Metal that's only rusted in places. Is it possible to drive?

[cigoler]

Can someone give me some pointers please.

If I want to have a metal material (for example) that is clean in some areas, and rusted in others, how can I drive that in Houdini / Octane? Is it possible?

[mlmcgoogan]

Couple of ways to do this. Here's a simple one:

• - Setup two material nodes - one for your clean metal, one for your rusted metal.
  - Plug them both into a material mixer node.
  - Plug one of Octane's procedural textures into the amount input of the Material Mixer.
  - Voila

For the procedural texture you could for instance use Procedural Noise to blend rust in throughout the surface or use Procedural Dirt to bring rust in around features/corners in the mesh. Best bet is usually a combination of both via a Texture Multiply node.