Animating a flock of birds a flock of birds in Maya

Transcription

Animating a flock of birds a flock of birds in Maya
Animating a flock of birds in Maya
JMG, ANDA Spring 2009
This tutorial shows how to model and animate the wings of the bird. The second part covers setting the
bird on a motion path and duplicating one bird in order to create a flock of birds.. You can skip the first
part if you already have an animated bird.
Part one – Modeling and animating the wings of one bird
The body of the bird can be created from a subdivision model converted to polygon (the
he step by step is at
http://www.tinkering.net/pdf/bird.pdf
pdf/bird.pdf) or from a polygon box primitive. The box is divided using
u
the Split
Polygon tools and the Insert Edge Tool. Polygon > Edit Mesh > Split
lit Polygon Tool and Polygon > Edit
Mesh > Insert Edge Tool.
After modeling the body of the bird, I also chose to model half of a bird by selecting
cting the faces on one half
and deleting them. I divided the model along the longitudinal axis by inserting an Edge in the center of the
bird. Polygon > Edit Mesh > Insert Ed
Edge Tool.
Prepare
re the modeling of the wings by a
aligning the polygons that you plan to extrude. You can test the
alignment of the polygons by starting and undoing several extrusions.
Test extrusion to get more familiar with the process.
The tip of the wing requires your attention, repeat extrude and scale several times. Test in the Smooth
mode. Select the half bird (green selection), ggo to Polygons > Mesh > Smooth
Let’s duplicate mirror the half bird.. Select as an object, green selection. Go to Polygon > Edit > Duplicate
Special, translate = 0,, rotate = 0, scale x=
x=-1, y=0, z=0
Align the two half birds next to each other, make sure that the vertices and edge aare
e aligned
SHIFT select the two halves. Select as an object, green selection, go to Polygon > Mesh > Combine
And merge the polygons. Go to Polygon > Edit Mesh > Merge, move the slider of the merge
m
threshold by
very small increments.
Lets create a rig for the bird. Go to Animation > Skeleton > Joint Tool. Trace the joints starting from the
ponit located in the middle of the bird, between the wings, and moving towards the edge of the bird.
bird
Draw a chain of joints following the right wing
Draw an identical chain of joints (with the same number of joints and same locations) following the left
wing. You can duplicate the previous chain
Draw a third chain of joints from body to head,
Draw a fourth chain of joints from body to tail.
.
Let’s parent
arent each joint of each chain to joint 1. In Outliner, select a joint MMB + DRAG on Joint 1
Move (translation only,, NO rotation) some of the joints in order to align the rig in the center of the bird.
bird
SHIFTT select joint 1 (the skeleton) and the mesh. Go to Animation > Skin > Bind Skin > Smooth Bind
Let’s create a simple animation of the wings with a flight cycle of 300 frames.
Frame 0
Frame 75
Frame 150
Frame 175
Frame 300
The cycle will include
(Frame 0 : wings in default position <> Frame 75 : wings going up <> Frame 150 : wings return to default
position <> Frame 175 : wings going down <> Frame 300 : wings return to default position)
position
Let’s animate the right wing. First, we create three intermediary keyframess in order to establish the
default position of the wings at 0, 150 and 300
300.
Select a lower joint at the beginning of the left wing. Create 3 keyframes at 0, 150 and 300.
300 (press S)
Select a middle right wing joint.. Create 3 keyframe s at 0, 150 and 300. (press S)
Go to keyframe 75, rotate the middle right wing joint, down, create a key. Please note that adding
a
a slight
translation to the wing can ease the visual look and feel of the rotation deformation.
Go to keyframe 175, rotate the middle joint of the right wing, up, create a key,
Select a lower right wing joint. Create 3 default keyframes at 0, 150 and 300. (press S)
Select a middle left wing joint.. Create 3 default keyframes (press S) at 0, 150 and 300. (press S)
Go to keyframe 75, rotate and slightly move the middle joint of the left wing, down, create a key,
Go to keyframe 175, rotate and slightly move the middle joint of the left wing, up, create a key,
Check the animation, both wings are now moving together.
Add opposite a few keyframes with
ith opposite motions of tail and head.
You can view all the keyframes for your animation in the Dope Sheet,
Select Joint 1 in Outliner. Go to Edit > Select H
Hierarchy. This will make sure that all the joints are visble in
the Dope Sheet window. Go to Window > Animation Ed
Editors > Dope Sheet.
Lasso on the keyframes that you choose to select
select.
RMB in the green window,, select View > Frame All
All. You can select the move tool > MMB on the selected
s
keyframe(s) and move the keyframe right or left on the timeline.
Let’s cycle the animation in the Gaph Editor. The Graph Editor can be used to visualize and edit each
motion channel thru time. Cycling the motion will repeat the animation beyond the keyframes that you
have already created.
Select Joint 1 in Outliner. Go to Edit > Select H
Hierarchy. Go to Window > Animation Editors
tors > Graph Editor
RMB in the grey window,, select View > Frame All
RMB in the grey window, select Curves > Post Infinity > Cycle
Cycle.. Test the animation over 1200 frames.
Let’s put the animated bird on a motion path.
First we create a curve. Go to Create > CV Curve. Click at least 3 point on the grid in
n the top view.
view
Close the curve. Go to Surfaces > Edit Curve
Curves > Open/Close Curves,, check the ignore option for a circular
curve. Check Preserve for a curve identical to the one that you created.
SHIFT select Joint1 and the curve.. Go to Animation > Animate > Motion Path
Paths > Attach to Motion Path
The bird follows the motion path while playing the wings animation
You can adjust the Motion
otion Paths settings in the Attribute Editor in order to fly the bird in the right
direction
Let’ss adjust the length of the motion path or the speed of the bird.
Select the Curve as an object (green selection) Go to Window > Hypergraph Connections, select the
Motion Path icon (yellow
llow selection). Go to Graph > Input
Input-Output
Output Connections > Motion Path Values. Edit
the value in the Attribute Editor.
Let’ss duplicate the animated bird on a path.
First, let create a group. We will duplicate the group as a system including the bird
bird’ss mesh,
me the joints, the
wing animation,, the curve and the motion path
path.
Go to Create > Empty Group
Let’s parent each element of the group including mesh, joint1, curve with the Empty Group.
G
MMB and drag for joint1. MMB and drag for the mesh. MMB and drag for curve
Second, select the Empty Group only!! Go to Edit > Duplicate with Transform > select Instance. The shape
of the flock of birds will follow values
alues of Translate, Rotate and Scale. For example, Translate Y puts the
birds on top of each other. Rotate
tate Y offsets the starting points of the animations on the curves. Scale XYZ
puts the flying bird in a fake perspective
perspective.
Play the animation. Render the animation. Please note that you may need to create a new shader for each
clone.
RMB on a clone > select Assign New Material > for example Lambert or Blinn.
Repeat for all the clones. Save and Render your animation.
Now it’s time to import yourr file inside the fluid 3D container created for the clouds in the sky.
The step by step can be found at http://www.tinkering.net/pdf/
http://www.tinkering.net/pdf/clouds.pdf