Houdini 16.5 Crowd simulations

Crowd obstacles

How to set up obstacles for agents to avoid.

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You can specify static DOP objects for agents to avoid using a behavior. You can put this behavior before the behavior merge node

Setting up static DOP objects as obstacles

  1. Make the obstacle object a static object in the crowd simulation.

  2. Select the obstacle object. On the Crowds shelf tab, click Obstacle.

The shelf tool creates a POP Steer Obstacle node, sets it to avoid the static object, and wires it after the merge_states node.

Because the POP Steer Obstacle is after the merge_states node, it applies to all agents regardless of state. To make agents avoid an obstacle only in one state, move the POP Steer Obstacle node between the State node and the merge_states node. See the crowd simulation network and states and behaviors for more information.

Tips and tricks

  • Collisions and avoidance are calculated using the geometry bound to the character skeleton.

Crowd simulations

Getting started

The moving parts

  • Agents

    About agents, the moving "actors" that make up a crowd simulation.

  • States

    About agent states, the virtual "mood" of each agent which controls the agent’s animation and which behaviors it runs.

  • Clips

    How to associate animation with agents in certain states.

  • Triggers

    How to specify conditions that cause agents to change from one state to another.

Next steps

  • Foot planting

    How to set up agents to adapt their animation to terrain and prevent skating.

  • Transition graphs

  • Attributes

    Useful attributes for reading in triggers, or that you can set to affect behavior.

  • Sensors

    How to make agents behave differently based on their virtual senses.

  • Diversity

    How to create a more realistic crowd by making agents look and act differently.

  • Weights

    How the Houdini crowd solver decides which behaviors to apply to an agent at each time step.

  • Terrain

    How to specify terrain geometry for agents to walk across.

  • Obstacles

    How to set up obstacles for agents to avoid.

  • Dynamics interaction

    Tips on setting up interaction between agents and other types of dynamics.

  • Ragdoll simulation

  • Adding direction

    How to assert manual control over different aspects of the crowd simulation.

  • Fuzzy Logic

  • Caches

    Tips for efficiently caching and loading crowd sims.