LimbPhases

The LimbPhases panel provides global settings for the motion of arms and legs in CATMotion.

• CATMotion Editor > Hierarchy panel > Click LimbPhases.

Interface

The upper part of the panel contains controls for footprints, while the lower section contains phase sliders for controlling the relative motions of the limbs.

FootPrints group

Footprints are helper objects that show and let you edit individual foot placement. As you edit the footprints the pelvis of the rig automatically repositions itself.

Note: You can animate footprints. For instance, you can keyframe the location of footprints to create actions such as a character slipping as it runs around a corner. You can also bind footprints to space warps, or use the Attachment constraint to make a character walk over an animated surface.

Tip: The extent to which editing a footprint affect the location of the hub depends on the number of legs on the hub. For example, if a hub has two legs, the hub positions itself halfway between its footprints. If a hub has four legs the hub will move a quarter of the distance towards the footprint.

Step Masks

When on, the rig automatically comes to a stop when successive footprints are layered on top of each other; that is, when the Path Node stops, and starts walking again when the Path Node starts moving again.

Note: The cessation and restarting of the walking motion is not immediate. The rig usually finishes the last step for a few frames after the Path Node stops, and starts walking again shortly before the Path node begins moving after the stop.

Create

Click to show footprints in order to view and edit them.

Delete

Removes the footprints. The software remembers the footprints and any edits, but any footprint animation is lost. Use Create to restore the footprints.

Selected/All

This choice determines whether the Reset and Pick Ground commands (see following) affect only selected footprints or all footprints.

Reset

Returns footprints to their original, unedited positions.

Pick Ground

Automatically aligns created footprints to a ground surface, such as a Plane primitive with the Ripple modifier applied. After clicking Pick Ground, select the ground object.

Tip: If Auto Key is on, using Pick Ground will key the footprints, so you can fit the footprints to an animated surface by applying Pick Ground every fourth or fifth frame. This is a more intuitive way to constrain your footprints to an animated surface than using an Attachment constraint and constraining each footstep manually, because the Path Node and changes to Global settings are respected.

[limb phase sliders]

Limb phases can also be though of as limb cadence, and affect the timing of the motion of the limbs.

The LimbPhases panel contains a slider for each limb on your character. Each arm and leg is driven by a phase offset. The phase offset defines the overall offset of the motion of that limb relative to the overall motion of the body. If several sliders are at the same value, the respective limbs move at the same time. If the sliders are exactly half a slider length apart in value, then the limbs will be exactly out of phase. The legs on a biped should be exactly out of phase so that each leg is taking steps when the other leg is planted on the ground.

Tip: Each slider’s label is the limb name, which you can edit in the Modify panel when a limb bone is selected. See Using CAT's Naming System. If you modify a limb name while the LimbPhases panel is displayed, refresh the panel by switching to a different panel and back again.