Re: [osg-users] zbuffer issue
Hi Christian, I really doubt you have a general z-buffer issue, but from the pictures is looks like you have problems with geometry that is overlapping that shouldn't be. Any chance that you are accidentally creating quads that overlap in your code? Robert. On Sun, Jun 14, 2009 at 11:06 PM, Christian Samosgfo...@tevs.eu wrote: Hi community, i noticed an annoying rendering problem in my application. my application is based on the osgforest example, with the difference that not every tree is represented with its own drawable, but many trees are merge into a handful of drawables, placed at a regular-grid. the rendering problem occurs only when i use real-world coordinates for the tree postions: e.g. 683006, 213213, 0. instead of localized equivalent of 6, 213, 0 and when using the approach described above. there are no problems when i use such large coordinates with one-drawable per tree, like in the original osgforest implementation. it happens when i zoom in very near, the trees (only the trees, not the terrain or anything else) begin to flicker and overlapped faces of the tree's double-quads gets revealed, while others gets hidden. after i zoom out, rendering problems stops. maybe some z-buffer resolution related issue? i hope i described it in a way you can imagine it. if not i can send the whole example/resources. btw. i'm using osg-2.8.0 best regards, christian -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=13967#13967 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] zbuffer issue
Hi, thanks for all the reply like colin noted, the render problem vanished as i stripped off the offsets which caused the large coordinates and work now with localized coordinates. if i ever need to display the real coordinates in an text-insert, i can re-add the stripped offset before display them. Thank you! Cheers, Christian -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=13990#13990 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] zbuffer issue
i forgot three things to mention: 1.) as i mentioned above, i place adjacent trees into one geometry. e.g. a geometries' vertex-array has numberOfAdjacentTrees*8 (=double quads ) entries. but i use only one primitiveSet to construct the geometry. i hope this is okay. geometry-addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, vertices-size())); 2.) the geometries aren't generated from back to front. 3.) the problem also occurs when i don't use blending, alphafunc or even textures. -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=13968#13968 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] zbuffer issue
Sorry, for another posting: i just tested the original one drawable per tree implementation with such large coordinates again and noticed that it also tends to flicker, as well hidden faces were revealed also. i couldn't encounter the outer mentioned problems. thanks in advance, christian -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=13970#13970 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
