How can I get or set textures on a material other than the main texture? (eg, the bump map)

Questions & Answers
1

I can't figure what is the name of this component, so I'll try to describe it somehow.

When selecting a mesh in the inspector, there are 2 textures displayed. One texture is accessible trough 

Texture2D tex = renderer.material.GetTexture("_MainTex") as Texture2D;

How can I accesses the other texture?

Thanks.

2

Different shaders which have multiple textures will have an internal variable name for each texture. As you've shown, the common name for the main diffuse texture is "_MainTex", and some other names used in some of Unity's built in shaders are:

  • "_BumpMap" (the normal map in bumpmapped shaders)
  • "_Cube" (the reflection cubemap in reflective shaders)
  • "_DecalTex" (for the decal shader)
  • "_Detail" (for a shader which allows detail maps)
  • "_ParallaxMap" (for parallax mapped shaders)

You can also access the "_MainTex" more conveniently by using the .mainTexture property of the Material class like this:

Texture2D tex = renderer.material.mainTexture;