I started by using a primitive "Plane" as the ground. I textured it with a diffuse shader for grass, and a particles/multiply shader for random splotchiness to distract from the grass tiling. It looks like this: http://dl.dropbox.com/u/6927019/ground1.png
This is good so far, except I want the ground to be more subdivided so I can adjust height by changing vertices. Since there is no way to specify that in Unity for the Plane primitive, I create one in Lightwave 3D, convert it to fbx (just like all my other 3D assets), and use that instead.
However, the particles/multiply shader on the fbx results in a black mesh instead of shading it as expected. THE QUESION: Why would the shader work on the primitive but not on the fbx?
I know that the fbx has UV coordinates because the diffuse shader works properly on it.