[vtkusers] No GPU-acceleration with VTKEdge?

[Paul Melis]

Hello,

I'm trying to get VTKEdge to work, specifically the GPU-assisted volume 
rendering. I'm using an updated VTK CVS checkout as well as up-to-date 
SVN checkout of VTKEdge (both latest revision available yesterday). The 
machine I test on has a Quadro FX4000, which has an NV40GL chipset, 
which should be enough to satisfy the Geforce6 or higher requirement for 
the volume mapper. The driver used is 169.07 and the card has 256Mb memory.

The problem is that the VTKEdgeGPURenderDemo does not seem to use 
GPU-rendering. When run with the vase_4comp.vtk dataset I can see the 
CPU-load of both CPUs in the box go up to 100% and the normal coarse 
rendering is used during interaction, followed by a high-quality 
rendering after a few seconds when done with interaction. I.e. I don't 
see any difference with the normal software VTK ray caster.

The VTKEdgeGPUArrayCalculatorDemo demo prints error messages when run:

ERROR: In /home/paul/c/VTK-cvs/Rendering/vtkFrameBufferObject.cxx, line 160
vtkFrameBufferObject (0xa1e6288): Frame buffer object was not 
initialized correctly.

framebuffer is unsupported
Current framebuffer is bind to framebuffer object 1
color attachement 0:
 this attachment is a texture with name: 1
 its mipmap level is: 0
 this is not a cube map texture.
 this is not 3D texture.
color attachement 1:
 this attachment is empty
color attachement 2:
 this attachment is empty
color attachement 3:
 this attachment is empty
color attachement 4:
 this attachment is empty
color attachement 5:
 this attachment is empty
color attachement 6:
 this attachment is empty
color attachement 7:
 this attachment is empty
depth attachement :
 this attachment is empty
stencil attachement :
 this attachment is empty
ERROR: In /home/paul/c/VTK-cvs/Rendering/vtkFrameBufferObject.cxx, line 160
vtkFrameBufferObject (0xa1e6288): Frame buffer object was not 
initialized correctly.

I could not find a list of needed OpenGL extensions for VTKEdge, but 
glxinfo reports that GL_EXT_framebuffer_object is supported.

Any clues?

Thanks,
Paul