Houdini 20.0 Nodes Geometry nodes

Crowd Source geometry node

Creates crowd agents to be used with the crowd solver.

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Since 14.0

This node is used as part of a crowd simulation workflow. By default it creates a group of agents randomly scattered on an area specified by the controls. If geometry is connected as input, it will scatter agents onto that surface. If the input geometry only contains points, an agent will be placed at each point position.

Parameters

Source

Input

Source of the agent geometry and rig.

Subnet

Asset node or a subnet in current session

Disk

The files are read from disk (need to be created using agent rop)

Object Subnet

Location of agent asset or subnet node when Input is Subnet.

Cache Directory

Location of agent files when Input is Disk.

Keep External References

Specifies whether the agent primitives should reference the agent definition files on disk. If enabled, saving agents to a geometry file will only store references to the agent definition files, instead of embedding the agent definition in the .bgeo or .geo file (which produces a self-contained, but larger, geometry file).

Reload

Reload the files/nodes being referenced (Houdini caches needed agent files; when they're updated reloading them is required).

Rig

These parameters are used to specify agent rig bones. These are used in various parts of the crowd workflow such as Terrain Adaptation or Agent Look At.

Clips

Rest Clip

Animation clip that has the agent in neutral rest pose (no animation). This is used as reference when modifying agent rig.

Setup

Layout

Shape pattern of the crowd agents created.

Random

Scatter randomly based on the number and area size.

Formation

Create a group based on rows and columns.

Area Size

Size of the area that will be used to scatter agents onto.

Number

Number of agents to create.

Random Seed

Used when randomly scattering agents.

Relax

Used to push the agents apart to prevent initial self collisions.

Density Attribute

Name of the attribute that stores density to be used for scattering agents.

Density Scale

Multiplier on the density attribute.

Force Total Count

Controls number of agents scattered using density attribute. When off number will be based on the density values; when on it will use value specified by the Number parameter.

Agent Name

Name of the agent (this name is also used when referencing animation clips).

Group Name

Name of the group that the agents will belong to.

Default State

Initial state that the agent will be when the simulation starts.

Color

Color of the agent points and wireframe bones.

Scale

Size of the agent (sets pscale attribute on the agent point).

Min Speed

Initial minimum speed for the agent (m/s). This may be adjusted during the simulation by the Animation Behavior settings on the Crowd Solver.

Max Speed

Initial maximum speed for the agent (m/s). This may be adjusted during the simulation by the Animation Behavior settings on the Crowd Solver.

Max Turn Rate

How fast the agent is allowed to turn when changing direction (deg/sec).

Max Force

Maximum force that is allowed to affect the agent (values higher are clamped).

Initial Velocity

Initial velocity of the agent.

Heading

Initial direction the agents face (if initial velocity given it will override this).

Up

Up vector to be used for the agents.

Randomize

These controls allow randomization of parameters per agent.

Randomize Agent Name

This will randomize the agent name.

Agent Name Prefix

Prefix part of the agent name. The variations will be created by appending random numbers based on the variations/seed parameters (agent1/agent3/agent8/etc).

Variations

Number of agents names to create.

Seed

Random seed value to be used when creating per agent names

Distribution

Type of distribution to be used when creating random values

Visualize

Display Layer

Specifies which layer of the agents is displayed. All agents have a 'default' layer which is the skin geometry being deformed. The 'collision' layer is created based on the capture regions of the bones used to deform the agent.

Inputs

Custom Surface/Points

Surface to be used as a base to scatter crowd agents onto. If only points are given, these will be used to create agents at each point position.

Outputs

Agents

Agent primitives to be used in crowd simulation.

See also

Geometry nodes