I believe importing an object from Lightwave should preserve fidelity, unless it's a limitation of the poly count in the geometry export. If you're importing to Terragen as LWO, perhaps the normals are not preserved and object smoothing doesn't work (or it is due to the limitation of geometry in a single LWO object file). I would suggest using OBJ. If you're already importing as OBJ, then it could be an issue with the OBJ formatting and the PoseRay suggestion from Dune could help.
- Oshyan