Houdini 21.0 Nodes Geometry nodes

Motion Mixer geometry node

Combines animation clips and effects to generate character animation.

On this page
Since 21.0
This feature is still under development. The current functionality is unfinished and subject to change, and may have thin or no documentation. Please bear this in mind when using it.

Combines animation clips and effects to generate character animation in a timeline-based view. See the motion mixer page for more information.

State

The viewport state allows you to see the motion of the characters generated by the motion mixer.

Parameters

Mixer Properties
Characters

Filter

The characters from the animation scene to use in the motion mixer.

Display

A display filter on the characters. A hidden character still produces animation but is not displayed in the viewport.

Output

Mode

Sets the output of the motion mixer:

Controls

The skeleton representing the control transforms, named MixerAnim.skel, output in a character folder structure.

Skeletons

The skeleton used for the bone deformation, output in a character folder structure.

Shapes

The deformed geometries in a character folder structure.

Control Shapes

The control shapes in a character folder structure.

Animation Clip

The full animation scene with the motion mixer animation output as an animation clip.

Motion Clips

The motion clips of the control transforms, MixerAnim.skel, output in a character folder structure.

Animation Clip

When Mode is set to Animation Clip, this is the path to the output animation clip in the character folder structure.

Labels

When turned on, adds a label above the character.

Start Frame

The start frame used for baking animation.

End Frame

The end frame used for baking animation.

Rate

The sampling rate, in frames per second, for baking animation and clip evaluation.

Mixer

Solo Track

The name of the soloed track. The Solo button in the motion mixer pane track header drives this value. There can only be one soloed track at any given time.

Track

The number of tracks in the motion mixer. See the track parameters.

Transform

Track Effects

The number of effects on the track. See the track effects parameters.

Track Clips

The number of clips in the track. See the clip parameters.

Markers

The number of markers in the motion mixer. See the marker parameters.

Notes

The number of notes in the motion mixer. See the note parameters.

Track parameters

Enable Track

When turned on, enables the track. The Mute button in the motion mixer pane track header drives this value.

Weight

An animatable weight for the track blending contribution.

Joints

A joint filter used for track blending. Only selected joints affect the previous track.

Characters

A character filter for track blending.

Blend Mode

Specifies how the track weight blends with the previous track.

Local

Blends the local transforms of the MixerAnim.skel.

Additive

Blends by computing the difference with the rest pose and adding it to the previous track.

Global

Blends the world transforms of the MixerAnim.skel and recomputes the local transforms.

Replace

Don’t perform blending. Use the track as is.

Blend Parent

The parent joint used to help with partial blending. This reparents the current track animation using a common joint and can help with blending upper body animation when the IK controls are not parented to the spine.

Locked

When turned on, locks the track to prevent edits to the clips on the track. The Lock button on the motion mixer track pane header drives this value. This has no effect on cooking.

Color

The track color in the motion mixer pane. This also affects the motion mixer viewer state when tracks are selected. If the color is black, the track uses the default color.

Transform parameters

These parameters are for the track transform handle.

XfoOrder

The handle transformation order:

  • Scale Rot Trans

  • Scale Trans Rot

  • Rot Scale Trans

  • Rot Trans Scale

  • Trans Scale Rot

  • Trans Rot Scale

RotOrder

The handle rotation order:

  • Rx Ry Rz

  • Rx Rz Ry

  • Ry Rx Rz

  • Ry Rz Rx

  • Rz Rx Ry

  • Rz Ry Rx

Translate

The translation of the track along the X, Y, and Z axes.

Rotate

The rotation of the track about the X, Y, and Z axes.

Scale

The scaling of the track along the X, Y, and Z axes.

Pivot Translate

The pivot translation along the X, Y, and Z axes.

Pivot Rotate

The pivot rotation about the X, Y, and Z axes.

Track effects parameters

Enable Effect

When turned on, enables the track effect. The Mute button in the motion mixer pane effect header drives this value.

Mode

Specifies when the track effect is applied.

Local

A local effect is applied after all the clips are sequenced within the current track. The effect is independent of the previous track’s blending.

Global

A global effect is applied after all the clips are sequenced within the current track, the local effects are applied, and the current track is blended with the previous track. The effect is applied on top of the blended tracks.

Blend

The amount of the track effect to apply. This is a common parameter shared by all the track effect types and is displayed in the motion mixer pane as a slider in the track effect header and an editable curve in the timeline. Not all effects blend the same way.

Clip parameters

Track Clip

Enable Clip

When turned on, enables the clip on the track. When turned off, the clip does not play.

Source

The animation source from the animation clip folders in the motion mixer pane. This is automatically set when doing a drag and drop operation from the clip folders onto the timeline. The source can be specific to a character (/electra/jump) or scene (/*/scene_anim).

Start

The start frame of the clip (including the cycled regions). This defines the left side of the clip boundary in the timeline.

End

The end frame of the clip (including the cycled regions). This defines the right side of the clip boundary in the timeline.

Speed

The clip playback speed. A value of 1 doesn’t affect the playback speed. A value less than 1 slows the playback and a value greater than 1 speeds it up. Modifying the speed affects the length of the cut range in frames.

Position

The position in the timeline that is the start of the source animation (not including the cycled regions).

Cut Start

The frame within the source animation where the playback starts. The Cut Start and Cut End parameters define the clip playback range that is used for cycling.

Cut End

The frame within the source animation where the playback ends. The Cut Start and Cut End parameters define the clip playback range that is used for cycling.

Extend Before

Specifies the behavior before the clip (if there are no other clips before it):

Hold

Holds the clip’s first pose.

None

Holds the rest pose.

Extend After

Specifies the behavior after the clip (if there are no other clips after it):

Hold

Holds the clip’s last pose.

None

Holds the rest pose.

Color

The color of the clip in the motion mixer pane.

Display

When turned on, displays the Color on the character in the motion mixer viewer state.

Cycle

These parameters specify the cycling behavior of clips.

Cycle Before

Specifies the behavior before the source animation clip but within the cycled clip boundaries:

Hold

Holds the first pose from the source animation clip.

Cycle

Cycles the animation before the source animation clip.

Cycle After

Specifies the behavior after the source animation clip but within the cycled clip boundaries:

Hold

Holds the last pose from the source animation clip.

Cycle

Cycles the animation after the source animation clip.

Blend Frames

The number of frames in which to blend between the cycled regions.

Offset

Specifies how to offset the character between the cycled regions.

Cycle Joint

When Offset is set to Automatic, this is the joint to match between the cycled regions.

Cycle Translate

When Offset is set to Automatic or Manual, this is the translation between the cycled regions.

Cycle Rotate

When Offset is set to Automatic or Manual, this is the rotation between the cycled regions.

Transform

These parameters are for the clip transform handle.

XfoOrder

The handle transformation order:

  • Scale Rot Trans

  • Scale Trans Rot

  • Rot Scale Trans

  • Rot Trans Scale

  • Trans Scale Rot

  • Trans Rot Scale

RotOrder

The handle rotation order:

  • Rx Ry Rz

  • Rx Rz Ry

  • Ry Rx Rz

  • Ry Rz Rx

  • Rz Rx Ry

  • Rz Ry Rx

Translate

The translation of the clip along the X, Y, and Z axes.

Rotate

The rotation of the clip about the X, Y, and Z axes.

Scale

The scaling of the clip along the X, Y, and Z axes.

Pivot Translate

The pivot translation along the X, Y, and Z axes.

Pivot Rotate

The pivot rotation about the X, Y, and Z axes.

Transition

Mode

Sets the transition behavior between clips. The selected clip drives the transition with the previous clip (the clip on its left).

None

Holds the selected clip’s first pose.

Hold

Holds the previous clip’s last pose.

Blend

Blends between the previous clip’s last pose and the selected clip’s first pose.

Track Blending

In Shape

Sets the track blending behavior for the left side of the clip. The shape of the curve also depends on the In Handle and In/Out Value.

None

The blend value is 0.0 within the blend region.

Linear

Linear blending from 0.0 to In/Out Value within the blend region.

Ease

Ease curve from 0.0 to In/Out Value within the blend region.

Ease In

Ease In curve from 0.0 to In/Out Value within the blend region.

Ease Out

Ease Out curve from 0.0 to In/Out Value within the blend region.

Ease ^2

Squared Ease curve from 0.0 to In/Out Value within the blend region.

Ease In ^2

Squared Ease In curve from 0.0 to In/Out Value within the blend region.

Ease Out ^2

Squared Ease Out curve from 0.0 to In/Out Value within the blend region.

Out Shape

Sets the track blending behavior for the right side of the clip. The shape of the curve also depends on the Out Handle and In/Out Value.

None

The blend value is 0.0 within the blend region.

Linear

Linear blending from In/Out Value to 0.0 within the blend region.

Ease

Ease curve from In/Out Value to 0.0 within the blend region.

Ease In

Ease In curve from In/Out Value to 0.0 within the blend region.

Ease Out

Ease Out curve from In/Out Value to 0.0 within the blend region.

Ease ^2

Squared Ease curve from In/Out Value to 0.0 within the blend region.

Ease In ^2

Squared Ease In curve from In/Out Value to 0.0 within the blend region.

Ease Out ^2

Squared Ease Out curve from In/Out Value to 0.0 within the blend region.

In/Out Handle

In and Out frame offset values from the left and right side of the clip. This defines the blend region at both ends of the clip.

In/Out Value

Single In and Out frame offset value defining the middle blend value of the clip.

Marker parameters

A marker is a vertical dotted line in the motion mixer pane timeline that allows you to mark a certain position in the animation.

Offset

The position of the marker in the timeline, in frames.

Length

The frame duration of the marker.

Note

The text to store with the marker.

Color

The color of the marker.

Note parameters

A note is text that is added to the motion mixer pane timeline.

Label

The label/title on the note.

Note

The text to put in the note.

Color

The color of the note.

Position

The position of the note in the timeline, in frames.

Inputs

APEX Scene

An animation scene with animation clips, in a character folder structure.

Outputs

Output

The output specified in the Mode parameter in the Mixer Properties, Output section.

See also

Geometry nodes