Interesting idea. I'm not a lighting expert, but after a bit of experimentation: Setting the ambient to white does make an object "glow". If it has a texture, that texture will also show up; if no texture, the main color is irrelevant and the object is just flat white, sort of empty-looking. In this image, both balls have white ambient. The left ball actually has a dark blue main color, but the white ambient wipes it out. The right ball has a random orange-ish texture applied, which shows up equally well with lights gone. So, an easy Python solution might go like this: 1. Give the selected object a white ambient. 2. If it has a texture, leave that in place. 3. If it doesn't own a texture, turn its main color into a temporary texture BMP and apply that tex. This would not make any highlights or reflections; the object would be diffusely lit (matte) from all views. I don't see any way to set up highlights and reflections without, as Rodzilla says, digging into Poser's underlying render code.
My python page
My ShareCG freebies