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Thread: Normalization in Reg. Combiners vs. Cubemaps

  1. #1
    Senior Member OpenGL Guru
    Join Date
    Dec 2000
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    Reutlingen, Germany
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    Normalization in Reg. Combiners vs. Cubemaps

    Hi

    I just got normalizing in register combiners working. The paper i got the formula from, said that one condition is: "The angle between all pairs of the original per-vertex vectors is
    no more than 40š (or so)." And further on it says: "For models of reasonable tesselation (and/or reasonable distance to the light and viewer) #2 holds"

    I think this is quite strange. If i have a good tesselation, i donīt need to normalize the vector, at all, because the difference is really only minor. However if i DONīT have my data tesselated, i need normalization. But in this case it doesnīt work properly. I tested it, and i was extremly disappointed with the normalization. On one big poly it was only slightly better than without normalization.

    In my test-app cubemaps and register combiners were both equally fast. Therefore i would like to know, if it is worth tesselating my data a bit and using register-combiners? Or should i stick to my cubemap?

    Jan.
    GLIM - Immediate Mode Emulation for GL3

  2. #2
    Senior Member OpenGL Pro
    Join Date
    Aug 2000
    Location
    Portsmouth, Hampshire, England
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    1,063

    Re: Normalization in Reg. Combiners vs. Cubemaps

    I'd go for cubemaps, and avoid the extra work in the combiners.

  3. #3
    Senior Member OpenGL Guru
    Join Date
    Mar 2001
    Posts
    3,768

    Re: Normalization in Reg. Combiners vs. Cubemaps

    The question comes down to this: can you afford a second texture access? If so, use a cubemap. If not, use the RC normalization.

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