
Switch to the point tool and from the
attributes manager uncheck ‘Only select Visible Elements’
figure 2.5
In the Top viewport select the polygons that
make up the front window and rear wall.
Drag to the left as in figure 2.6
figure 2.8
Repeat the process for the Right window as
shown in figure 2.7
Select all the polygons on the floor plane and
extrude down slightly to create room for a
thin moulding feature figure 2.9
Select all ceiling polygons, perform a slight
inner extrude and then a regular extrude
upwards. figure 2.10
figure 2.6
figure 2.9
figure 2.7
figure 2.10
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Select the wall polygons in between the windows and extrude. figure 2.11
Don’t be concerned if your shot is nothing
like mine. If your scene has two openings I’ll
forgive you.
Moving on.
figure 2.11
In figure 2.12, extrude the ceiling polygons to
match the moulding extrusion.
figure 2.14 - ‘Test render for illustration purposes only’
figure 2.12
Perform a simple select loop command with
the polygon tool (hotkey U~L) figure 2.13 and
Extrude slightly at 91°
figure 2.13
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‘Roughing out’ the lights
Find a place where you’re happy with the
viewport representation of your scene and
add a regular Camera.
Returning again to the editor view and
ensuring you have you camera selected. Run
your first render. figure 2.16
figure 2.14
figure 2.16
Clearly not enough light entering the room
on this angle. This issue of balance is more
prominent than in my initial examples.
Add a Target Light and position yourself in
the top view, try to find a placement for the
target light where you would like the Sun to
exist. figure 2.15
It’s time to apply Color Mapping to bring the
room to life. figure 2.16
REMINDER
FOR INDOOR SHOTS.
Type: Exponential (some prefer HSV exponential)
Dark Multiplier: 3.6
Brightness Multiplier: 1.8
Gamma: Between 1.8 - 2.2
LinearWorkFlow - Check to ON
figure 2.15
Select VRay as your primary render engine
in RenderSettings and as in the earlier example, check GI on in the IndirectIllumination tab.
Add a VRay Light tag to your Target light,
check enable shadows, change from spot
light to infinite light. In the SunLight tab
activate the Physical sun and Physical Sky.
figure 2.17
A small improvement.
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Bringing the shot to life.
So far we haven’t included any materials in our scene. VRay responds to color change quite dramatically,
as does color in the real world. If we add a tiled wood texture to the floor, the bounced light from the
wood and its color values will have an affect on the scene. Let’s explore further......
From the Material Manager add a new VRay
Advanced Material to the scene. figure 2.18
figure 2.18
Double click the Material ‘Wood’
In the Diffuse Layer - Texture map slot.
Load a wood tile texture figure 2.21
Assign the new VRay Advanced Material to your cube
object in the OM (object
manager). figure 2.19
figure 2.21
In the OM select (click) the wood material
tag. In the Attributes Manager, change the
projection mode from Spherical to Cubic
I’ve named my material ‘base’
Using the texture axis tool and the scale tool
figure 2.22 Scale the wood texture to fit your
scene.
figure 2.19
Create a second VRay Advanced Material
and change the name to ‘wood’
Select all floor polygons and drag the ‘wood’
material over the polygon selection figure 2.20
figure 2.20
figure 2.22
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Running a new test render, notice how the
wooden floor is affecting the lighting in the
rest of the scene. figure 2.23
The presence of more white objects has
changed the dynamic lighting of the scene
once again. figure 2.25
figure 2.23
figure 2.25
Make a few adjustments to your camera position and to the SunLight and try to balance
both lighting direction and composition.
Adding some additional materials with
variations in color (preferably chosen to represent
how you imagine your scene) we’re able to improve
upon the overall feel of the shot. figure 2.26
figure 2.24
figure 2.24
figure 2.26
In this next phase of scene creation, we’ll
start blocking out some objects with simple
geometry to get a better feel for composition.
With all of these geometry additions you
may have noticed that the light in the room
has taken a significant dip in brightness.
On the next page we’ll discuss the Physical
Camera and how to implement photographic
values in order to restore the balance.
Place Cube primitive objects and position
them where the bed, side tables and cabinet
would potentially be.
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Introduction to the Physical camera
The Physical Camera in VRay allows us to reproduce the parameters of a real world camera.
To improve our scene without further adjusting the Color Mapping or the default lighting intensity of the
Sun, we’ll implement the Physical Camera and make use of its features such as ISO and FStop.
It’s good practice to use the Physical camera
for all of your scenes.
From the OM select your scene Camera,
right click and apply a VRay Physical Camera tag from the VRay Bridge Tags submenu.
We’ll look more closely at comparisons in a
later chapter, for now we’re occupied with
increasing the exposure values of our scene
without making any adjustments to light
intensity.
figure 2.27
Click the VRay Physical Camera tag
Under the Tab - Lens parameters.
Scroll down to Film ISO and change the
value from 100 to 400
A test render produces this result figure 2.28
figure 2.27
If you test a new render you would notice
that no significant changes have occurred.
Though the default settings of the VRay
Physical camera provide a similar result,
they differ greatly from a camera that has no
Physical properties.
The proof is in the numbers.
figure 2.28
In the VRay Light tag under the Sun light
parameters you’ll see two separate values.
Intensity multiplier for Phys Cam : 1
Intensity multiplier for Std Cam: 0.037
The sun intensity is divided by exactly 270
to work at the default value of the standard
camera.
figure 2.26 ‘Old result for comparison’
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An increase in Film ISO values from 400 to
1600 figure 2.29 increases the film sensitivity
further and subsequently alters the brightness of the scene.
In figure 2.30 I’ve added a new bed and a some
subtle blurry reflections (refereed to as Glossiness
reflections in VRay) to the wood material.
Although I’ll shortly be introducing more
detailed information on the VRay Advanced
Material, if you want to add this effect to
your current scene, I’ll show you the quick
way.
Changes in F-Stop values can also be made
to compensate for brightness.
Shutter speed can typically be left alone,
although it is an important value when introducing motionblur into your workflow.
Activate a Specular layer in your wood material and input a Glossiness reflection value of
0.8.
figure 2.29
figure 2.31
If you’d like to continue with your scene and
start placing actual geometry or re-working
the blocked out models to become realistic
fixtures in the room. Feel free.
A couple of tweaks later and some stock
models from my collection. figure 2.31
figure 2.32
Few renders looks complete without a little
post work. figure 2.32
figure 2.30
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Chapter 3: Introducing VrayBridge render settings
Quality is very important when we think about final renders, but this shouldn’t always come at the cost
of lengthy render times. Through exploring VRay’s render settings we’ll learn to tweak the parameters in
order to get the best results in an optimal amount of time.
In this section we’ll optimize the VRay Render Settings and then explore the method behind the madness. Open the example bedroom.c4d open from www.thec4dvault.com and lets begin.
figure 3.1
The Light Cache is an approximation of the
global illumination in the scene. figure 3.4
figure 3.2
figure 3.4 ‘The familiar Light Cache calculation’
From the Tab Indirect Illumination (GI)
select ‘01_IR-LC_very very fast’ from the GI
Preset list
At these low settings rendering with Light
Cache as both a first and second bounces
as with figure 3.5 would produce some odd
splotchy results.
IR refers to Irradiance Map
LC refers to Light Cache
Although with the correct values, this technique is equal to Unbiased rendering.
GI Preset 19_LC_LC_PPT_unbiased is set
up to render in this way.
In the Primary and Secondary bounces
you can see the two modes being selected.
With this setup the Light Cache will be calculated first. figure 3.3
figure 3.3
figure 3.5
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After successful completion of Light Caching, the Engine then begins computation the
Irradiance Map.
The more refined the Irradiance map settings
are, the better it is able to assist in rendering
smaller details. This also comes at the cost of
render time.
A simplified explanation of the Irradiance
map is to imagine a point cloud that originates from the Camera and projects outwards into the scene.
Objects such as walls and floors require very
little IR sampling, but a detailed ornament
on a table needs more refined samples to
reach the tight spaces.
In figure 3.6 I’m using a VRay resource
called IMapViewer.exe. With this we’re able
to view the resulting IR map in its raw form.
Providing adequate coverage is much less
of a struggle than it may seem. VRay comes
loaded with presets that provide an excellent
starting point in most cases.
From the camera perspective in the bottom
left corner, it’s quite easy to visualize the job
of the Irradiance map. There are no samples
outside of the Camera view and so we can
conclude, it only samples what it needs to
see.
figure 3.8
The DMC Sampler figure 3.8 is the VRay
control Room. These 4 values basically determine how VRay uses its adaptive sampler,
which I’ll explain later.
figure 3.6
The engine itself uses deterministic Monte
Carlo sampling (DMC), which is a high
quality approximation GI algorithm. The
better the settings, the more reliable and accurate that approximation becomes.
The simple scene below is the resulting figure
3.7 render from the above calculation.
It’s not imperative that we learn exactly how
the backend of VRay works. What’s important is that we understand how these vast
amounts of values will affect our end results.
We’ll need to break them down a little in
order to make sense of them.
figure 3.7
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Anti Aliasing (AA) is another important factor in determining final VRay render quality.
In the tab Indirect Illumination (GI) click
the Irradiance Map arrow to reveal more settings figure 3.11
change the Hemispheric SubD
The Adaptive DMC Anti Aliasing mode figure
3.9 and the DMC sampler figure 3.8 are tied
in very closely, especially when compared
to other Anti Aliasing techniques like the
Adaptive Subdivision sampler
figure 3.11
figure 3.12
For Hemispheric SubDivision enter the
value: 30
For Interpolated samples enter a value of: 10
We can ignore the other settings for now.
figure 3.9
Back to the DMC sampler, add the values
from figure 3.10
figure 3.12
Still in the tab Indirect Illumination (GI)
click the Light Cache arrow figure 3.11
In here we’ll simply be changing the Samples
Ratio from 1/2 to 1/16 figure 3.13
figure 3.10
Adaptive amount will be left alone.
Minimum samples have been reduced from
8 to 4
Noise threshold was in an okay place with
0.01, so we won’t touch that either.
Global Subdivs multiplier is set 0.5, down
from 1.
figure 3.13
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Finally under the Options tab un-check the
Glossy Effects to prevent any blurry reflections from calculating figure 3.14
figure 3.16
If your render happens to look as it does in
figure 3.16, it would be because you haven’t yet
applied Color Mapping. Not mentioning it
this was an intentional test.
We’ve barely scratched the surface of this
new information and I have you dialing in
numbers that probably make no sense to you
whatsoever.
figure 3.14
Now we can run our first preview quality
render at ultra fast speed.
My instructional method is to teach through
example. Once you’re familiarized with the
process it will start to become second nature.
Yet that is only part of the equation.
It is also important to have a basic understanding of why each value works the way it
does.
In this next section we’ll adjust for a final
render a along the way I’ll point out some of
the method behind the madness.
figure 3.15
The result is awful, yet it took only 12 seconds to render at 1280x720.
This very low setting is a perfect place to
start from if you’re blocking out the scene
and need to make quick decisions.
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Creating a higher quality render
Reload the example bedroom.c4d
#5 Color Mapping tab
Attempt this without illustration (please)
Type: Exponential (some prefer HSV exponential)
Dark Multiplier: 3.6
Brightness Multiplier: 1.8
Gamma: Between 1.8 - 2.2
LinearWorkFlow - Check to ON
#1 In the tab Indirect Illumination (GI) select ‘03_IR-LC_medium’ from the GI Preset
list and check the box GI On
#2 In the Irradiance Map sub menu
Min Rate: -3
Max rate: -1
Hemispheric SubDivision: 55
Interpolated samples: 15
#6 Time to render.
Leave every other IR setting alone
#3 In the Light Cache submenu
Un-check Override LC Subdivision
Subdivision: 1000
Scroll down a little to
Reconstruction parameters
figure 3.17
My render time at 1280x720 on a 6 core
I7-980x (running at 4.4ghz)was 1 min 48 seconds.
Un-check Enable LC retrace
#3 In DMC Sampler tab
For a scene with Global illumination that’s
not a bad time.
Adaptive amount: 0.85
Noise threshold: 0.01
Minimum samples 8
Global Subdiv multiplier: 1
But was the result ready to send to a client?
#4 In the Antialiasing tab
Well, aside from the fact that the scene is
pretty bad to begin with, I’d still have to go
with “no”.
Antialiasing type: DMC sampler
Filter on: Check Filter type: Catmull-Rom
Min SubD: 1
Max SubD: 5
There’s artifacting issues in a couple of areas,
too much noise in the wood and black glossy
metal and it needs a little more.
It feels close but it could use a little more to
sell it as final.
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Indirect Illumination - Irradiance map
Tempting as it may appear to ignore this section and rely upon VRay’s preset values, I would recommend
against it. Presets only solve half of the equation, they have no affect on AA or the DMC sampler and
they’re not intended to provide a complete setup for your scene.
Instead see the presets as a good starting point. The Medium quality preset is sufficient for most projects
and only requires a few minor adjustments to bring it up to speed.
When rendering a GI shot in VRay, the
engine requires two solutions to produce accurate GI results. Those are the Primary and
Secondary bounces.
Each of the approximation methods has its
own very specific parameters.
The IR map (IR map - Irradiance map) has many
options for the management of correctly
calculating samples, sample accuracy and detail enhancement. It also has a section used
exclusively for animation,.
In figure 3.18 I’ve turned off secondary bounces
and left the Primary bounces as: Irradiance
map.
The first two parameters you come across are
Min rate and Max rate. These settings relate
to the size of the IR map calculation.
With only one GI engine actively calculating,
a correct GI solution has not been possible.
This is visible as the dark areas in the image.
The Min value “determines the resolution for
the first GI pass”. The Max value determines
the resolution for the last GI pass.
A Max value of 0 would imply that the
resolution of the last GI pass is equal to the
dimension of your scene resolution.
A value of -1 is equal to half the resolution of
the dimensions of your scene resolution.
figure 3.18
So far we’ve used only two of the five
possible GI engines in these slots. The preset
values highlight other combinations, though
the IR and LC is our focus for the time being.
A Min value of :-4
and a
A Max value of: 0,
....would create 5 passes during the caching
process. ( -4, -3. -2, -1 and 0)
As Irradiance map is our primary bounce,
we’ll introduce its settings first.
The Max value 0 is typically not needed for
less complex scenes.
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You could ask why not just have a Min value
of -1 and a Max value of -1? Or a fixed value?
A Hemispheric SubDivision is part of the Irradiance map and is used to determine “the
quality of individual GI samples”. Relating
only to the samples of IR map in this case.
The smaller values in the Min setting (-4 for
example) are important for sampling the bigger
details (walls etc). The larger values in Max (-1
or 0) are for sampling the finer details.
We can look here to improve upon our IR
map caching process. A good starting place
when attempting a final render is around the
50 mark.
You would rarely encounter a need to use a
positive value like 1 in the Max setting. If it
occurs to you to do so, it would be wise to
look elsewhere before concluding that this is
the solution to your rendering woes.
Values upwards of 150 are not unheard of for
problematic renders, though typically you’ll
find that 50-80 is adequate.
Min and Max however, are only part of the
solution.
Interpolated samples refers to the interpolation of the IR map samples. This calculation
look towards the range of existing data and
attempts to refine that process further.
In figure 3.19 the low settings I’ve deliberately
chosen are creating very obvious splotches.
This suggests that are settings are way off the
mark and need to be re-worked.
With this setting - Too high a value is likely
to blur the solution, Too low and the samples
will receive no interpolation.
So we can determine that some Interpolated
samples are necessary.
To compliment the Hemispheric SubDivision, a value of approximately 15-30 is usually always sufficient.
figure 3.19
Refining the IR map settings is how we
prevent splotches and other inaccuracies. It
ensures that this approximation method (our
primary light bounce) will provide enough
samples to assist in a flawless final render.
Note: Over estimating the values can create unnecessarily long render times. Under
estimating causes artifacting. (Not to be
confused with noise)
figure 3.20
Look to the next page for some comparisons.
Page 28
figure 3.21
figure 3.22
figure 3.23
In all of the above examples Hemispheric SubDivision has a value of 50
In figure 3.21 the Interpolated samples value is 1, which at close inspection is too few samples
In figure 3.22 the Interpolated samples value is 100. At this value the samples tend to become blurred.
In figure 3.23 the Interpolated samples value is 20. This is practical amount for most renders.
At this scale it is perhaps difficult to see a huge difference. Also any remaining noise issues you’re seeing
would then be an issue with the DMC sampler and not the IR Map.
There are clearly other settings in the Irradiance map parameters, yet in the interest of not becoming
bogged down with too much input, I’ll only briefly highlight their usage.
To the left of the Min/Max rates lie the Intensity Threshold, Normal Threshold and Distance Threshold.
These settings refer to individual sensitivities to light intensity changes, surface normal changes and
changes in the distance between surfaces. I would leave these values alone and let the provided preset
values guide you until you become more familiar.
There are occasions with objects such as ‘thin blinds’ where adjustments to these settings will benefit your
render.
In the Detail enhancement section are a couple of additional parameters.
This function as the name implies creates additional detail (to small detailed objects, not really useful in a typical scene).
Utilizing this process will force the GI algorithm to compute with Brute Force GI in places that are difficult for the IR map to reach.
When using this function it is often necessary to consider lower overall IR Map settings.
With this option checked we’re dependant upon Detail enhancement to enhance our render, the remaining settings would therefore only need to made be suitable for coverage of the larger objects.
Note: This is because large objects such walls/ceilings typically get adequate coverage from fewer samples.
In my professional career I have used the Detail enhancement function no more than 3 times.
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Indirect Illumination - The Light Cache.
The light cache (once again) is the approximation of global illumination in the scene.
Spot3D.com “The light cache is built by tracing many eye paths from the camera.”
The number of paths traced from the camera
is the square of the subdivision value. 1000²
equals 1 million paths. 2000² is 4 million and
10,000² is 100 million.
The Samples Ratio values are based on the
resolution of your scene. In the case of the
1/1 setting in a scene that’s 1280x720, the
Light Cache would produce 0.9 million
paths.
figure 3.24
I have to admit the first time I saw this
menu, I felt a lot less threatened by it than I
did the Irradiance map options.
In our current IR - LC setup we’re depending
on the Light Cache portion of this solution
to computer the secondary bounces.
figure 3.25
In figure 3.25 I used a Sample ratio of 1/1 at
1280x720, implying 921,600 samples.
The light cache took 28 seconds to compute
In figure 3.24 the Overide LC subdivision box is
checked by default.
The value inside the samples ratio (drop down
menu) and the Subdivision amount (greyed out
box) differ only in mathematical approach.
They both determine how many paths are
traced from the camera.
figure 3.26
Un-checking this box and manually inserting your own value is recommended, especially if the secondary bounces require more
attention.
In figure 3.26 I used a 960 samples in the
Subdivision box. 960² = 921,600 samples. It
should come as no surprise that the calculation took exactly the same amount of time.
Page 30
There are some instances where you’ll need
to go beyond the 1/1 Samples ratio amount
and manually enter Subdivision values.
Though 1/2 is quite sufficient in most cases.
It is imperative to use a higher value during
animation, but rare to exceed 4000.
figure 3.28
With scenes outside of the typical Physical
Sun/Sky setup, where perhaps we’re using an
abundance of light sources . The subdivision
values will benefit from a boost.
Reconstruction parameters.
These parameters control how the light cache
is used in the final rendering, after it has
been calculated.
Prefilter Checked on - Prefilter will be used.
Prefilter is applied once the cache is computer or loaded from disc.
Prefilter samples More prefilter samples
equals a more blurry and less noisy cache.
Filter type. This is for tracing the Light cache
along a camera path and is beneficial for
animation.
figure 3.27
We’ve covered the essentials and I’ll provide
a very brief explanation for the remaining
settings.
Use light cache for glossy rays. If this option
is on, the Light Cache is used to compute
glossy rays as well normal GI rays.
This option can speed up rendering of scene
that have blurry reflections by a significant
amount.
Sample size determines the spacing of
samples in the light cache. (Leave alone for now)
Passes calculates the light cache separately
on each thread of your cpu. (Useful for animation)
Enable LC retrace. This option assists VRay
in preventing light leaks at the expense of
slightly increased calculation time in the IR
Map.
Store direct light. This option stores and
interpolates direct light. This can be useful if
you’re using and IR - LC setup.
Use camera path. This is for tracing the Light
cache along a camera path and is beneficial
for animation.
Retrace threshold. This value can be used in
conjunction with ‘use light cache for glossy
rays’ to help VRay dynamically decide when
and where to use the Light Cache.
Adaptive tracing. Stores additional information about incoming light for each light
sample.
Page 31
The DMC Sampler
Having covered two of the possible GI engines and how their individual passes contribute towards the
quality of the final render, we need to talk about the big guns! The DMC Sampler.
You can think of the DMC sampler as a global quality control.
This group of 4 settings play a very important role in the rest of the workflow.
Looking at an Area light’s parameters (VRay
Light tag), it reveals that the DMC sampler will
be receiving 8 Subdivision samples from this
light source. figure 3.31
The actual amount of samples, is the square
of the subdivision value / 8² subdivisions = 64
figure 3.29
samples
During render time, the DMC sampler is
looking out to your scene for additional
samples.
These rays are computed in such a way that
if the values are too low, they will produce a
noisy result. figure 3.30
figure 3.31
The DMC Sampler can look at a series of
these samples and determine that it has
enough information to not use them all.
This is the role of the Adaptive amount.
figure 3.30
Values from almost every part of the render
engine are coming in through this channel
and being processed here.
Let’s imagine the DMC sampler sees 100
samples for the entire scene. If we chose an
adaptive amount of 0.8, the DMC sampler
will always use 20 of those samples. The
other 80% will be considered internally by
the engine, but not necessarily used.
Whenever you create a light, a blurry reflection, use Depth of field or Motion Blur (to
name a few), you’ve actually been providing the
DMC sampler with more samples and information about the scene.
Control over this function is decided by the
“Early Termination Algorithm”
Page 32
With an Adaptive amount of 1, we hand over
control of all of the samples. (Fully adaptive)
Noise threshold has a value of 0.01
Noise threshold has a value of 0.1
figure 3.34 Noise threshold has a value of 1
figure 3.32
figure 3.33
With an Adaptive amount of 0, All 100
samples will be used without consideration
for the “Early Termination Algorithm”. (Not
A value between 0.01 and 0.004 is a good
range for final renders.
adaptive)
When the Noise Threshold is 1, the DMC
sampler is satisfied that the desired amount
of samples has been met while it’s still producing a very noisy value. This amounts to
an incredibly fast, but noisy render.
In most cases, the default value of 0.85 for
the Adaptive amount is more than sufficient.
At 85% adaptive, this may seem like we’re
leaving too much to chance, giving too much
control to the DMC sampler. But VRay
handles the process very smoothly and it’s
not often necessary to go below 70% (0.7)
The DMC sampler frequently needs more
samples from the external elements that are
difficult to compute.
Noise Threshold.
A metal material that has blurry values
(Glossiness subdivs) such as Brushed steel will
often require more samples to achieve noise
reduction and a quality result.
The Adaptive process communicates directly
with the Noise Threshold amount. This value
determines the amount of noise that is acceptable before it can tun its attention to the
next pixel in the calculation.
Instead of trying to compensate for this in
the DMC sampler, we would simply increase
the Glossiness Subdivs value in the specular
channel of the Vray Advanced material to a
value higher than the default 8. figure 3.35
figure 3.32
figure 3.33
figure 3.35
Similarly, a single Area light that clearly
stands out from the others as having too
much visible noise, would also benefit from
sending more samples to the DMC sampler.
figure 3.34
Page 33
When a single object causes an issue, it’s important to look at it’s individual subdivision
parameters to resolve.
Brute force, Photon maps, or
Spherical harmonics.
It would be a shame to spoil a good balanced
rendering solution and shoot for an overall
increase in quality on account of one problematic object. This wouldn’t be a practical
way to work.
I’ve introduced you to 2 GI engines so far,
the combination of which enables VRay to
process your render.
The IR + LC method is a popular choice and
as an introduction to these practices was
worth highlighting them side by side.
Looking again at figure 3.29 we have 2 settings
remaining to talk about, and both of them at
this point should be easy to comprehend.
Some other useful combinations are highlighted in the presets.
I.e; Lightcache +Bruteforce / IRradiance Map + Bruteforce.
Brute force computes every single shaded
point separately and independently of other
points, (while other approximation methods consider
their neighbor in determining calculation). While
highly accurate this method can also be very
slow.
figure 3.36
Minimum Samples
Min samples equals the minimal amount of
samples that the DMC sampler will compute
before terminating the algorithm.
The subdivision parameter here will also
talk to the DMC sampler in the same way as
discussed earlier.
Note: The default 8 is once again squared
to imply 64. It also intentionally matches
the default number for all subdivision based
parameters.
Global Subdivs multiplier.
Ray depth controls the number of bounces
that will be computed, but is only available
if Brute force is chosen as a secondary GI
engine.
If an overall quality boost is required for
every subdivision based parameter, this is a
good place to dial in some numbers.
Photon maps are occasionally useful for interiors scenes, but this is an older method of
approximation and I typically avoid it.
The default value of 1 implies that every
value will remain the same as the input value
(for example: Glossiness Subdivs: 8)
Spherical harmonics is not yet properly
integrated into VRayForC4D and should be
avoided.
A increase to 1.5 would provide a 150% increase to all of these values. (Increasing the:
Glossiness Subdivs: to 12)
Page 34
Antialiasing
I’m certain you’re all familiar with the practice of using Antialiasing in your scenes.
VRay features 3 types of image samplers (antialiasing methods) and each one differs slightly in approach.
We have the Fixed rate sampler, the Adaptive DMC sampler and the Adaptive Subdivision sampler.
Choosing the right image sampler is determined by the individual scene and there are different considerations for each approach.
figure 3.38
Adaptive DMC sampler figure 3.38
figure 3.37
This sampler takes a variable number of
samples per pixel based on a Min and Max
rate.
Fixed Rate sampler figure 3.37
With this method, the sampler takes a fixed
rate of samples per pixel. The subdivision
value is squared as with other subdivision
parameters. 1² =1 / 2²=4 / etc
It can also use the threshold set in the DMC
sampler to determine if more samples are
needed. (vs manual entry in Threshold amount)
A value of 4 would indicate that 16 samples
had been taken per pixel.
This method is best for scenes that use a lot
of blurry effects and is the preferred image
sampler for DOF and Motion blur effects.
This sampler is simple and predictable in a
broad range of antialiasing tasks, but the nature of a fixed sample can equal slow performance in some cases.
Note: It is rare to have to increase the Min
level higher than 1, other than scenes that are
problematic.
Note: Though not be ignored, I would recommend one of the other two choices based on
my experiences with Fixed rate sampling.
Using Show Samples is a way to preview the
antialiasing setup prior to final render.
Page 35
In the renders from figure 3.40 and figure 3.41 I’ve
zoomed in to 800% to highlight the differences between the Adaptive Subdivision
sampler and the Adaptive DMC sampler.
The render times were seconds apart and
the Min/Max settings identical (with no under
sampling in the Adaptive SubD sampler)
The metallic device has a blurred metal
surface and it’s clear that in this round, the
Adaptive DMC sampler did a better job.
figure 3.39
Adaptive Subdivision sampler figure 3.37
Of the 3 methods, this is the only sampler
that can undersample (take less than 1
sample per pixel).
That’s not to suggest that the DMC sampler
is always the clear winner. The reliability of
Adaptive Subdivision sampler in the absence
of blurry effects can add significant speed
increases to your scenes and should not be
overlooked.
In scenes that don’t rely on blurry effects,
this is the preferred image sampler for both
its speed and reliability. However, in the
presence of these effects it can perform
worse than the DMC sampler.
Experimentation is key.
See below for comparisons.
Antialiasing filter
In VRay as with other render engines,
Antialiasing filters can be applied. These are
methods for sharpening or blurring values
dependant on your needs.
These filters are integrated into the sampling
process and do have an affect on render time.
For example a sharpening filter like Catmullrom and Mitchell-netravali may cost you a
few additional seconds when compared to
blurring filter like Box, Area and Gaussian
and Area.
figure 3.40 - Using the Adaptive Subdivision sampler
Note; These filters are not the same as applying sharpening/blurring filters in post. I would
recommend using one based on your needs at
all times.
figure 3.41 - Using the Adaptive DMC sampler
Page 36
Wrapping up
If you want VRay to create high quality images that don’t take forever to render, then we already have one
thing in common.
To achieve this, I frequently tell my students that the best starting point is from lower/medium quality
presets. From here you’ll be able to discern what part of the render needs your attention the most. Is it
splotches on the walls? Then look to the IR map. Or are the walls fine and it’s some nuisance ornament
with a bump map giving you grief? Then look to it’s material setting, the nearest light source, or better
manage the antialiasing settings.
That may seem like a common sense approach, but if I got a dollar for every time somebody sent me a
scene where they’d randomly entered 0.001 in the Noise Threshold to resolve a simple issue, I’d be rich!
That value may well have fixed the issue, yet they inadvertently made the rest of the scene more complicated than it needed to be. On inspection it’s usually obvious that they were only trying to improve upon
a couple of small problems.
Similarly there’s a list of preset values known as “Universal VRay 1.5 Settings” that people rave about.
You can see the appeal right away, although if you use these settings be open to the possibility of waiting
around for a long time.
It’s my hope that I explained this process with relative clarity. If you do have any unresolved questions the
VRayForC4D manual offers very precise examples of why each setting performs the way it does.
Page 37
Chapter 4: Vray’s materials
Whatever your choice of render engine it’s good practice to have a test scene for trying out materials.
In this chapter we’ll work with such an environment and introduce Vray’s BRDF material system.
Open the scene file test_stage.c4d figure 4.1
figure 4.1
The scene uses three area lights and some
basic geometry, it also renders very quickly
for fast feedback.
figure 4.3
A VRay advanced material has far more
options than a standard C4D mat. The vast
majority of materials you’ll set up in VRay
are relatively straight forward, though with
this much flexibility, there’s a lot of room for
complexity and creativity.
The material editor features many settings
that you’re probably already familiar with
Diffuse (color), Bump, Material weight
(alpha), Luminosity layer (Luminance) and
Specular layers (a mix of C4D’s reflection
and secularity settings), Refraction layer
(transparency)
figure 4.2
Create from the materials manager, a new
VRayBridge - VRay Advanced material
Page 38
Specular layers ‘VrayAdvancedMaterial’
There are 5 Specular layers in VRay, this allows for
the creation of materials with more than one specular
quality, such as varnished woods, car paints and some
plastics.
These layers contain options for both fake specular
highlighting, or in the more physically correct way,
which is to calculate specularity with glossy reflections.
Note: I’ve introduced you several times to the term Glossy. It simple
implies blurry reflections, but is refereed to as ‘reflection glossiness’
in VRay. (See Specular layer parameters)
In a Cinema 4D material, specularity and reflection
are separate entities. In VRay there is the option to use
the Reflection layer, though this is reserved for objects with raw reflection like water and mirrors. It also
doesn’t contain an option to include glossy reflections.
Instead the Specular layer is where you’ll need to
turn for the vast majority of your material reflectivity
needs.
This layer contains options for a vast amount of specular properties such as anisotropic surfaces, blurry metallic surfaces and precise control with fresnel effects
(reflection viewing angle). figure 4.4
figure 4.4
In figure 4.5
Sphere A, the Vray Material is tracing
only the fake specular values.
Sphere B, is tracing both fake specular
and blurry reflections.
Sphere C, is tracing blurry reflections
only.
figure 4.5
Note: In the real world, almost every object contains at least some specularity.
Page 39
For our first material, lets activate a single
Specular Layer and leave everything as default. Apply the material to the sphere object
and perform a quick render test. figure 4.6
figure 4.8
A rendered results should now show a metal
like material that’s been processed with both
fake specularity and glossy reflections. figure
4.9
figure 4.6
In the setting Specular Layer Transparency,
change the amount to 50% and test again.
figure 4.9
At the top of the Specular layer settings is an
option for Specular Type. Change this from
Phong to Ward. The result should now look
like figure 4.10
figure 4.7
The reduction of transparency has allowed
for more of the reflection from this layer to
show. figure 4.7
For the next stage of this material test, add
another Vray advanced material and in the
diffuse channel only, add a blue color. Apply
this new material to the cube object.
Now returning to the first materials Specular
layer. Scroll down to reflection glossiness
and add a value of 0.8. figure 4.8
Page 40
figure 4.10
Each Specular Types computes in a unique
way and provides different results. Blinn and
Ward are good choices for metallic effects
and they also render Anisotropic effects
more accurately.
Back in the Specular layer settings change
the Anisotropy value to 0.5
figure 4.12
Lower the Anisotropy amount back to 0 and
in the Texture map slot below load in the
texture ‘HT_Brushed.png’ from the textures
folder.
Repeat this process as illustrated below in
figure 4.13 - while also checking the invert box
where appropriate.
figure 4.11
The result figure 4.11 is not quite yet a Brushed
metal, but we’re establishing the workflow in
ordered to create one.
For the next step, return to the Diffuse layer
(remaining within the metal material) and reduce
the Diffuse Color - Brightness amount to
20%.
Back to the Specular layer scroll all the way
down to the last few settings and Check the
Use Fresnel box and input 22 for Fresnel IOR
(Index of refraction)
You will now notice that the Specular Layer
Transparency option is no longer available.
This is because we’re using IOR to determine
reflectivity.
In the Specular color at the top, add a Fresnel
shader to the texture map slot. figure 4.12 In the
shader settings, reduce the black to a light
grey. This will prevent the scratched surface
from reaching the sphere’s edges.
figure 4.13
Page 41
We’ve provided VRay with enough information to produce a semi-realistic scratched
metal surface. Work can be done in the
bump map channel to bring out extra details
and a lot of time can be spent tweaking the
values for a perfect result.
You may have noticed that in the Specular
settings I increased the Glossiness SubDivision amount up to 30.
As discussed in the section on VRay’s DMC
sampler, this is an example of where the
material needs to send out more samples in
order to be computed with less noise.
Note: The reason behind the inverted texture
map in the Glossiness reflection is that in reality, the deeper the scratch, the more blurry its
reflectivity would become.
Keep in mind that these sorts of materials
are usually quite render intensive.
The result in figure 4.14 is far from complete,
yet you have a good starting point from
which to experiment further.
figure 4.16 ‘VRay Goldman’
figure 4.14
In both figure 4.16 and figure 4.17 you can see the
vast amount of flexibility available to you in
the Specular layer channel.
Using a similar technique in figure 4.15 to create a Galvanized metal, the differences in
blurry values vs more reflective values are
obvious.
figure 4.15
figure 4.17 “The Weasley’s’
Page 42
The Diffuse layer ‘VrayAdvancedMaterial’
There are two Diffuse layers in the Vray advanced material, these are useful for mixing diffuse (color/texture) effects without resorting to separate materials.
VRay Dirt is also accessible through the Diffuse layer. By applying Ambient occlusion at the material
level this option creates the appearance of dirt on the surface details of an object.
The Diffuse layer Transparency option serves two functions, it is first required to let the underlying layer
show (Diffuse layer 2) and is also required to use the Fast SSS shader option (see page 57)
Open example file scene test_stage2.c4d
Create a new Vray advanced material and apply
to the sphere object.
In Diffuse layer 1 check from the Diffuse options - Use VRayDirt.
The menu layout will now change to the
VRayDirt workflow.
Add a black Color channel to the Occluded
color slot (from the drop down menu)
figure 4.19
In figure 4.18 the result has been intentionally
enhanced to show the overall effect.
Add an 80% white Color channel to the
Occluded color slot (from the drop down
menu)
Any color combination can be used to
achieve the desired look.
In figure 4.20, I’m using a wood texture as the
Unoccluded color and Red for the Occluded
color (Dirt effect).
figure 4.18
Page 43
figure 4.20
Refraction Layer ‘VrayAdvancedMaterial’
The Refraction layer is for the creation of optically transparent materials.
This layer can assist in the creation of standard glass, gems, fluids, complex translucent effects, frosted
glass and much more. It’s parameters contain options for the accurate calculation of Absorption, Blurry
effects, Dispersion and Sub Surface Scattering.
Open example file test_stage_glass.c4d
In the Refraction layer look towards the
Volume Fog parameters and check Enable
Volume.
Create a new Vray advanced material and apply
to the glass object.
Leave the Emission color as default black
and chose a very light orange/yellow for the
Volume Color. Finally increase the amount
to 0.3 and render.
Deactivate the Diffuse layer and activate a
Refraction layer.
Check Specular layer 1 without making any
changes.
Render
figure 4.13
This effect has added absorption properties
to the glass and it now has the appearance of
greater volume.
figure 4.12 - Color enhanced
Without any changes to the default settings,
the Refraction layer provides us with a glass
material with an IOR (index of refraction) of 1.6
Adding a Specular layer to a glass material
is common practice, as glass always includes
some amount of reflectivity.
Page 44
figure 4.14 - Color enhanced
To simulate frosted glass, we would enter
a Glossiness value (0.6 in this example) in the
Refraction layer. As shown in figure 4.15
It is also possible to use the SSS parameters
from the Refraction layer to simulate the
translucent properties of hard wax, honey,
plastics and other surfaces that depend more
on refraction for accurate results.
Variation in the frosted amount can be
achieved by using the Glossiness Texture map
slot.
The example from figure 4.19 uses the following setup. figure 4.18
figure 4.15 - Color enhanced
Note: These effects can add significantly to your render
time and often require additional subdivision values to
render accurately.
The images below contain different examples
of Glossiness effects in the Refraction layer.
figure 4.18
figure 4.16 ‘Visa’ product shot
figure 4.19
Note; To speed up the SSS calculation check
‘Environment fog’ in the SSS parameters. This
stores the light directly in the volume.
figure 4.17 ‘Go Beyond’
Page 45
Sub Surface Scattering ‘VrayAdvancedMaterial’ and ‘VRayFastSSS2 Material’
SSS calculated as part of the refraction layer (as shown on page 45) is an accurate representation of a real
world translucent effect. While it can produce stunning results, it can also be notoriously slow to render.
A much faster approach is to use a VRayFastSSS2 material. The parameters of which are available as an
extension of the standard VRay Advanced material and as a standalone material called the VRayFastSSS2
material.
It’s also possible to cheat translucent effects using the Vray2Sided material. (which we’ll cover on page 48)
The majority of your translucent material needs should be met by the Fast SSS option.
Open example file test_stage_candle.c4d
The rendered result is now noticeably different. figure 4.22
In this scene I’ve simply added a VRayFastSSS material to the cylinder shape, made
a couple of adjustment to color and added a
texture map.
The original Simple mode approximated
translucency from the surface lighting alone.
The Raytraced-Refractive mode traces the
refraction amount based on the provided
IOR.
The result figure 4.20 shows a subtle hint of
translucency.
figure 4.22
Also notice that when VRay is computing
Fast SSS, it’s also adding an additional dark
pass that appears to isolate the translucent
effects.
figure 4.20
In the VRayFastSSS material settings, scroll
down to options and change the Single Scatter parameter from to Simple to Raytracedrefractive. figure 4.21
figure 4.21
Page 46
This is a special pass called the Illumination
map. It can be controlled in the prepass rate
which is set to -1 by default. For higher res
images, a value of 0 is occasionally needed.
Change the Single Scatter parameter from to
Simple to Raytraced-Solid. figure 4.21
This time we’ll use the SSS layer in the VRay
Advanced material to make a semi accurate
portrayal of a marble floor.
The Raytraced-Solid mode will calculate/estimate the Volume inside the object.
Open example file test_stage_marble.c4d
The scene is setup with a marble texture map
and contains only a Diffuse layer.
figure 4.25
The material is starting to look a little better,
but it’s missing glossy reflections and a bump
map.
Activate a Specular Layer , check Use Fresnel
and input a value of 1.6 for the Fresnel IOR
amount. Next, input a Reflection Glossiness
value of .095
figure 4.23
In the Diffuse Layer change the Diffuse
Layer Transparency to 40%. This will allow
underlying effects such as the SSS layer to
mix with the Diffuse Layer at the inputted
value.
Activate Bump and copy the Diffuse Layer
texture into this channel.
At 100% transparency, this Diffuse layer
would no longer render at all.
With no real bump information, you can
increase the value to 3. Though this is not a
practical approach for most materials.
Activate the SSS Layer and try to match the
three shades of green from figure 4.24
The result is far from perfect, but suffice to
say it created the desired affect. figure 4.25
figure 4.24
figure 4.26
Page 47
VRay2Sided Material
Standalone material
Making a ‘lamp shade’ with the bulb obscured behind a layer of fabric (as in figure 4.27) used to be a difficult task to accomplish. Fully opaque materials simply weren’t designed to transmit light through their
surface in this way. Adding Diffuse layer transparency (or alpha in C4D) didn’t help matters either, as a
percentage of the light would simply pass through the volume.
The VRay2Sided material solves this old limitation by allowing us to have a ‘diffuser’ in VRay.
A diffuser softens light as it passes through a surface, essentially making it what we call translucent.
This material was created to address the need for thin translucent objects like paper, leaves, fabrics, diffusers etc, but its application can be much more experimental.
In figure 4.27 ‘the lamp shade’ object highlights an example of how this material was intended to work.
Illumination from within the object passes through the material via translucency and displays the result
on the front facing normals.
The VRay2Sided material is controlled by two standard diffuse materials (VRayAdvanced material) for the
front/back facing normals and a Translucency color to determine how much of the effect should come
through.
The VRay2Sided material in figure 4.28 features reflective properties on its front side. A separate object with
a colored pattern light has been placed within the dragon model (via the Luminosity layer) and the result
creates a glowing translucent effect. This behavior looks closer to a refractive SSS solution, but is actually
cheated as the light is emitted from the inside only. Of course cheating in 3D is never a bad thing.
In figure 4.29 I’m using the same approach but on a much bigger scale. This time I’ve placed uniquely colored light objects within each skyscraper. The Luminosity layer casts its rays outwards and are intended
to fake the lighting that would have otherwise come from a traditional lighting solution. This was a test
scene, but also a very practical solution for visualizing cities at a distance.
figure 4.27
figure 4.28
Page 48
figure 4.29
Open example file scene 2_sided_user.c4d
The light has now penetrated the object as
determined by the parameters in the VRay2Sided material.
This simple setup has an area light, a thin
plane object, a couple of props and currently
no materials. figure 4.30
Leaving the front and back side options of
the VRay2Sided material free of supporting
materials was a deliberate move. It illustrates
that in the absence of a material channel,
the VRay2Sided material will use a standard
grey diffuse VRayAdvanced material by
default.
Additional control is provided by the Translucency color setting. By default it is set
to 50% grey which would allow an equal
amount of the front and back to show (dependent upon illumination values).
figure 4.30
If we the render the shot directly, you’ll see
that the plane object is obscuring the light.
To let more of the Back side material show
through, push the color closer to white. To
retain more of the Front side material, bring
it closer to black.
figure 4.31
You can also use color or a Translucency
texture for experimenting with different
translucent effects.
In the example file scene 2_sided_spherelamp.c4d
you’ll find the following example figure 4.33
and other experiments from my collection.
figure 4.31
Add a VRay2Sided material and apply it to
the plane without any additional changes,
and it will now render a simple diffuser.
figure 4.32
figure 4.33
Note: In order for the Front side material to show at
all, it must be illuminated from the front. It’s a common mistake to light only from the rear and expect
the front side to show.
figure 4.32
Page 49
In this short tutorial, I’ll guide you through
the workflow needed to make the fake SSS
effect used on the Dragon figure 4.28 (on Page 48)
Create a new VRayAdvanced material and
name it ‘Outside’
In Diffuse Layer 1 check Use VRayDirt
Open example file 2_sided_buddha.c4d
Add dark blue for the Occluded color via a
color channel. (See page 43 for help)
Add a light blue for the Unoccluded color via
a color channel. (See page 43 for help)
Finally add Specular layer 1 and make no additional changes.
Next, create a VRay2Sided material and add
the material called ‘Outside’ to the front side
material option of the VRay2Sided material.
figure 4.34
The scene figure 4.34 has a the Buddha figure
and three primitive objects tucked neatly
inside his body.
figure 4.36
Create a VRayAdvanced material and add
a Luminosity layer. Apply a blue Luminosity color, leave at 100% for brightness and
add a value of 10 in the second box labeled
Amount
In Luminosity Layer parameters check
Compensate exposure.
figure 4.36
Finally apply the VRay2Sided material
to the ‘Buddha’ figure and Render. figure 4.37
Note: We’ll be covering Luminosity on the next page.
This backlit fake SSS effect has countless uses
and of course, it looks kinda cool!
figure 4.35
Name this material ‘backlight’ and apply it to
the Null object called ‘Internal’ We now have an internal lighting solution
for the Buddha figure.
figure 4.37
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VRayBlendMaterial
Layering shader - Standalone
The VRayBlendMaterial allows you to stack materials - It works in almost exactly the same way as manually stacking them in the object manager, but allows for better management in some cases.
The process starts off with a base layer such a brick map for example, then additional materials are applied as a coat material, this could be useful for peeling paint of a layer of broken concrete.
Various mapping techniques that have some Material weight (alpha) or Diffuse Layer transparency are
useful in determining to what degree the underlying material is seen.
Below are some examples of materials that have been layered with this technique.
In figure 4.38 an underlying rock material is coated with a slightly translucent coating of snow.
In figure 4.39 glass is affected by a fiery layer and covered with a dusting of sand.
In figure 4.28 an organic rock is coated with a glow based effect based off a vertex map selection.
All very straight forward, but with amazing amounts of potential.
figure 4.38
figure 4.39
figure 4.40
Note: These files are all available in the VrayBlendMaterial folder.
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VRayDisplaceMaterial
The VRayDisplaceMaterial allows the usage of Displacement maps in VRay.
It’s possible to mix this material with a standard VRayAdvancedMaterial by stacking it to the right of the
standard material and choosing ‘Mix textures’ from the texture tag. Let’s quickly explore.
The following example uses the Displacement type: 3D Mapping, which is suited to procedural effects.
In the VRayDisplaceMaterial’s texture path,
add a noise channel from the drop down
menu. Click the noise channel and change
the type to ‘Cel noise’, finally increase the
Global scale value to 250%.
Open example file displacement_user.c4d
In the VRayDisplaceMaterial’s parameters
change the amount to 10cm and check the
box Keep contunity. Render. figure 4.40
figure 4.38
Create a standard VRayAdvanced material
and apply it to the cube.
Create a VRayDisplaceMaterial and also
apply to the cube object (after the first material)
figure 4.40
In figure 4.41 I’ve copied the ‘Cel noise’ to the
VRayAdvancedMaterial’s diffuse channel,
created a couple of layers with some noise
variation and have used VRayDirt (page 43)
Select the VRayDisplaceMaterial tag from
the object manager and check Mix Textures
figure 4.39
Select VrayDisplacement
material.
See file displacement_example .c4d
Use Cubic projection (for both)
Check Mix textures
figure 4.39
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figure 4.40
The Displacement type: 2D Mapping, is used when an image based displacement map is available.
With this workflow, you can maintain a low polygon count and depend on the displacement map to give
the appearance of millions of polygons at a sub polygon level.
In examples figure 4.31 - figure 4.32 the rendered
results shows that although the original
model only had 68,000 polygons, they’ve
been effectively turned to 3.4 million polygons with a displacement map.
Parameters.
The amount value (in both the 3D and 2D options)
control the maximum height of the displacement map.
The shift value specifies a constant amount
that the polygons will be shifted relative to
their normal position.
While Use default parameters is checked, the
resolution for 3D displacement is controlled
via the VRayBridge settings under Displacement.
figure 4.31 ‘Octopus’
The default amount can be set too high for
certain tasks and should be experimented
with for optimal results.
For more in depth features relating to your
displacement needs, please refer to the VRay
manual.
figure 4.42 (zoomed in)
Note: It’s still possible to add a VRayDisplacement Tag from the object manager, although
this is the old workflow and only remains
available for Legacy reasons (to support older
files).
figure 4.43 (zoomed in)
figure 4.33 -is
the 16 bit tif image used to create
the displacement.
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Luminosity Layer ‘VrayAdvancedMaterial’
The Luminosity layer (from the standard VRayAdvancedMaterial) provides light via self illumination.
You can use self-illuminated materials on objects to represent lights that don’t need an actual light source.
An example would be the LCD display on the front of a DVD player, or the backlight for a PDA device.
In VRay, the Luminosity layer also has an option to turn the effect from a standard self illuminated material into a full fledged light source via the Direct Illumination option. Let’s take a look.
Open example file self_illumination.c4d
To make the luminosity brightness adapt
to the physical values of the camera check
Compensate exposure. figure 4.46
The render figure 4.44 has 2 self illuminated
objects and a white Environment light.
Note: This is easier than guessing a new intensity
amount each time we make a change in exposure via
the Physical camera parameters.
Using the luminosity layer in this manner
does not provide adequate shadow density to
be considered a viable lighting solution.
figure 4.46
Check the box Direct Illumination.
This turns the material from a self illuminated source to a physical light source.
Enter an Intensity value of 200 for Direct Illumination parameters.
figure 4.44 (8 second render)
If you add a Physical Camera tag to the available camera, there’s a drastic dip in exposure.
Also in the Environment tag from the Vraybridge settings, increase the Background Environment brightness to 50 to compensate.
figure 4.45
figure 4.45
Page 54
figure 4.47 (Zoomed in)
When the Direct illumination option is
checked the material now features lighting properties almost identical to those of a
VRay Area light.
In figure 4.49 the IR Map was responsible
for the light source. A full render reveals a
slightly softer result when compared to the
more grainy direct sampling method.
The Luminosity color channel and texture
map slots remain effective for colorization of
the light source, but the other channels such
a diffuse and specular would be no longer
available.
The result of the render should now look like
it does in figure 4.48
figure 4.49 (22 second render)
Direct illumination does not work with selection tags, instead the system will manually
override and use standard self illumination
properties.
In the case of a single object with geometry
you wish to use for light (i.e a lamp and bulb as
one object), it is necessary to double click the
selection tag (or manually select the polygons) and
separate the geometry via the split command. Cinema 4D lacks a split and delete
function, so you would also be required to
remove the remaining geometry from the
original object.
figure 4.48 (40 second render)
An increase in Subdivision amount from the
Direct illumination parameters can eliminate
any unwanted noise. This process is sending
samples to the DMC sampler as discussed on
page 32.
The Direct illumination method is sending
out light from all of its surface normals and
can be quite slow to compute, however to
speed things up it’s possible to check Store
with irradiance map and have the light
source compute during the IR Map cache
process.
This Direct illumination method can be
highly beneficial to your workflow, but it
is my recommendation to use it sparingly
and only in situations where a physical light
source cannot accomplish the same task.
Using this approach requires a slightly longer
waiting time during IR map creation, but
shorter overall render time. It also comes at a
cost of a slightly decreased shadow density.
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Chapter 5: Vray lights
VRay lights are dependant on scale, when designing a shot with realism in mind it’s important to respect
the process and work roughly at the real world size of the object in question. Does this always involve
getting out a calculator and pre-planning? No, but the closer you are, the more likely your lights are to
behave as expected.
Vray lights also have physical parameters for accurate measurement of light.
Lighting actual scenes isn’t a topic we’ll be discussing at length in this short book, but we’ll cover the basics and get you up and running with a few small example scenes.
A standard C4D light with shadow parameters enabled will provide VRay with enough
information to render with a with the standard Omni light option.
Accomplishing this wasn’t a simple case of
turning on Area lights, if you note in figure 5.04
that the Default (image) intensity had to be
cranked all the way up to 200.
The result is an underwhelming effect that’s
typical of Omni lights when compared to the
shadow density of an Area light. figure 5.01
figure 5.03 (from example file VrayStudioOmni.c4d )
figure 5.01 (from example file VrayStudioOmni.c4d )
Adding a VRayLight tag to the pair of lights
and turning the default Omni light to Area
light, a few tweaks later things are starting to
look up. figure 5.02
figure 5.02 (from example file VrayStudioArea.c4d )
figure 5.04 (from example file VrayStudioOmni.c4d )
The reason for this is because we’re still using Cinema 4D’s units, which really don’t
represent any real world values. Instead if
we switch the Intensity units to Radiance
(W/m/m/sr), we get a much more accurate
representation of their actual brightness. In
this case, the area lights are 100 watts.
Note: Always remember to ‘enable shadows’
when working with VRayLights. (This parameter
can be found in the VRay Light - Common tab.)
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In the VRay manual...
Quote from “http://vrayc4d.com/manuals/vrayforc4dmanual/common-tab” - VrayC4D Group. All right reserved.
(c) 2008-2010
“Radiant power (W) - total emitted visible light power measured in watts. When using this setting, the intensity of the
light does not depend on its size. Keep in mind that this is
not the same as the electric power consumed by a light bulb
for example. A typical 100W light bulb only emits between
2 and 3 watts as visible light.
figure 5.06 (from example file watt_the_hell.c4d )
Increasing the size of the light figure 5.06, the
Radiance (W/m²/sr) value remains at 20
but the Radiant power (W) value has now
increased to 41.7
Radiance (W/m²/sr) - visible light surface power measured
in watts per square meter per steradian. When this setting is
used, the intensity of the light depends on its size.”
....the units are explained in a common sense
way.
Notice also that with the size change comes
a dramatic shift in shadow density. This is a
real world phenomenon of course and quite
easy to understand why this would happen.
Larger area lights typically require more
samples to render accurately.
In the previous scene, the illumination
strength for the light is heavily compensated
by the exposure settings of physical camera.
Without the physical camera in place, the
scene would have been massively overbright.
In example file watt_the_hell.c4d I have a very
small area light in close proximity to the
sphere with the physical camera tag removed. I’ve done this to view the lights in
their ‘raw’ default intensity state.
figure 5.07
figure 5.05 (from example file watt_the_hell.c4d )
This small area light has a Radiance (W/
m²/sr) value of 20 and a Radiant power (W)
value of 5.97.
figure 5.08
In figure 5.08 I’ve changed the Area type to
Sphere. We’ll want to scale this down to represent a bulb.
Page 57
As I decrease the Spherical Area light radius
to approximately 5cm, you’ll notice that
the editor view becomes distracting and
overbright. This is a common nuisance that
requires only a simple logical understanding
to remedy.
Another quick render figure 5.11, Radiance
(W/m²/sr) value of 401 and a Radiant power
(W) value of 41
So you get the picture.
figure 5.09
figure 5.11 (from example file a_bulb_of_sorts.c4d )
Personally I stick with the native Cinema 4D
units for lighting, they don’t represent anything but I’m comfortable with that workflow. It’s not imperative to learn about wattage and luminous power etc, unless you’re in
a position to light based on pre-existing data.
It’s all about personal preference.
figure 5.10
VRay lights don’t have falloff parameters
as they do in Cinema 4D. They’re physical based and won’t respond to falloff size
change. So to remedy this overbright state
simply manually drag the larger spheres
handles and close them down to approximately the size of your light radius.
With this you’re controlling the falloff distance and editor visibility/brightness of said
light and not anything related to the actual
render.
figure 5.12 Is one better than the other?
The choice to use Rectangular lights vs
Spherical figure 5.12 one is a question of “what’s
right for the job” - They have uniquely different ways of casting shadows/light and should
represent the kind of light you’re looking
to cast into the scene. Though I find the
spherical light to be highly versatile in a lot
of cases, the rectangular shape is good for a
whole range of lighting situations.
You can manually do this in the standard
C4D light setting by clicking the light and
not the VRayLight tag. figure 5.11
figure 5.11
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Area Light - Light portals
We’ve taken a quick look at Area light settings, now we’ll dig a little deeper
In figure 5.13 we have a typical Sun/Sky setup
with a very small opening. This is allowing a
little light to enter the room, but not enough
samples are reaching the interior for a quality result. The first idea would be to totally
max out the IR map, DMC sampler settings
etc, but there’s a simpler way to approach this
with a Light Portal.
The light portal setting has effectively turned
this light source into a sort of directional
guide for the samples.
In my crap illustration below figure 5.15 you
can see that without the Light Portal, the red
samples miss the mark and don’t make it into
the scene. With the Light Portal activated,
the samples have assistance in their intended
direction .
Open scene Small_Hole.c4d and if you’d like to
render to the picture render for comparison.
figure 5.13
First thing to notice in the scene is an Area
Light that has been turned off. Opening the
light parameters via the Vray light tag reveals
what looks to be only a standard area light,
however the property ‘Light portal’ has been
switched from Normal to Portal Light.
Checking the light to on in the OM and rerendering will now show a much clearer and
less splotchy render. figure 5.14
figure 5.14
figure 5.15
The other solution is the Simple Light Portal
which ignores any lights/objects behind the
portal and takes only the environment color
into consideration. This can speed up the
workflow slightly.
Page 59
Light Portals can be helpful but are rarely
used in latest versions of Vray as the GI algorithm has become more refined. Though in
situations like this, they can be used to your
advantage.
Area Light - Dome
The Area light type - Dome is a similar to using a color or hdr effect as the Environment background
color, but uses direct sampling to provide a much more accurate result.
figure 5.16 (Environment tab from VRay Settings)
figure 5.16 (Environment from VRay Settings)
figure 5.17 (Environment slot VRay Settings)
In figures 5.16 & 5.17 I’ve loaded a *.hdr image
into the texture slot of the Environment
background and have a standard GI setup
ready to render.
figure 5.19
Controlling this light source is straight forward. Position of the light in your scene is
irrelevant, however rotation values will affect
the orientation of an image based map.
The resulting render figure 5.18 has been
processed much like a standard luminance
material. Light is being cast into the scene
but the sampling method is not direct.
A color/texture/material effect is loaded into
the slot (in this case ennis.hdr) and the result figure
5.20 is a directly sampled dome light.
While this is suitable for most tasks (especially with an accompanying light setup), if
you want some extra bang for your buck, the
Area light Dome is more powerful.
figure 5.18
Samples can be adjusted according.
Page 60
figure 5.20
Area Light - Mesh
Using a Mesh as a light source is one way to cast light from geometry. Though this effect does not differ
and is easier to setup using Direct Illumination in a luminance channel.
As you can see figure 5.23 there’s no difference
the two workflows, other than ease of setup.
A practical usage of this method is to create customized light shapes such as a curved
plane or to match the shape and size of a
pre-existing light fixture. Though I wouldn’t
recommend lighting exclusively with this
technique in mind, it can be perfect to add
the finishing touches to an interior scene.
figure 5.21
Prior to the creation of the Direct illumination method in the luminance channel, it
was not possible to pick and chose work
flows. In the scene from figure 5.24 Mesh lights
were used throughout the piece to light areas
that needed to match the shape of the opening.
In the simple scene Vray_Mesh.c4d the light
on the upper left figure 5.21 is utilizing the Vray
Light type - Mesh and has the cube object
loaded into the empty geometry slot figure 5.22
figure 5.22
The object on the right has a VRay material
with a Luminance material applied and the
direct illumination option switched on.
figure 5.23
figure 5.24 “Inspire city”
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Area Light - Remaining settings
We’ll take a brief at the remaining settings from the Area light tab.
Affect Reflections: With this option unchecked, the brightness of the light will be ignored by the material
reflectivity.
Invisible: All light sources are visible unless otherwise indicated. Unchecking this option will provide a
light source, thought the origin of the light will not be visible.
No Decay: All lights in VRay have decay (falloff) based on real world calculations. Enabling No Decay
will essentially create a light source with no falloff at all. This is not recommended when trying to realistically light a scene, but can be useful in product shots if you require an infinite light source.
Double sided: A rectangular area light emits light from the Z+ direction only, enabling Double Sided
enables the light to illuminate from both surface normals. *CHECK
Samples: As discussed on Page 32, the amount of samples used determines the quality of the light source.
Lights producing undesirable noise benefit from additional samples.
Store with Irradiance map Using this option, the light calculated from the Area map is processed and
stored during the Irradiance map calculation. Discussed on Page 55.
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IES lights
IES data is taken from existing real world lighting fixtures and is made available for users in varying
professions to download and utilize in their projects.
An IES represents the shape of the lights falloff, but not the falloff amount. In figure 5.25 it’s
easy to recognize the differences in how each
light reacts to the IES data.
Omni is the light type indicated to use when
working with IES files. Creating a standard
light and enabling shadows, you can then
quickly move over the IES tab and load your
desired IES file.
Open example file IES_scene2.c4d
figure 5.27
In this scene figure 5.27 the light is unchanged
and retains the default brightness as contained in the IES data. To increase brightness
you can enter a Lumens value for an increase
in intensity, this value would typically be
quite high. I’m going to increase to 10,000.
figure 5.25
Open example file IES_scene.c4d
The first thing you’ll notice in this scene if
using Cinema 4D version 12 or higher, is
that the visual reference of the IES light is
incorrectly oriented figure 5.26.
Enabling Soft shadows does as you would expect, it softens the shadow density, which is
occasionally desirable and only slightly more
time consuming to render.
A hint of color in the filter color will tint
the IES light to the desired value. Rarely are
lights 100% white, making a tint a worthwhile change. figure 5.28
figure 5.26
This is the standard rotational value of the
default light. To fix it, rotate the p axis (the blue
handle) to -90°. Note: Targets will always utilize
the P axis.
figure 5.28
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Final notes on lighting
The remaining light sources are Spot, Infinite and Parallel. I won’t cover these in detail because their parameters are logical and require no special attention.
In future PDF instructional manuals we’ll take a closer look at lighting individual scenes.
Lighting in VRay is a unique process, one that can be as simple as the Physical Sun/Sky setup or as complex as lighting a city. My advice is to stay away from the simplest work flow and push the boundaries of
what can be done with lighting and composition.
Before tackling a project that involves a lighting rig, try to think of the balance you want to strike beforehand. In a night time shot for example - Would it be wise to create the overall environment light first, fills
etc and then work your way down to the lighting fixtures? I would say not. My approach is to always start
small, lighting fixtures first, achieve a sense of balance with the smaller details and when you’ve refined
and refined some more, only then would it be time to look towards the bigger lights.
Lighting can be a tedious part of the process if you make it so, continuously rendering the same shot time
and time again. This is why I recommend a base test setting, where the results of your scene lights can
be visualized in a matter of seconds vs waiting 10 minutes every time you make a change. Get used to
switching out between crap settings and medium ones to ensure you get overall sense for your scene and
to ensure that with better settings, the lights will withstand scrutiny.
When you arrive to a point where the correct values flow, lighting is perhaps the most interesting part
of the project, after all this process is what brings your work to life. It makes or breaks your work, so pay
careful attention to what the masters do and try to replicate the best rigs without settling for mediocrity.
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Chapter 6: Environment Fog
Prior to there being a working fog solution in VRay, there were definite limitations when using the render
engine for environment design and landscapes. Eventually ChaosGroup introduced the Environment fog,
which is a unique and physically accurate calculation of scene fog. The concept may seem quite limiting,
“how often do I want fog?” Yet the implementation opens up a world of creativity.
Let’s first take a quick look at what it can do in terms of finished projects.
figure 6.1 ‘Sunday’
figure 6.2 ‘Fall’
figure 6.3 Modern fog test
The scene ‘Sunday’ figure 6.1 is initially setup with only a physical sun/sky, but due to the Environment fog
and the enabled Scatter GI parameter, the sun light is able to illuminate the fog. The result as in real life is
that the fog itself becomes a source of illumination for the scene and the actual sun light and it’s potential
shadow casting has diminished to such a degree that it’s almost completely invisible. An increase in exposure and an adequate interior lighting rig restores the balance.
The scene ‘Fall’ figure 6.2 is setup with Proxy objects and consists of around 2 billion polygons. Fog with GI
scattering is enabled and is indicated to reach a height of 4 meters at a distance of 50 meters. This clears
the way for sun to still have a visible affect on the scene, but creates a sense of depth that would otherwise
not be possible.
The scene ‘Modern fog test’ figure 6.3 was the first real test where I used the Environment fog parameters.
Given my lack of understanding at the time it’s easy to for me to critique the work. The fog height is essentially infinite, which under such heavy fog cover doesn’t allow any light penetration from the Sun.
Given an opportunity to re-work this piece, I would have chosen more fitting parameters.
So let’s do that, let’s figure out what works best by creating a fog lit scene.
Page 65
Open example file Home_fog.c4d
Here figure 6.4 we have another typical Sun/
Sky setup, pretty standard scene. We’re going
to spice things up with a little fog.
In the VRay settings rollout for Environment
we’re going to activate Environment Fog.
figure 6.6
If you’d like to run a test render, you’ll see the
results are almost completely black.
figure 6.4
First, let’s go to the editor camera and create
a primitive cube figure 6.5.
Add the Cube object to the open slot for
Gizmos and add the Sun object to the open
slot for Lights.
Another render reveals a shot almost identical to the original, minus the slightest hint of
haze figure 6.7.
figure 6.5
Manipulate the cube to extend the outside
of the building, without penetrating the the
window & building layer figure 6.6. We’re keeping the fog strictly outside.
figure 6.7
We’ll want to check the Scatter GI box.
This tells VRay to look at the Fog as a volume and calculate its light solution based on
the density of that matter. The scattering will
both illuminate the fog and determine how
much light can escape the solution.
Another render would still resemble that of
the original.
figure 6.5 - Cube has Xray effect for illustration only.
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To finally see a result of using the Environment Fog, we’ll want to manipulate the Fog
Distance parameter, bringing that numerical
value down from 1000 to around 100.
In figure 6.9 I’ve added two makeshift security
lights outside the building and included
those additions in the Environment fog Light
slot.
The change in distance affects the density,
visible fog at closer proximity is now thicker,
allowing less light to penetrate.
Your result may look slightly different than
mine figure 6.8 based on the exact shape of
your Gizmo geometry.
figure 6.9
You can see that this simple addition had
added to the fog illumination, which in turn
casts more unique light into the scene.
A couple of interior lights to compliment the
outside, a little furniture, materiality and you
have an interesting setup. Certainly something outside of the boring Physical sky look.
figure 6.8
The Gizmo object (setting geometry as the
fog) is the preferred workflow as this gives
us more control over the density of the fog.
Without a gizmo we’re using infinite fog
depth and using the Fog height parameter
which can be more difficult to control.
Sunlight is still able to penetrate the scene,
but has become obscured by the fog element.
Subtle compensation with exposure or an
interior lighting rig would be the next step.
figure 6.10
By adding some outside features, you’ll give
life and more depth to the exterior. In figure
6.11 the eye is drawn to the passers by, which
creates more interest.
It’s possible to use any shapes as a Gizmo
object no matter how irregular, allowing you
to experiment with just about any geometry
imaginable.
It’s also possible to use as many light as
required in order to scatter light through the
fog density.
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figure 6.11
Links
I’d have spent some time teaching VRay for animation, but upon review there is little more I can say than
what has already been clearly spelled out on the VRay message board by ‘STRAT’
These step by step guides will get you through both ‘GI object animation’ and ‘GI camera animation’
Though if you have any remaining questions, please feel free to email me @ thec4dvault@hotmail.com
http://forum.vrayforc4d.com/showthread.php?t=7727&highlight=object+animation
http://forum.vrayforc4d.com/showthread.php?t=7728
Even with knowledge of VRayForC4D, I still refer to these tutorials as a step by step checklist.
For Clarification and further reading on any of the subjects covered here, the VRay manual is an excellent
resources with up to date information.
http://vrayc4d.com/manuals/booktree
Here’s a couple of older tutorials I created with regard to illuminating skyscrapers
You may or may not find these useful.
http://vrayc4d.com/manuals/vrayc4d-tutorials/skyscraper-lighting-inthecity
http://vrayc4d.com/manuals/vrayc4d-tutorials/city-illumination-inthecity
For Free models
http://archive3d.net/
And the best collection of textures available online
http://www.cgtextures.com/
And finally - Exclusively VRay based materials
http://www.vrayforc4d.com/portal/materials/
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That’s a wrap
I hope your experiences with this booklet have been positive.
If you have any additional question for clarification please contact me at
thec4dvault@hotmail.com
Join me again in the near future.
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