This started out as an experiment in using Bryce4's import features to bring models in from trueSpace so I could set them against a suitable background.
Unfortunately, Bryce4 can't handle a situation where a Boolean operation has left a concavity! Apparently the trueSpace file format puts a polygon over the hole, and Bryce can't tell it's different. UV mapped bitmap textures are a non-starter as well. I had to rebuild the Adamski UFO from basics to make it work, and the Nautilus model suffered from similar problems (which is why the Bryce stills are of it on the surface).
...although I'm willing to be proved wrong...
Still, using the two programs together like this is very useful in setting off my models against an interesting background. See also the two Nautilus stills "On the Surface" and "Underway".