Crowd simulations

How to create and simulate crowds of characters in Houdini.

Subtopics

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.
Triggers

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

Tips for efficiently caching and loading crowd sims.

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.
Weights

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

Diversity

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

You can add and constrain vellum cloth as part of agent shape geometry, and then simulate the cloth based on agent movements.

Foot planting

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

How to specify terrain geometry for agents to walk across.
Obstacles

How to set up obstacles for agents to avoid.

What’s new in Houdini 17

New features and changes in Houdini 17.
Basics

The basics of working with Houdini’s user interface.
Shelf tools

How to use and customize the icons on the shelf at the top of the main window.
Networks and parameters

How to use the network and parameter editors to work in Houdini.
Examples

Example files showing how different nodes work.
How to use the help

How to use the online help and document your own tools.

Geometry

How Houdini represents geometry and how to create and edit it.
Copying and instancing

How to use copies (real geometry) and instances (loaded or created at render time).
Animation

How to create and keyframe animation in Houdini.
Character

How to rig and animate characters in Houdini.
Rendering

How to render images and animation from the 3D scene.
Materials

How to assign materials and create custom materials for shading.
Compositing

Houdini’s compositing networks let you create and manipulate images such as renders.
Digital assets

Digital assets let you create reusable nodes and tools from existing networks.
Import and export

How to get scene, object, and other data in and out of Houdini.
MPlay viewer

Using Houdini’s stand-alone image viewer.

OBJ - Object nodes

Object nodes represent objects in the scene, such as character parts, geometry objects, lights, cameras, and so on.
SOP - Geometry nodes

Geometry nodes live inside Geo objects and generate geometry.
DOP - Dynamics nodes

Dynamics nodes set up the conditions and rules for dynamics simulations.
VOP - Shader nodes

VOP nodes let you define a program (such as a shader) by connecting nodes together. Houdini then compiles the node network into executable VEX code.
ROP - Render nodes

Render nodes either render the scene or set up render dependency networks.
CHOP - Channel nodes

Channel nodes create, filter, and manipulate channel data.
COP2 - Compositing nodes

Composite nodes create, filter, and manipulate image data.

Menus

Explains each of the items in the main menus.
Viewers

Viewer pane types.
Panes

Documents the options in various panes.
Windows

Documents the options in various user interface windows.
Stand-alone utilities

Houdini includes a large number of useful command-line utility programs.
Python Scripting

How to script Houdini using Python and the Houdini Object Model.
Expression functions

Expression functions let you compute the value of parameters.
HScript commands

HScript is Houdini’s legacy scripting language.
VEX

VEX is a high-performance expression language used in many places in Houdini, such as writing shaders.
Properties

Properties let you set up flexible and powerful hierarchies of rendering, shading, lighting, and camera parameters.
Python Panels

You can script custom pane types using Python to create your own UIs.
Galleries

Pre-made materials included with Houdini.