Is there a problem having a negative y scale? I do that to get a left-handed system. Is there a better way to accomplish this?
It changes the winding order of your polygons, which affects face culling. If your model assumes face culling is performed based on a certain winding order, and you change that winding order with a negative scale, then I guess I'd expect to see the wrong faces culled, resulting in unlit surfaces being visible -- a lot like the odd behavior that you're experiencing.
If it is a problem having the negative y, shouldn't toggling 'b' always return it to the all-black rendering?
I'm not sure what 'b' does. I've noticed it appears to assume a certain initial state. If your model's initial state doesn't conform to the StateHandler's expectations, then you see some funniness the first few times you toggle.
To answer all of these questions in-depth, I'd advise you to cull your model down to one or two simple triangles that reproduce the problem. I don't think you can hope to understand what's going on until you have a really good understanding of your geometry and how it behaves in the presence or absence of negative scales.
-Paul _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
