Page 1 of 2 12 LastLast
Results 1 to 10 of 20

Thread: Multitexturing with GL_ARB_multitexture

  1. #1
    Junior Member Newbie
    Join Date
    Feb 2000
    Posts
    14

    Multitexturing with GL_ARB_multitexture

    I am getting an "invalid operation" message error from my OGL error checking code whenever I use more than 2 textures--specifically when I use the glActiveTextureARB(GL_TEXTURE2_ARB) command. All three texture are there and seem to be working fine--why am I still getting these error messages?
    Nathan E Brown

  2. #2
    Junior Member Newbie
    Join Date
    Feb 2000
    Posts
    26

    Re: Multitexturing with GL_ARB_multitexture

    Originally posted by nebrown1:
    I am getting an "invalid operation" message error from my OGL error checking code whenever I use more than 2 textures--specifically when I use the glActiveTextureARB(GL_TEXTURE2_ARB) command. All three texture are there and seem to be working fine--why am I still getting these error messages?
    You have to check how much texture units you can use:
    GLint maxUnits = 0;
    glGetIntegerv(GL_MAX_TEXTURE_UNITS_ARB, &maxUnits);

    You can use at most "maxUnits" texture Units!

    Kosta

  3. #3
    Junior Member Newbie
    Join Date
    Feb 2000
    Posts
    14

    Re: Multitexturing with GL_ARB_multitexture

    Thanks for the help. Sure enough, I only have 2 textures available. Why is that? Is it because of my video card, OpenGL version, or what?
    Nathan E Brown

  4. #4
    Senior Member Regular Contributor
    Join Date
    Feb 2000
    Location
    milano, italy
    Posts
    282

    Re: Multitexturing with GL_ARB_multitexture

    mainly it depends on the card.
    multitexturing, to be fast and efficent, has to be performed in hardware.
    the tnt/tnt2 has a 2-stage texture pipeline, so it can at most perform a blend between two textures in a single pass.
    if i'm not wrong, the nv10 (geforce) has a 4-stage pipeline.

    however, opengl supports at most 32 textures, ranging from unit 0 to unit 31.

    Dolo/\/\ightY
    Dolo/\/\ightY

  5. #5
    Senior Member Frequent Contributor imported_cass's Avatar
    Join Date
    Feb 2000
    Location
    Austin, TX, USA
    Posts
    913

    Re: Multitexturing with GL_ARB_multitexture

    GeForce only has 2 texture units as well. I don't know of any hardware that supports more than 2 units right now. Interesting question, though.
    Cass Everitt -- cass@xyzw.us

  6. #6
    Senior Member Regular Contributor
    Join Date
    Feb 2000
    Location
    milano, italy
    Posts
    282

    Re: Multitexturing with GL_ARB_multitexture

    good to know!
    creative said something like "4-pixel pipeline..." and i thought it meant a 4-unit multitexturing capability, but i didn't took the time to test...

    Dolo/\/\ightY

    [This message has been edited by dmy (edited 03-16-2000).]
    Dolo/\/\ightY

  7. #7
    Senior Member Regular Contributor
    Join Date
    Mar 2001
    Posts
    319

    Re: Multitexturing with GL_ARB_multitexture

    The Radeon has 3 texture units. The Kryo and Kryo 2 can multitexture with as many as 8 textures (although they only have 2 units) - don't know how many they allow in OpenGL, though. I think that the pixel shaders on the GeForce3 can allow for quite a few texture stages, but again, I don't know if this is implemented directly (or only through NV extensions).

  8. #8
    Senior Member Regular Contributor
    Join Date
    Aug 2000
    Location
    Ocoee, Florida, USA
    Posts
    150

    Re: Multitexturing with GL_ARB_multitexture

    This is REALLY off topic but the Flipper supports 8 texture units at once in hardware AND its rumored to support OpenGL (thats a very loose rumor at this point though). For those that are unaware, the Flipper is the GameCube's GPU....



    [This message has been edited by BwB (edited 03-19-2001).]

  9. #9
    Senior Member Frequent Contributor
    Join Date
    Aug 2000
    Location
    Portsmouth, Hampshire, England
    Posts
    926

    Re: Multitexturing with GL_ARB_multitexture

    Cass, Have you ever seen an mpeg of Nvidia Geforce II GTS promo featuring Bungie's Halo?

    In it it states, the geforce 2 can use 8 textures at once??

    thought this was a bit mad, as doesn't Geforce 3 only have 4 texture units?

    bizarre...

    Nutty.

  10. #10
    Senior Member OpenGL Pro
    Join Date
    Feb 2001
    Location
    Switzerland
    Posts
    1,594

    Re: Multitexturing with GL_ARB_multitexture

    all have 2 textures in one pas, radeon has 3, gf3 has 4

    this is what i know, perhaps there is an other board wich has more.. or less ( voodoo1 didnt had multitexturing, had it? )
    http://davepermen.net - if i could stay true to my heart, i would feel totally free

Page 1 of 2 12 LastLast

Similar Threads

  1. GL_ARB_multitexture with cygwin
    By Alcionei Estevam Jr in forum OpenGL: Advanced Coding
    Replies: 1
    Last Post: 01-20-2003, 11:21 AM
  2. GL_ARB_MULTITEXTURE + GL_SPHERE_MAP
    By Andrea Rossini in forum OpenGL: Advanced Coding
    Replies: 1
    Last Post: 07-23-2002, 03:54 PM
  3. GL_ARB_multitexture && GL_TEXTURE_ENV_COLOR
    By ScottManDeath in forum OpenGL: Advanced Coding
    Replies: 2
    Last Post: 05-15-2002, 12:31 PM
  4. GL_ARB_multitexture decaling
    By Crunch in forum OpenGL: Advanced Coding
    Replies: 0
    Last Post: 03-30-2001, 08:39 AM
  5. GL_ARB_multitexture
    By Mad Max in forum OpenGL: Advanced Coding
    Replies: 2
    Last Post: 02-23-2000, 08:12 AM

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