Houdini 20.0 Nodes Dynamics nodes

Agent Clip Layer dynamics node

Layers additional animation clips onto an agent.

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Since 16.0

This node layers additional animation clips on top of the agent’s base animation clip. The clips can be applied to a subset of the agent’s skeleton. This is useful for introducing variations into a crowd shot, such as adding clips with upper body motion on top of a walk cycle. Multiple Agent Clip Layer DOPs can be wired together to create several layers.

Parameters

Group

Only affect a group of agents out of all the agents in the state.

Layer

Blend Mode

Specifies the blend mode to use for the layer.

Interpolate

Interpolates between the base pose and the clip’s pose according to the Blend Ratio.

Additive

Applies a percentage of the clip’s rotations and translations to the base pose, as specified by the Blend Ratio. Typically the layered clip is a difference clip, where the channels contain the difference from a reference pose rather than the actual pose. This is useful for adding additional variation while preserving the characteristics of the base animation.

Clips

The number of clips in the layer.

Randomize Clips

When turned on, randomly selects a clip from a custom distribution of clip names and weights.

Random Seed

When Randomize Clips is turned on, this seed is used when randomly selecting clips.

Clip Groups

When Randomize Clips is turned on, this is the number of groups of clips in the custom distribution.

Clip Names

A string pattern that specifies one or more clip names. The pattern follows the same syntax as the match VEX function. The Weight value for the group is divided evenly between the matching clips.

Weight

Specifies how likely the clips are to be selected.

Clip Name

The name of an animation clip.

Transform Group

The name of a transform group, which specifies a subset of the transforms in the agent’s rig that the clip is applied to. Transform groups can be created using the Agent Transform Group SOP.

Note

If this group contains the __locomotion__ joint, and the agent state’s Type is set to Locomotive, the Crowd Solver will blend the locomotion data from this clip when driving the agent.

Blend Ratio

Specifies how to blend between this clip and the base layer. When Blend Mode is set to Interpolate, a value of 0 has no effect, and a value of 1 completely overrides the base layer. When Blend Mode is set to Additive, Blend Ratio specifies the percentage of the clip’s rotations that are added to the base layer.

Weight

When there are multiple Clips in the layer, this specifies the weight used when blending between each clip.

Activate with Trigger

When turned on, starts playing back the clip when the specified input crowd trigger becomes active.

Play Once

When turned on, the clip is played through once, instead of repeating until the trigger is released. This parameter is available when Activate with Trigger is turned on.

Blend In Frames

When Activate with Trigger is turned on, and the trigger is activated, the clip is blended in over the specified number of frames.

Blend Out Frames

When Activate with Trigger is turned on, and the trigger is released, the clip is blended out over the specified number of frames.

Initial Clip Time

When turned on, overrides the initial clip time for the animation clip, and sets the initial clip time (in seconds) for all agents in this state. When turned off, the initial clip time is inherited from the state’s base animation clip.

Random Clip Offset

When Initial Clip Time is turned on, this randomly shifts the initial clip time forward for each agent by up to the specified number of seconds.

Random Seed

When Random Clip Offset is turned on, this seed is used when randomly varying clip times.

Clip Speed Multiplier

When turned on, specifies a multiplier for how fast the animation clip is played back. When turned off, the clip speed is inherited from the state’s base animation clip.

Locomotion Speed Multiplier

When Clip Speed Multiplier is turned on, this is a multiplier for how fast the locomotion channel of the animation clip is played back.

Variance (%)

The percentage that the Clip Speed Multiplier can be randomly increased or decreased by. For example, if the Clip Speed Multiplier is 0.7 and the Variance is 10%, the agents' clip speed multipliers will be random values between 0.63 and 0.77.

Random Seed

When Variance is turned on, this seed is used when randomly varying clip speeds.

Use VEXpressions

When turned on, uses a local expression to override the parameters related to the clip speed multiplier or initial clip time for a specific clip, as well as the blend ratio and weight for the clips. Select Pass Through from the drop-down menu on the right to see the variables that you can modify.

Use VEXpressions

When turned on, uses a local expression to modify the array of blend ratios and weights. Select Pass Through from the drop-down menu on the right to see the variables that you can modify.

Bindings

Geometry

The name of the simulation data to apply the POP node to. This commonly is Geometry, but POP Networks can be designed to apply to different geometry if desired.

Evaluation Node Path

For nodes with local expressions, this controls where ch() style expressions in VEX are evaluated with respect to. By making this ., you can ensure relative references work. It is important to promote this if you are embedding a node inside an HDA if you are also exporting the local expressions.

Examples

ClipLayerTrigger Example for Agent Clip Layer dynamics node

This example demonstrates how to use the Agent Clip Layer DOP to apply a clip to the upper body of an agent. The clip is activated when the agent is inside a bounding box.

See also

Dynamics nodes