I'm guessing that this is an old computer graphics problem to do with depth sorting the drawing sequence of transparent objects, but I'm a bit puzzled why OSG is having a problem with this little example.
Basically, in some views of a this example scene, the transparency is not working properly. See attached JPG screen grab and OSG model. I suspect the root cause that in some views, the depthsort is causing a door to be drawn before a shelf even though the door is nearer. Is the depthsort ordered by depth of the midpoint of geometries? That would certainly explain the issue because the midpoint of a shelf could certainly be infront of the midpoint of a door even though ALL of the door polys are infront of ALL the shelf polys. (yes, read that last sentence again! lol.) I was wondering if the depthsorting algorithm could be improved to fix this problem, maybe by sorting by deepest geometry vertex rather than geometry midpoint (if that's what it's doing) ? Is there way to override render bin depthsort to provide it with different depth values for each geometry/drawable? I know I can also tweak things for special cases e.g. by putting the door and shelf in different render bins but that's not a general or practical solution. How are others solving this problem? Regards. Chris D. ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=25040#25040 Attachments: http://forum.openscenegraph.org//files/glassproblem_994.osg http://forum.openscenegraph.org//files/glassproblem_137.jpg _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
