OpenGL Problems and Solutions Page
by Problem Description:
- Second Opened View has Graphic Defects
Description: This problem has been reported by users of Intel GMA-based display systems. The GMA chipset is a low-end chipset often used in laptops or in inexpensive desktop systems. It may support one OpenGL View just fine (or may have polygon shading defects in the first view), and a second View opened by WCS/VNS may lack texturing, may have polygon shading issues, or may not display at all.
Defective display on Intel chipsets. Bad shading on left, Bad shading and texturing on right.
Proper display on non-Intel (here, NVidia) chipsets.Affected cards:
- Intel GMA (via Wikipedia) chipsets
Workarounds: None. problems may be fixed by updating the display driver, if possible.
Status: As of January 2009, we believe the current Intel drivers may solve the problem. Intel recommends using the Intel® Driver Update Utility to help you find the proper updated driver for your system.
- Crash when opening Views in Windows XP
Description: This problem has been reported by users of NVidia GeForce-based cards. Apparently some capability WCS and VNS make use of encounters a bug in the OpenGL card driver when Windows XP's "Visual Themes" are enabled. WCS or VNS crashes immediately upon opening a View when running under Windows XP.
Affected cards:
- NVidia GeForce based, possibly others.
Workarounds: Turn off 'Visual Themes' when using WCS/VNS. Find the WCS.exe or VNS.exe file. Right-click on the file, and select the 'Properties' menu item. When the properties window opens, switch to the Compatibility tab, and check the "Disable Visual Themes" checkbox.
Status: We believe this is a driver bug, and cannot be fixed by 3D Nature.
Update: (October 2002) WCS 6.02 and VNS 1.20 are both now able to detect situations where this problem would manifest and disable the window style which causes the problem. This results in no visual distinction between Docked and Undocked windows, but under Windows XP's standard Theme, the difference is basically indistinguiashable anyway, so no (additional) functionality is lost. - Failure to Select (ALT-click or Command-click in Views)
Description: This problem is common among cards with poor ("game grade") OpenGL implementations that can draw graphics reasonably well, but lack the more sophisticated OpenGL glRenderMode(GL_SELECT) functionality. Users will find that displays (may) look fine, but will be unable to use the ALT-click (Command-click on Mac) capability to instantly select an object in a View with the mouse.
Affected cards: (If your card exhibits this problem and is not listed here, perform an OpenGL benchmark and send the results to us.
- Numerous.
Workarounds: Typically, unless there is a newer driver for your card that fixes the problem, there is no workaround.
Status: This is a driver bug, and cannot be fixed or worked around by 3D Nature.
- Corrupt Texture Overlays
Description: This problem indicates a problem with texture coordinates in the card driver's handling of texture coordinates. Often the gradient overlays in Views will exhibit strangely gradiated colors around the edges of the View, and no gradiation at all elsewhere.
Example:
Affected cards: (If your card exhibits this problem and is not listed here, perform an OpenGL benchmark and send the results to us at our GL Bugs address.
Workarounds: In the case of the Matrox cards, the symptom only appears when the card is running in 24-bit display depth. Switching the card to 32-bit or 16-bit depth produces acceptible results. Note, some Matrox cards have performance reduced or have problems running dual-headed when they are not in 24-bit mode, therefore this is not always an acceptible workaround.
Status: Recent user reports indicate that Matrox driver revision nt4_473 seems to fix this problem. Version numbers seem conflicting here, so even if you appear to already have this version of the driver, if you encounter the problem, try getting the latest driver from Matrox.
- Views go black after drawing
Description: Views open and draw ok, but immediately upon completion of drawing, they go black. This indicates a failure of the glReadPixels() call WCS uses to make a backup copy of the window contents for quick redrawing should another window or application obscure the View momentarily. A workaround is available to alleviate this, but it has some side-effects. See Workarounds below.
Affected cards: (If your card exhibits this problem and is not listed here, perform an OpenGL benchmark and send the results to us.
- Intergraph Wildcat Series cards
- SGI Cobalt Series (Visual Workstation 320 and 520)
- E&S Tornado 3000
- ELSA GLORIA II
Workarounds: A workaround for this problem is available to produce useable functionality on most systems. Enabling this workaround tells WCS to use it's older (V4) method of making a backup copy of the window contents. This older method may be a slight bit slower, and will cause 'window garbage' to occasionally be visible in Views after another obscuring window is moved out of the way. WCS V4 owners may already be familiar with this side-effect, as this is how WCS V4 always behaved. avoid_glreadpixels=yes
Status: This has been determined to be an 'undefined behaviour' of the OpenGL graphics system. Technically WCS should not rely on this working, though it does in the majority of graphics cards. We are looking into ways of making this work for all cards.
by Cards Exhibiting Problem:
- Intel GMA-based chipsets
Manufacturer's Website:http://www.intel.com/products/desktop/chipsets/ - Matrox G400 and G450
Manufacturer's Website:http://www.matrox.com - Intergraph Wildcat Series
Manufacturer's Website:http://www.3dlabs.com - SGI Cobalt Series (Visual Workstation 320 and 520)
Manufacturer's Website:http://www.sgi.com - E&S Tornado 3000
Manufacturer's Website:http://www.es.com/ - ELSA GLORIA II
Manufacturer's Website:http://www.elsa.com