DP3 bump mapping with alpha

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2 comments, last by Moe 18 years, 2 months ago
Hi, Just for fun I was delving back into Fixed Function Pipeline and taking a look at DP3 bump mapping (never tried it before). I was wondering if it were possible to include alpha into the equation so that you get a partially transparent texture lit using DP3 bump mapping? My first attempts ended up with the light vector turning the texture black and therefore transparent. Any ideas of the renderstates I need to set up to simply light a texture using DP3 AND retain transparency without the transparency being affected by the DP3 operation? Does that make sense?
Byron Atkinson-JonesXiotex Studioswww.xiotex.com
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Since the fixed pipe DOT3 writes to all channels RGBA (your alphaop is ignored when colorop is DOT3), you just need to set up your alpha in any stage after the DOT3 is performed.
feel like an idiot now... missed that one completely!

Should have read the manual a bit more closely!


Works a treat - cheers.
Byron Atkinson-JonesXiotex Studioswww.xiotex.com
You have me interested now - I wouldn't mind seeing a screenshot if you could take one (yes, I know the DP3 won't be as cool looking in a screenshot, but I am interested in seeing what it does look like).

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