To blend 3 textures together the TGLMultiMaterialShader can be used. An example where you might want to blend 3 textures is displaying detail on a terrain. One texture might be the main texture that is an aerial photograph that covers the entire terrain. The second texture might be the level of creeks and boulders and the third might be at the level of stones on the ground. This can be achieved by modifying the CVS demo called multimaterial under the directory material. The multimaterial shader will blend all of the texture in the TGLMaterialLibrary that are assigned to the material shader. You can modifiy the demo so that the texture main texture is applied to the terrain. The first texture can be the aerial photograph (instead of glscene.bmp). The second can be a detail texture that has creeks and boulders. You would increase the texture scale. The 3rd texture can be a detail texture for stones (instead of the specular texture) with an even greater texture scale.

Skinhat