Nodes are the basis of everything that Houdini does. When you create geometry, rig a character, and so on, Houdini is creating nodes behind the scenes. The nodes record the actions you took and the parameters you used. You can go “back in time” and change parameters and selections of existing nodes to edit the history of how your scene was created.
Node types
 | Channel nodes | |
 | Compositing nodes | |
 | Dynamics nodes | |
| Generic tools | ||
 | Object nodes | |
 | Particle nodes | |
 | Render nodes | |
 | Shader nodes | |
 | Surface nodes | Nodes that control the shape of geometry. |
| Surface tools | ||
 | VEX networks | Containers for VOP networks. |
| VEX nodes |