Can we use a terrain-style splat shader on custom ground geometry?

We’re well under way on our first Unity-based project. The ground is already built in Maya (and will continue to see some edits), so for this project we cannot use the Unity terrain system. Still, we are hoping to find a way to use a single texture to define some good terrain texture blending, specifically to use RGBK values to combine four diffuse/detail shaders, and if possible to add an alpha channel to define some black as necessary. I see a lot of discussion of splat shaders here, but i’m new to Unity and most of what i see predates version 3.4 and the rest is over my new-to-unity head… i could use some solid info to share with the engineers so i don’t waste their time if we need something written here. Any thoughts?

If you look the the downloadable builtin_shaders->Terrain->Splats folder, AddPass is what Unity uses. It does the obvious thing, and is short. They use rgba for 4 textures.

The trick is to set it up – control texture stretched over the whole thing, splats scaled the way you want. And to get a good way to paint the control texture. That stuff is hidden in the Terrain script, but isn’t too bad.