Poser 7 has a render passes script in the script menu in the RenderControl folder. It outputs an occlusion render pass, an ambient render pass, and shadow render passes for each light.
Obviously, it will only render out a pass from the view of the camera, however, using an orthogonal view you could use the occlusion render for dirtying up a texture map as in Stonemason's tutorial (linked in the above posts).