HeightField geometry data driving shader?


Hello gents,

I am a texture artist/3D generalist eagerly diving into Houdini for the first time (while using it in a production, as it happens).

My question:

So I have a piece of terrain generated by the new Height Field nodes (see attached image). Lovely.

What I want, is for the mask data (the red in the 3D viewport is an example of one of the masks based on height) to drive the shader live, not through a static exported image file. As I see this problem, how do I cross that divide (from the SOP (I guess) world to the SHOP (or is it VOP) world?

One suggestion I have received was to use the Attribute Promote node, to sort of flag the data I want on the geometry side, and using a Bind node on the shader side to bring that data into the shader. In reality I haven’t managed to make it work. There are around 18 different attributes on the bottom most nodes - which one to flag? Or is it a data conversion type problem perhaps (trying to fit a round peg into a square hole)? Or do I need to bake the HeightField into actual geometry first perhaps? Or am I looking at this the wrong way around?

I sincerely hope you can help…