Geforce GTX 275 and OPENGL C3D 2010

[ActiveEarth]

We have two machines with Geforce 275 Cards that support opengl. We are running C3D2010. What can we do do enable to opengl here. We are running windows 7, 4 gig ram, quad core 6600. All the driver and other updates have been done. I have high and low over the net with no luck. I cant find the ini or cfg file that determines the option of opengl or d3d. Any help with this would be much appreciated.

[dperde]

Did you type 3dconfig and manual tuned the hardware settings?

[andrewpuller3811]

on the command line try "3dconfig"

Then select manual tune button. At the top, the pull down which you can use direct 3d or Autodesk(which from memory is OpenGL).

[ActiveEarth]

Thanks. I wasn't aware that the "Autodesk" setting was in fact Opengl. Can anyone confirm this? I would have expected the performance to much better 

[Sinc]

To the best of my knowledge, the "Autodesk" driver is also DirectX.  I'm not too up on the graphics, but to my understanding, the difference is that the "Direct3D" driver uses fixed-function piplines, while the "Autodesk" driver uses the newer shader pipelines.  The fixed-function pipelines had all shading effects hard-coded, while the newer shader pipeline allows for custom shading effects, yielding greater possibilities for graphics effects.

I do not know how to use OpenGL with C3D/Win7.  If it's possible, I'm not sure how you do it.  As you might expect, Microsoft has really be trying to minimize OpenGL in favor of their own DirectX.

Autodesk claims that, the first time you launch Autocad after installation, it will analyze your hardware, and automatically choose the driver that works best on your hardware.  I haven't done any testing myself to see if this feature works as-advertised or not, though.

[Sinc]

...and now I notice that in C3D 2011, it looks like the "Direct3D" mode is no longer available, and the only choice is "Autodesk" (unless you have a Quadro FX and the performance drivers installed).

So it looks like, if you have an older graphics card that doesn't support the shader pipeline very well and runs better with the "Direct3D" driver in C3D 2010, you may want to look at replacing that card for C3D 2011.

[ActiveEarth]

Does anyone know where the xml file that contains the approved hardware list exists? This is the same file that updates under the config window. The name of the file comes up when you update but I forgot what it is. My bet is if you edit that file the add your particular video card you'll get the functionality back.