[vtkusers] OS X Python Carbon Valid Pixel Format??

[Chris Scharver]

At 10:07 AM -0600 03/11/2003, Karl Garsha wrote:
>I'm using a Powerbook G3 Wallstreet (1998) with a Sonnet Cresendo 500Mhz G4 proc upgrade.  The Powerbook has an ATI RageLTPro chipset for graphics (4mb VRAM).  OS X historically did not support OpenGL (or Rave)  hardware acceleration for this graphics chip, although OS 10.2.4 (which I'm running) supposedly includes drivers for this graphics chip.     The specific error I'm getting follows:  >>> iren.Initialize()
>ERROR: In /Volumes/MANGO_STORAGE/vtk/VTK-4.2.1/Rendering/vtkCarbonRenderWindow.cxx, line 731
>vtkCarbonRenderWindow (0x13c1680): Could not find valid pixel format

vtkCarbonRenderWindow is currently indeed requesting that the pixel format is hardware accelerated. That may not be the single cause of your problem. It's requesting 32 bit color and depth buffers, and that's likely more than the ATI RageLTPro can handle with only 4MB. Thse use AGL_RGBA is supposed to grab the best available, but the request for a 32-bit depth is probably too much. If you're daring, you could modify your copy of VTK/Rendering/vtkCarbonRenderWindow.cxx and change the aglAttributes requested in vtkCarbonRenderWindow::CreateAWindow() to changes the values for AGL_DEPTH_SIZE and AGL_PIXEL_SIZE. If that doesn't work, you could remove the AGL_ACCELERATED attribute to give you the software renderer.

A more robust solution implemented directly within VTK would require more experience with AGL to repeatedly request pixel formats until the attempt succeeds.

Chris
--
Chris Scharver
Electronic Visualization Laboratory
The University of Illinois at Chicago
Ph: 312-996-3002   FAX: 312-413-7585
<http://www.evl.uic.edu/scharver/>