custom hdri?

[dgud]

You can't currently change the background image, I have prepared for it so in a future release hopefully.

Ambient light adds (weak) light to all areas even stuff not lit by any other lights.

Ambient occlusion shadows areas in creases.
Areas that are shadowed by nearby faces if that explains it.

Would be nice to able to add that in the drawing area in realtime some SSAO algorithm,
but that requires that the rendering code is re-written again and preferable a higher OpenGL version
than what we require today.