All right, we are making some progress here!
I'm still not quite sure after watching Whaat's skippy tutorial how to achieve blended materials other than clipped ones!
Yeah, this is a bit confusing especially if you want the blended materials to be textured. Here are the basic steps:
1) Create your Material A - Eg. Brick material with a bump map
2) Create your Material B - Eg. Water streaks material
3) Create a Blend material and set your Material A and B
4) Use the blend factor value to control the amount of material A and B. Eg. A value of 0.4 means 40% material A and 60% material B (I think)
5) Important step: You need to apply a texture to your Blend material using the Sketchup paint bucket. This is so the proper UV coordinates get exported to Indigo. In your case, you would apply a brick texture and position it accordingly with the Sketchup position texture tool.
6) The texture applied to the Blend material will be used as the clipping map UNLESS you choose "Disable material texture" in the SkIndigo settings. If you disable the texture, the clipping map is ignored and the materials are blended like a layered material. The texture will only be used to export the correct UV coordinates. I couldn't come up with a better way to do this. Hope it makes sense!
I guess there is just need for lots of trial and error, lots of trial and error!
The whole purpose of including the material presets was to help minimize trial and error for new users. Just choose a preset that is somewhat similar to your desired material properties. You shouldn't have to do much trial and error after that. Check out the material properties in the skippy tutorial to get a feel for what settings to use.
The only other question I have for now is what is the enable instancing when you right on a component?
Indigo supports internal mesh instancing. If you have a Sketchup component that is repeated several times, you might want to enable instancing for that component. Say you had a 1000 identical chairs in an auditorium model. If you enable instancing for the chair, the geometry will only get exported once. It cuts down export time and saves memory. It is a new feature so it might have some bugs...try it out!