Well, it took a little bit for my post to be approved and in that time, I was able to get a similar result by blending Brick Generators and using a gradient map. Thanks anywhoo!
Very inspiring works! I've never been a big fan of Tomb Raider until the reboot, the game rocks! Thanks for posting this. Are the dense geometry used for vertex blending?
paint with just the red channel and drag the value slider to the left. also your going to want to do more with teh shader to get a better blend transition at somepoint.
Good progress! the nostrils seem a bit too lumpy in my opinion, they could be blended in more towards the tip of the nose. The jawline might be a bit too sharp too.
Hot damn, this is nice. Just about the only issue I can see is that the grass cards aren't blending with the ground very well, especially apparent in that last image.
If you need to paint on pieces that are very close together, switch your brush alignment setting to UV, this will paint in UV space and will not bleed over the other pieces of geometry.
You can use masks or vertex blending, both has advantages and disadvantages and there are a lot of tutorials around. This one is the first to come to mind. http://www.hourences.com/book/tutorialstextureblending.htm
The blend map is called a Splat Map. Have you tried searching with this term? I would try variations on "unreal splat export" or "unreal landscape texture export".