Houdini Crowds Sink
Gait and agent speed
The gait speed controls how the clip is retimed based on the particle speed, but if Limit Particle Speed to Gait Speed Range is enabled it is also used to set speed limits on the agent's particle.
The 'steerforce' and 'steerweight' attributes accumulate a weighted average of different forces, which the POP Steer Solver (inside the crowd solver) uses to set the 'force' attribute
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For an in-place animation clip, the gait speed indicates how fast the agent was moving in the animation clip (think of it like the speed of a treadmill that the agent is on). The clip speed can then be adjusted based on the ratio between the particle speed and the gait speed to speed up or slow down the clip accordingly and avoid foot sliding.
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If the speed limits are enabled, the min speed is (1 - variance/100) * gait speed, and the max speed is (1 + variance / 100) * gait speed
Agents from KineFX
Agents are assumed to be skeleton based, the rest rides on top of that. So the workflow is
- Make a skeleton
- Convert to an agent with agentFromRig
- Add your animation with a motionClip and agentClip
- Add your skin with agentLayer
You might assume that once you've got a final kinefx bone deformed thing or packed character you'd just pipe that into an agent, but no, you essentially recreate it again but in an agent context.
Links
Agent Primitives: Geometry
00:01 - Intro to shapes, deformers, and layers
06:56 - Demo of Agent Layer 2.0 and Crowd Assign Layers
23:02 - Deformers and rigid shape bindings
27:25 - Bounding boxes
30:59 - Vellum workflow
Rapid Crowd Generation in Houdini 20 (+Agents in USD)
Attaching Props using layers and Solaris solution, Time Dependency Optimization, Motion paths (simulation-free) with triggers and avoids
A few notes on Houdini Crowd Simulations
KineFX Crowds
0:00:43 Intro
0:01:42 Motionclip basics
0:13:49 Blending Clips
0:22:29 Agent Promotion