You can export camera-dependent geometry using the LWO micro exporter. Searches on the forums should bring you some info on its use. You could also do textures by simply disabling all non-terrain elements from rendering, though this would be textures with the lighting intact. If you wanted "neutral" texture's you'd have to setup neutral lighting. Using exported geometry you can comp against a render from TG2 and do shadow casting, etc. I think that would be the preferred method, if available in your workflow.
- Oshyan