My problem is how to get three or more textures onto a single mesh. I'm trying to minimize mesh and texture sizes so three terrains is not an option. I can use two textures such as grass and gravel. I can create another texture like an alpha mask to draw roads across the surface. This will work the same as using a grayscale in the B channel to control the A and C blending in bryce. I'm just wondering if anyone has used a program like deep paint that might do this on the fly with tools like an airbrush.