Hans,

many thanks again for the immediate feedback. Indeed, I can confirm that rendering a photo with Q3 or Q4 produces a correct output, whereas Q1 or Q2 produce the ceilings with gaps.

See e.g. http://netcup.bokomoko.de/~rd/sweethome ... efact4.png

Are Q3 and Q4 using sunflow? Do you know through which mechanisms or libraries the HW is accessed in Q1 or Q2? Java 3D?

Are you using java6 ? I have here

I read now through the FAQ, but did not find anything I could relate to my issue....did you have anything specific in mind?

Thanks
Rainer