2 Replies Latest reply on May 30, 2014 3:57 PM by eodabash

    Problem with OpenGL double precision geometry on Radeon HD 7*

    eodabash

      We're rendering geometry with double precision vertex attributes (ARB_vertex_attrib_64bit + ARB_gpu_shader_fp64 stuff). and we're running into a problem only on Radeon cards when drawing two meshes from different vertex buffers, where the second one always looks like garbage. It looks like it might be using vertices from the first object. If we switch from vertex buffers to client vertex arrays (i.e. passing real pointers to glVertexAttrib*Pointer) then everything looks fine. We've been testing on HD 7* cards with Catalyst 13.12 drivers as well as the 14.3 beta on Windows 8 64-bit. Everything looks fine on Nvidia and Intel.

       

      The screenshots below show the incorrect and correct images:

       

      bad.pnggood.png

       

      I haven't been able to reproduce the problem in a simple test case but the link below is to a VS 2013 (32-bit) binary that shows the problem immediately. The Debug -> Slot 1 menu option will toggle between the two modes (client pointers &. vertex buffers).

       

      https://dl.dropboxusercontent.com/u/69927239/partviewer_dp.zip

       

      You may need to install the VS 2013 runtime here in order to run it: Download Visual C++ Redistributable Packages for Visual Studio 2013 from Official Microsoft Download Center