Elements of the scene

A Houdini scene consists of objects, such as geometry, characters, nulls, cameras, and lights. You can collect objects together into bundles so you can refer to them collectively, such as in a light mask (which specifies what lights illuminate a given object).

Geometry (such as props and character skins) lives inside a Geometry container object. The geometry inside a geometry container is created by surface nodes. Geometry has components such as points, faces, edges, and vertices. You can collect components into groups so you can move, edit, etc. a group of points or faces together Component groups are sometimes called clusters in other software.

Geometry can also have attributes. Attributes store arbitrary data on pieces of geometry or on components such as points. The data may be used by Houdini (such as the color and velocity attributes), and you can also use them in expressions. Attributes are sometimes called blind data in other software.

Objects, geometry, and other operations are represented by nodes in a network. Nodes store parameters, which are the options that control how each node works. For example, the Sphere surface node creates a sphere surface, and it has a parameter to control the radius of the sphere it creates.

• Lights and cameras