Option for a fixed environment just rotate model.
I'm making this request mostly to help viewing in the CAM workspace while simulating but it would also be useful in the render workspace. Lets face it in real life if you want to look at the bottom of part you're more likely to turn the part over rather than stand on your head or turn the whole world upside down!
Here's an example of a simulation in the CAM workspace, working on the bottom face.
Mark