From: Kent E. <esc...@ps...> - 2006-12-19 22:42:18
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mesaBugFrame16.png
mesaBugFrame18.png
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We are seeing a rendering error where some polygons just disappear at certain viewing angles. - ParaView 2.4.4 (compiled to use only 1 CPU) - Mesa 6.4.2 using "linux" configuration - 16 Itanium2 IA-64 1.3 GHz dual core nodes (32 CPUs total) - 3 Gb memory - Suse SLES8 - viewing surface of data from VTK file with cell type VTK_TETRA I used ParaView to make a short MPEG movie. As the object is rotated pieces of the top surface disappear then return. Two frames of the movie are attached. The whole movie is available via anonymous ftp at ftp.psc.edu under pub/outgoing/eschenbe/Mesa The VTK file displays fine elsewhere. Built-in objects (sphere, cylinder, etc.) look fine. I also tried a half-dozen of the demos that came with Mesa and saw no problems. I cannot reproduce the problem using parallel projection. The problem is seen with both standalone paraview and when running the server on that system with composition on (i.e., rendering via Mesa). Using the server with composition off (i.e., rendering on the client workstation using its graphics card) shows no problems. Thus it seems like this might be a Mesa problem. I'd be interested in any ideas or further tests. TIA! Kent Pittsburgh Supercomputing Center |
From: Brian P. <bri...@tu...> - 2006-12-21 16:15:55
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Kent Eschenberg wrote: > We are seeing a rendering error where some polygons just disappear at certain viewing angles. > > - ParaView 2.4.4 (compiled to use only 1 CPU) > - Mesa 6.4.2 using "linux" configuration > - 16 Itanium2 IA-64 1.3 GHz dual core nodes (32 CPUs total) > - 3 Gb memory > - Suse SLES8 > - viewing surface of data from VTK file with cell type VTK_TETRA > > I used ParaView to make a short MPEG movie. As the object is rotated pieces of the top surface disappear then return. Two frames of the movie are attached. The whole movie is available via anonymous ftp at ftp.psc.edu under > > pub/outgoing/eschenbe/Mesa > > The VTK file displays fine elsewhere. Built-in objects (sphere, cylinder, etc.) look fine. I also tried a half-dozen of the demos that came with Mesa and saw no problems. I cannot reproduce the problem using parallel projection. > > The problem is seen with both standalone paraview and when running the server on that system with composition on (i.e., rendering via Mesa). Using the server with composition off (i.e., rendering on the client workstation using its graphics card) shows > no problems. Thus it seems like this might be a Mesa problem. > > I'd be interested in any ideas or further tests. TIA! It looks like the "missing" triangles are actually there, just very dark. The pixels in that region aren't (0,0,0). Or perhaps we're seeing the back faces of triangles from the other side of the surface. You might try a newer version of Mesa (6.5.2 is the latest). Otherwise, please file a bug report and I'll look into it next year. -Brian |