I'm not sure how Poser's render engine is set up, so I can't say for sure that turning the body to inivisible will improve times Deleting part of the body: I do this as an OBJ export of the selected body parts. Not clear to me if poser will let you save the truncated figure as a *.pz3; it clearly allows you to replace body parts with props and save that way-- but total deletion is escaping me at the moment, maybe someone else will chime in. Poser definitely exports an Alpha, if you save as Tiff. The alpha channel is very useful in compositing. Not dependant on background color-- it reflects the Z-order (distance from the camera) of the objects in the scene.