Houdini 20.0 Nodes Geometry nodes

MotionClip Retime geometry node

Adjusts the timing of a MotionClip

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Since 18.5

This SOP provides an interface from retiming its input MotionClip by altering the time attribute of the poses or by resampling the MotionClip. This SOP also provides controls to alter the left and right end behaviors of the output MotionClip.

When altering the time attribute of the poses, this SOP provides controls to crop and shift the timing of a MotionClip as well as change its playback speed by a constant positive factor.

This SOP provides three modes to resample the MotionClip: Resample By Time, Resample By Frame, and Resample By Speed. For each of these modes, parameters are provided to define the frame range and sample rate of the output MotionClip.

When in the Resample By Time and Resample By Frame modes, this SOP provides a parameter to define the function of time used to sample the input MotionClip. The units of this function are determined by the mode. These modes are simiilar to the By Time and By Frame modes on the Retime SOP.

When in the Resample By Speed mode, this SOP provides a parameter used to define the playback speed of the MotionClip. This parameter can be animated to alter the playback speed of the MotionClip over time. This mode is similar to the By Speed mode on the Retime SOP.

State

This viewport state allows you to visualize a MotionClip or its evaluated poses over time using a color ramp, and it is available for every MotionClip SOP node that outputs a MotionClip.

MotionClip viewport state interaction

You can select individual joints from the current pose in the MotionClip viewport state. For the selected joints, you can then use the Evaluate Pose mode to view just the current pose, its selected joints, and the motion trails for those joints.

rFoot and lFoot joints selected, Mode = Evaluate Pose, Color = White to Red
MotionClip viewport state toolbar

Mode

Determines the MotionClip information that is displayed in the viewport.

MotionClip

Displays all the MotionClip’s poses.

Mode = MotionClip

Evaluate Pose

Displays a single MotionClip pose at the current time.

Mode = Evaluate Pose

Transparent MotionClip

When turned on, the MotionClip’s poses are displayed as fainter lines, making it easier to see the scene behind the MotionClip, as well as the evaluated pose.

Color

Applies the selected color ramp preset to the MotionClip’s visualization in the viewport. This color ramp helps to visualize changes to the MotionClip or individual poses over time.

Mode = Evaluate Pose, Color = White to Red

Extend Color

Determines how the poses outside of the MotionClip’s defined animation start and end range are visualized in the viewport.

Hold

Holds the color values at the ends of the range.

Mode = MotionClip, Color = Plasma, Extended Color = Hold

Gray

Poses outside the animation start and end range are colored gray.

Mode = MotionClip, Color = Plasma, Extended Color = Gray

Hide

Hides the poses outside the animation start and end range.

Mode = MotionClip, Color = Plasma, Extended Color = Hide

Parameters

Timing

Evaluation Mode

Controls how the time of the MotionClip poses are computed and controls whether the MotionClip is resampled.

Range Shift

The timing of the poses will be cropped and shifted without resampling the MotionClip.

This mode is similar to the Range Shift mode on the Retime SOP.

Resample by Time

The MotionClip will be resampled and the evaluation time of the input MotionClip is determined by the Time function.

This mode is similar to the By Time mode on the Retime SOP.

Resample by Frame

The MotionClip will be resampled and the evaluation time of the input MotionClip is determined by the Frame function.

This mode is similar to the By Frame mode on the Retime SOP.

Resample by Speed

The MotionClip will be resampled and the evaluation time of the input MotionClip is calculated from the start of the Output Range and the Speed function.

This mode is similar to the By Speed mode on the Retime SOP.

By Shift

These parameters are used to crop and shift the time parameter on the poses of the input MotionClip.

These parameters are only available when Evaluation Mode is set to Range Shift.

Trim Outside Samples

The samples of the MotionClip which are cropped by the Animation Start and Animation End parameters will be deleted.

Animation Start

The output MotionClip will begin at this frame of the input MotionClip.

Animation End

The output MotionClip will end with this frame of the input MotionClip.

Playback Start

The output MotionClip’s playback will begin at this frame.

Speed Factor

A constant speed factor. The playback speed of the output MotionClip will be multiplied by this value. This is applied after any clamping is performed from the Animation Start/End parameters.

Resample

These parameters are used to resample the input MotionClip.

These parameters are only available when Evaluation Mode is set to Resample by Time, Resample by Frame, or Resample by Speed.

Time

The function of time in seconds used to resample the input MotionClip over the Output Range. If this is disabled, a function of $T will be used instead.

This parameter is only available when Evaluation Mode is set to Resample By Time.

Frame

The function of time in frames used to resample the input MotionClip over the Output Range. If this is disabled, a function of $FF will be used instead.

This parameter is only available when Evaluation Mode is set to Resample By Frame.

Speed

The function of speed used to calculate the times at which the input MotionClip will be resampled over the Output Range. If this is disabled, a constant of 1 will be used instead.

This parameter is only available when Evaluation Mode is set to Resample By Speed.

Output Frame Range

The range of the output MotionClip in frames. If this is disabled, the range defined within the clipinfo dictionary attribute on the input MotionClip will be used instead.

This parameter is only available when Evaluation Mode is set to one of the resample modes.

Output Sample Rate

The sample rate of the output MotionClip. If this is disabled, the rate defined within the clipinfo dictionary attribute on the input MotionClip will be used instead.

Repack Attributes

When enabled, the attributes defined by the Rest Attributes and Animated Attributes patterns will be evaluated from the input MotionClip and packed into the output MotionClip’s poses. This will result in all of these attributes becoming animated attributes on the output MotionClip.

For more details on what distinguishes an animated attribute from a rest attribute, see the Attributes folder on the MotionClip Evaluate SOP.

Tip

To maintain the attributes which were previously animated without adding any additional attributes to the poses, toggle Repack Attributes on, clear Rest Attributes, and set Animated Attributes to *.

Theses are the default values for these parameters.

Rest Attributes

The attributes that should be unpacked from the rest pose of the input MotionClip. All attributes that match this pattern will become animated attributes on the output MotionClip.

Animated Attributes

The attributes that should be evaluated from the animated poses of the input MotionClip. All attributes that match this pattern will remain animated on the output MotionClip.

End Behavior

Left End Behavior

Sets the left end behavior of the clip. This determines how the animation should behave when it is evaluated before the start of the MotionClip.

Clamp

The first and last poses will be extended out indefinitely.

Loop

The animation will repeat from the beginning.

Mirrored Loop

The animation will repeat in reverse.

Right End Behavior

Sets the right end behavior of the clip. This determines how the animation should behave when it is evaluated after the end of the MotionClip.

Clamp

The first and last poses will be extended out indefinitely.

Loop

The animation will repeat from the beginning.

Mirrored Loop

The animation will repeat in reverse.

Inputs

MotionClip

The MotionClip to be adjusted.

Outputs

MotionClip

The MotionClip on the first input after having been retimed.

Examples

SimpleMotionClipRetime Example for MotionClip Retime geometry node

This example demonstrates how to use the MotionClip Retime node to crop an animation and alter its playback speed.

See also

Geometry nodes