How to set up a crowd simulation

Crowd simulations usually consist of a particle system with instanced geometry (such as people or animals). A POP Network is set up to control the way the instanced geometry moves and interacts with each other in the scene.

• Start by creating a particle system using either the Source from Geometry or Emitter tool on the Create Particles shelf.

• Apply a directional force to the particles.

• Instance geometry onto the points.

• Control the behavior of particles when they collide with geometry using a Collision node.

• Use a Soft Limit particle node to create a boundary with spongy bounces. This POP provides smoother, less jerky bounces than the Limit and Collision POPs.

• Add an Interact node to make the particles attract or repel each other.

• Set the velocity of the particles with a Velocity particle node.

• Insert a Speed Limit particle node to set a minimum and maximum velocity for the particles.

• Apply some drag to the velocity of the particles by using the Drag tool.

• Add an Attractor node to attract or repel the particles toward/away from a force defined by a Force SOP (for metaballs) or the Force tab of a Point SOP (for other geometry types).

This example shows a particle simulation with toy mice instanced onto the points.