Houdini 20.0 Nodes Geometry nodes

MotionClip Update geometry node

Update a MotionClip using the given point list.

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Since 18.5

This SOP takes a list of points with time attributes, and inserts/removes/updates matching points within the MotionClip. Each point corresponds to the joint with matching name and time attributes.

If present, the localtransform attributes of the points are used when adding to or updating the clip. Otherwise they are estimated by substituting the world space transform into the clip’s evaluation at the given time, and computing the localtransforms of that skeleton.

The MotionClip Extract SOP outputs data in the format appropriate for this node. You can extract a set of points using the MotionClip Extract SOP, perform some manipulations, and use this node to write the changes back into the cache.

State

This viewport state allows you to visualize a MotionClip or its evaluated poses over time using a color ramp, and 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

Overlap Mode

Specifies the behavior when a point overlaps with an existing point within the MotionClip.

Override

Overrides the existing point’s attributes with the new point’s attributes.

Remove

Removes the matching point from the MotionClip.

Keep Existing Value

Leaves the original point values, changing nothing.

Override Range

Inserts new samples and overrides overlapping samples, as well as deletes any joints in the skeleton between the earliest and latest instances of the corresponding points in the second input. This allows the MotionClip to be updated without needing to exactly match the timing of the points (from the second input) with the poses in the MotionClip.

Tip

If the MotionClip Extract SOP Output Mode is set to Motion Trails, then you can use the Curve SOP to alter the motion trail before applying those changes to the MotionClip with the MotionClip Update SOP. In this case, the Override Range option allows the MotionClip to be updated by a curve (the output of the Curve SOP) without the exact times of the points on the curve.

New Mode

When Overlap Mode is not set to Override Range, this specifies the behavior when a point does not already exist within the MotionClip.

Insert New Sample

Adds the point into the sample at the given time, creating a new sample at that time if none exists.

Prefer Using Local Transforms

Determines whether to use the local or world space transformations when they are mismatched. When turned on, uses the localtransform attribute, if present.

Attributes

These parameters are used to determine the attributes from the input MotionClips that become animated on the updated poses of the output MotionClip.

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

Tip

To maintain the attributes that were previously animated without adding any additional attributes to the poses other than the attributes from the new joints, turn on Repack Attributes, clear Rest Attributes, and set Animated Attributes to *. These are the default parameter values.

Repack Attributes

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

Rest Attributes

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

Tip

When using the Point Attributes parameter to blend additional attributes into the MotionClip, include the same list of attributes from Point Attributes in this parameter. This ensures that the attributes are blended even if they did not exist on the animated poses.

Animated Attributes

The attributes that are evaluated from the animated poses of the MotionClip. All attributes that match this pattern remain animated on the output MotionClip.

Blend Joints

These parameters define what happens to a joint when it is overridden. The default behaviour is to override the existing joint’s attributes with the new joint’s attributes. If the joint is defined within a Joint Group, the transform attributes, as well as any attributes defined within Point Attributes, are blended based on the weight of that Joint Group.

Blend Joints

The set of joints that undergo blending - the Overridden Joints, New Joints, or both groups of joints.

Point Attributes

The point attributes of the joints that are blended, in addition to the P, transform, and localtransform attributes.

Weight Method

The method used to determine the weight of each point.

By Joint Group

The weight of each point is defined by the Weight parameter in this node.

By Attribute

The weight is taken from each point.

By Joint Group

These parameters are visible when Weight Method is set to By Joint Group.

Number of Joint Groups

The number of joint groups to search when a joint is replaced. If a joint belongs to multiple groups, it is blended based on the parameters of the first group to which it belongs.

Joint Group

A group of the reference joints to be blended.

Weight

The weight of the joints in this group when blending. A value of 0 weighs toward the original joint, and a value of 1 weighs toward the new joint.

By Attribute

These parameters are visible when Weight Method is set to By Attribute.

Weight Source

The set of points that the weight attribute is taken from.

Weight Attribute

The name of the weight attribute.

Inputs

MotionClip

The MotionClip to be adjusted.

Joint List

The points you wish to update. Each point corresponds to the joint on the skeleton with the matching name and time attributes.

Outputs

MotionClip

The MotionClip from the first input with the updated joints from the second input.

Examples

SimpleMotionClipUpdate Example for MotionClip Update geometry node

This example demonstrates how to use the MotionClip Update node to raise the shoulder joints of a motion clip.

See also

Geometry nodes