Creates an animation using multi-chain IK handles attached to a skeleton.
Run IK Options
All – If you select the simulation runs on all root-level skeletons that have multi-chain IK handles, whether or not they are picked.
A root-level skeleton is a joint node with no ancestors that are joint nodes. This joint node and all joint nodes below it make up a skeleton.
Active – If you select the simulation runs on all joint nodes on the skeletons that are active.
The skeletons are defined from the picked joint node and all joint nodes below it. Anything that is picked but is not a joint node will be ignored.
Multi-chain IK animation must be run from the same initial state to get the same animation.
For with multi-chain handles, the skeleton must be in a known starting position.
If you want to render only a subset of the frames in your animation, you must still follow the above steps and run IK for the whole range of animation.
All – The default frame range includes the range of animation for all the IK handles attached to the picked skeletons.
Current – The IK simulation starts at the current frame and runs until you press the key.
Option Window – Lets you specify start and end frames. When you click this button, these controls appear:
You can specify the frame range for the IK simulation by typing the and values. These values apply for running the IK simulation only if is selected.
This is how often keyframes are set for a skeleton during the IK simulation. If the option is ON, some of these keyframes may be removed after the simulation is complete.
This is the increment at which the simulation is run. For example, if the value is 0.2 frames and the value is 1.0, then the IK simulation runs for 5 steps for each frame before setting a keyframe in the skeleton.
Since the IK handle animation is sampled at different frame values, inverse kinematics may cause a jump from one frame to another. Choosing a smaller value makes the inverse kinematics solution smoother, even though keyframes are generated only at the increments.
If the option is toggled ON (indicated by a check-mark), all the animation curves that were created in the skeleton during the IK simulation are simplified after the simulation to remove as many keyframes as possible within the given tolerance, while still preserving the shape of the original curve.
When it is checked, the following additional controls appear:
Translation/Rotation Tol – These tolerance values are used for simplifying the curve. A tolerance specifies how much the simplified curve may differ from the unsimplified curve at each keyframe.
These two sliders let you specify different tolerances for curves that are animating joint rotation versus those animating joint translation. For example, the default tolerance for rotation is higher than that of translation because a difference of one degree of rotation is usually less noticeable than a difference of one unit of translation.
If this option is set ON, all multi-chain IK handles are disabled after the Run IK simulation.
If this option is set ON, each time a keyframe is computed, the skeletons are redrawn in their configuration at that frame. This gives instant feedback for the simulation.
If a large model is simulated for many frames, redrawing at every value can slow down the simulation. If you toggle off, the skeletons are redrawn only at the beginning and end of the simulation.
If this option is set on, any single-chain IK and spline IK animation information is also translated into rotational information on the skeleton in addition to the translated multi-chain IK. When you select this option, the following additional controls are displayed:
This option turns off the single-chain and spline IK handles after is applied. To turn the single-chain and spline IK handles back on, use Edit > Rest Pose > Set Rest Pose, or the .
If you are going to render an animation with , or (see Render > Globals for details), you may want to use motion blur compensation, field render compensation, or both during the simulation. These compensations only apply on animations translated from single-chain or spline IK handles.
– simulation sets extra keyframes at motion blur sample times if interpolation between keyframes would yield wrong values for motion blur. The used for the motion blur compensation is set in Render > Globals > Blur Effects.
– simulation sets extra keyframes at half frames if interpolation between keyframes would yield wrong values for half frames. Field rendering information is set in Render > Globals > Image File Output.
– does not occur (this is the default).
– Both motion blur and field rendering occur. By default, is set to . Otherwise, the following additional controls appear:
If set to ON, animation is not translated to the skeleton. Instead, the compensation information appears at the prompt line; you are told if compensation is needed and at which keyframes it should be applied.
These tolerance values are used to determine if a compensation between two keyframes is needed or not. Each time the compensation procedure checks an animation, if the real translation value is within the tolerance, no compensation happens. Otherwise a new keyframe is inserted with the real value.