Introduction to Crowds in Houdini

Download Houdini File: Crowds Intro Simple Crowds SIM.hiplc

The Crowd tools in Houdini is optimized very well. The 3D animated characters used in the Crowd system are known as Crowd Agents in Houdini. Houdini bakes the animations and a name is assigned to the animation for the corresponding agent. This makes it easy to attach several animations to one rigged character.

Crowd Agents in Houdini

Crowd Scene with 850 Agents

Packed Geometry

Crowds cooks pretty fast considering the amount of data going through the Crowd Solver. Imagine a scene full of characters walking around the streets. Let’s say 100 people? 200 people? I have tried simulating over 1000 people in a crowd simulation with 1000 frames in less than 20 minutes.

Houdini bakes the 3D animation of the character and compresses the whole character into Houdini’s famous packed geometry for optimal memory and computational performance. All this under the hood using the Agent nodes.

Built-in 3D Animated Characters in Houdini

Walking Mocap Animation in Houdini

It gets better! Houdini even has build-in animated characters that are fully rigged and ready to be used for Crowd simulations. This makes it very convenient for those that just want to test out the tool or learning the system. With a click of a button you have a list of animations available and when you’re just testing something simple, this fast-tracks the workflow because you don’t have to worry about finding an animation and cleaning up the motion capture.