Well I´ve solved the problem with the sky-3D-actor (http://forum.dead-code.org/index.php?topic=3421.0
The problem was that it wasn´t lit up properly, causing verys strange black patches on the sky actor
So that´s why I come up with my feature request.
Would it be possible to add something like
actor.ambientlight = makeRGB(r,g,b,a)
so that a specific actor has a "global" light, but doesn´t affect the other 3D actors.
That would be very useful, because I could use that to light up the sky actor, without affecting the other 3D actors.