Changing color on contact?

I hope this is the right forum…I’m new to blender artists (and blender…) I’m working on a project where I’m trying to illustrate friction on a microscopic level. I currently have two landscapes generated by ANT Landscape, one facing up the other 180 degrees about the X axis facing down. One ‘landscape’ moves across the other, and I want to show that when two asperities (mountain peaks) contact, it changes color (from gray to red or something)…

Any ideas where to start?

Depending on the actual effect you are wanting, you could look at using the dynamic paint features https://docs.blender.org/manual/es/dev/physics/dynamic_paint/index.html

Look at https://www.google.com/search?q=blender+dyniamic+paint&oq=blender+dyniamic+paint&aqs=chrome..69i57.7495j0j7&sourceid=chrome&ie=UTF-8#q=blender+dynamic+paint+tutorial&safe=off&tbm=vid

It sort of worked, but it’s not perfect yet. I’ll keep working on it, thanks!

Just wanted to update…

So, I figured it out a while ago, but I’ve been playing with it for a while. I ended up using dynamic paint to change the color, had to bake out the UV map and apply it as an image texture (since I’m using cycles render) and it worked beautifully. just cleaning things up and trying to grasp it all now. Thank you for the help Richard!

I know I’m very new to all of this, but I’m finally figuring out how to…well…figure these things out! It’s been a heck of a ride so far.