Show in Contents
Add to Favorites
Home: Autodesk Maya Online Help
Planning an animation for an IK system
Lesson 5: Inverse kinematics
Beyond the lesson
Animating an IK system
The animation sequence occurs over a 180 frame
period. Before you begin to set keyframes you set the playback range
in the Animation Timeline/Slider.
To
set the playback range in the Time Slider
- In
the Animation Time and Range Slider, set the following start and
end times for the animation:
- Playback
Start Time: 1
- Playback
End Time: 180
To simplify the keyframe workflow, you first
set keyframes for the mechanical arm, and then set keyframes for
the weight attributes of each parent constraint for the cargo box.
To
set keyframes for the mechanical arm
- In
the Timeline, set the Time Slider to frame 1.
- Select
only ArmControl.
- In
the Channel Box, set the following
values:
- Translate
Y: 0
- Translate
Z: -13
- From
the main menu, select
Animate > Set Key.
To set the remaining keyframes for the arm and
the swivel base, use the table below as a guide, and set the attributes
in the following order:
- Set
the frame using the Time Slider.
- Set
the attributes for the object in the ChannelBox.
- Set
the keyframe (
Animate > Set Key).
NoteDon’t be concerned if the list of keyframes
indicates to set a key twice for the same position over two frames.
This is necessary to animate the parent constraint weights over
a period of one frame.
| Frame |
Select |
Set attribute |
Select |
1
|
ArmControl
|
TransY: 0 TransZ: -13
|
Set Key
|
30
|
ArmControl
|
TransY: 7 TransZ: -13
|
Set Key
|
59
|
ArmControl
|
TransY: -9 TransZ: 0
|
Set Key
|
60
|
ArmControl
|
TransY: -9 TransZ: 0
|
Set Key
|
80
|
ArmControl
|
TransY: 6 TransZ: -13
|
Set Key
|
80
|
SwivelBase
|
RotateY: 0
|
Set Key
|
100
|
SwivelBase
|
RotateY: -100
|
Set Key
|
100
|
ArmControl
|
TransY: 6 TransZ: -13
|
Set Key
|
120
|
ArmControl
|
TransY: -9 TransZ: 0
|
Set Key
|
121
|
ArmControl
|
TransY: -9 TransZ: 0
|
Set Key
|
140
|
ArmControl
|
TransY: 6 TransZ: -13
|
Set Key
|
140
|
SwivelBase
|
RotateY: -100
|
Set Key
|
160
|
SwivelBase
|
RotateY: 0
|
Set Key
|
160
|
ArmControl
|
TransY: 6 TransZ: -13
|
Set Key
|
180
|
ArmControl
|
TransY: 0 TransZ: -13
|
Set Key
|
Once the keyframes for the mechanical arm are
set you can use the playback controls to playback the motion for
the mechanical arm.
To
playback the animation using the playback controls
- Click
play on the TimeSlider playback controls to play the animation.
The mechanical arm animates over 180 frames.
The cargo box does not move because the weight attributes for the
parent constraints are set to zero and have not yet been set for
the animation.
- Click
stop on the TimeSlider playback controls to stop the playback.
In the next steps, you set keyframes for the
parent constraint weight attributes so the cargo box is lifted,
moved, and placed in the second location. You set keys for the weight
attributes on the parent constraint node.
To
set keyframes for the parent constraint weights
- In
the Timeline, set the Time Slider to frame 1.
- In
the Hypergraph, select the node
for the parent constraint directly below CargoBox.
- In
the Channel Box, set the following
values (if they are not set already):
- ArmControl
W0: 0
- Platform
W1: 0
- In
the Channel Box, select the ArmControl and Platform channels
by shift-clicking on the names.
- Right-click
on either one of the selected names.
A drop-down list appears.
- From the drop-down list, choose Key
Selected.
Key Selected sets a keyframe for the selected
attributes only.
To set the remaining keyframes for the parent
constraint weights, use the table below as a guide, keeping in mind
that you set the attributes in the following order:
- Set
the frame using the TimeSlider.
- Set
the parent constraint attributes in the ChannelBox.
- Right-click
on the selected names and select Key Selected.
| Frame |
Select |
Set attribute |
Select |
1
|
CargoBox parentConstraint
|
ArmControl W0: 0 Platform W1: 0
|
key selected
|
59
|
CargoBox parentConstraint
|
ArmControl W0: 0 Platform W1: 0
|
key selected
|
60
|
CargoBox parentConstraint
|
ArmControl W0: 1 Platform W1: 0
|
key selected
|
120
|
CargoBox parentConstraint
|
ArmControl W0: 1 Platform W1: 0
|
key selected
|
121
|
CargoBox parentConstraint
|
ArmControl W0: 0 Platform W1: 1
|
key selected
|
To
playback the animation using the playback controls
- Click
play on the TimeSlider playback controls to play back the animation.
The mechanical arm moves through the motion
of the animation and picks up and moves the cargo box to the new
location.
- Click
stop on the TimeSlider playback controls to stop the playback.
You have completed this lesson.
