Oh, they changed the material.
//action: fx_terraintex
//title: Multi-Texture Terrain
//
//desc:
/// Supports an arbitrary number of 32 bit skins
/// RGB contains the tiled texture
/// Alpha contains the texture mask
Now add your textures (as skins) to your terrain, f.i. grass, rock, dirt, and create their masks on their respective alpha channels.
For a start, take a grass texture, paint the alpha channel opaque (/white), cut out a circle. Repeat this process and cut out another form from its alpha channel. Import these textures as individual skins, save, attach the function to your terrain, build and run. Now you will see the results immediately, I guess texture number one is below number two (and so on).
