A little OT here but Render To Texture can't render opacity, if that's what you're trying to do. To make tree foliage maps, I recommend modeling a fully leaved branch, then using RTT to bake that to diffuse and alpha.
Thats what im trying to do in 3Ds right now, more or less. I made the opacity map in Photoshop and switched my diffuse texture on my leaves with it in 3Ds, but im having trouble rendering it out. Most of the time it just ends up completely invisible/white. Im using RTT, but if i try using the normal viewport render it…