PCZSM not handling transparency properly


20-02-2009 01:01:53

After discussion in this topic:
http://www.ogre3d.org/forums/viewtopic. ... 2&p=329473
I came to the conclusion the problem I was having was an issue related to PCZSM. I've drawn a transparent plane right over the portal. I noticed that after properly disabling the depth buffer writing to the transparent object, the portal plane was correctly being blended with the skycube, but the objects in the other zone (in the other side of the plane), were being drawn over the plane, with no blending. Since Ogre should draw transparent objects last, and that clearly wasn't the case, I assume that it was being done in a per zone basis:

All the opaque objects in the camera zone are drawn, then all the transparent objects of this zone are drawn. Then the same thing with each visible zone. This is the best explanation I could find to my problem, and it is not the expected behavior. The expected effect would be achieved if the opaque objects (depth_write on) from all the visible zones were drawn first, then the transparent objects (depth_write off) from the all visible zones were drawn last.


21-02-2009 05:12:35

You may be correct. (however, that other thread you linked to does not illustrate this problem... IMO, they are dealing with inverted polys in that case).. I will put this on the "possible bug" list...



21-02-2009 15:24:47

Hmm.. I'm using transparency objects in my scenes without any issues. They are rendered in the right order. Infact, the order sorting is done in the render queue. AFAIK, PCZSM doesn't touch those part. I think your problem is something else. Some screenshots would help. :)