Results 1 to 8 of 8

Thread: OpenGL and the Detonator drivers of Nvidia

  1. #1
    Member Newbie
    Join Date
    Aug 2002
    Location
    Germany
    Posts
    35

    OpenGL and the Detonator drivers of Nvidia

    Hi,
    maybe some of you have already bad experience with the drivers of Nvidia.
    Do you know that they don`t support blending using glBlendFunc(GL_ONE_MINUS_DST_ALPHA,GL_DST_ALPHA) ?
    I tried as hard as i could, but this is the only way to achieve my objective: that a background picture shines nicely through the rendered objects.
    Do you know some other solution/trick...?

    Thanks,
    Tresher.

  2. #2
    Senior Member Regular Contributor
    Join Date
    Jun 2003
    Posts
    177

    Re: OpenGL and the Detonator drivers of Nvidia

    This is probably a stupid question, but do you have an alpha channel in your draw buffer? Do you render anything with alpha != 1.0?

  3. #3
    Member Newbie
    Join Date
    Aug 2002
    Location
    Germany
    Posts
    35

    Re: OpenGL and the Detonator drivers of Nvidia

    Well, yes i have
    I know that my blending method works, since i have no problems while i use other drivers (those from Asus for instance). But i am sure that many people are using the Nvidia drivers...

  4. #4
    Senior Member OpenGL Pro
    Join Date
    Oct 2000
    Location
    Fargo, ND
    Posts
    1,753

    Re: OpenGL and the Detonator drivers of Nvidia

    And you make sure you have a destination alpha when you create your window? (e.g. By using GLUT_ALPHA in glutInit if using glut, or getting a PIXELFORMATDESCRIPTOR that has cAlphaBits > 0 if using the Win32 API.)
    Deiussum
    Software Engineer and OpenGL enthusiast

  5. #5
    Member Newbie
    Join Date
    Aug 2002
    Location
    Germany
    Posts
    35

    Re: OpenGL and the Detonator drivers of Nvidia

    Thank you very much. It works now using GLUT_ALPHA. I thought i had an alpha channel in my DrawBuffer, because the RedBook doesn`t mention this option at all.
    Of course one question arises now:
    1. Why did it work with some drivers and with others not ?

    Though, for me this is unimportant... )) IT WORKS !

  6. #6
    Senior Member OpenGL Pro
    Join Date
    Oct 2000
    Location
    Fargo, ND
    Posts
    1,753

    Re: OpenGL and the Detonator drivers of Nvidia

    It's possible that the other drivers were giving you a "best fit" pixel format that just happened to include an Alpha buffer. I think glut simply uses ChoosePixelFormat to find a PIXELFORMATDESCRIPTOR with the stuff you requeset. ChoosePixelFormat will return something that has at least what you request, and potentially other stuff.

    I ran into a similar problem with porting a glut app to Linux once. I hadn't explicitly requested a depth buffer using GLUT_DEPTH because with Windows and glut, I always got a depth buffer anyway. With Linux, I didn't get a depth buffer unless I explicitly requested one.
    Deiussum
    Software Engineer and OpenGL enthusiast

  7. #7
    Member Contributor
    Join Date
    Jul 2003
    Location
    va beach
    Posts
    63

    Re: OpenGL and the Detonator drivers of Nvidia

    Odd since I use the latest Detonator from nVidia and experience no problems with the glBlendFunc().

  8. #8
    Senior Member Regular Contributor
    Join Date
    Jun 2003
    Posts
    177

    Re: OpenGL and the Detonator drivers of Nvidia

    Odd since I use the latest Detonator from nVidia and experience no problems with the glBlendFunc().
    If you read the rest of the thread, you'd realize that it wasn't a driver bug, but an app bug: If you don't ask for a frame buffer with an alpha channel, you may not get an alpha channel, so destination-alpha blending will not give you the behavior you expect.

Similar Threads

  1. OpenGL Vsync with latest nVidia Detonator
    By breakdown in forum OpenGL: Windows
    Replies: 2
    Last Post: 08-29-2004, 02:55 PM
  2. OpenGL + W2K + Detonator Drivers
    By in forum OpenGL: User Software
    Replies: 1
    Last Post: 10-11-2002, 09:38 AM
  3. Replies: 2
    Last Post: 07-15-2002, 11:47 PM
  4. NVidia Detonator 23.11 Drivers on XP
    By dslater in forum OpenGL: User Software
    Replies: 3
    Last Post: 12-19-2001, 09:37 PM
  5. Detonator Drivers and 3D-Glasses
    By in forum OpenGL: Basic Coding
    Replies: 3
    Last Post: 11-18-2000, 02:08 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Proudly hosted by Digital Ocean