Multitexturing Terrains

Blitz3D Forums/Blitz3D Programming/Multitexturing Terrains

From what I've worked out by playing with em, I can create a heightmap - then lightmap it..

I can then apply colour to the lightmap bitmap to give me a painted terrain.

I can apply a texture to the whole terrain.. but how about I want to use perhaps 2 or 3 different texture maps to the same terrain ?. (such as a mountain, and a grass texture)

The only way I can see I can do this is to apply each texture over the whole of the terrain, and then use black to mask out the areas I want to show through to the next texture.

But... that would mean the texture I use would have to stretch over my entire terrain - which is pretty huge.. giving me a poor giant pixel texture. If I tile it, then the same masked areas would appear in the wrong places over the terrain.

Any ideas, or advice please guys..