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earth_walker
07-29-2003, 09:09 AM
I know what "r" "g" "b" means, and guessed "a" is the priority of displaying, such as (1,0,0,1) should be infront of (0,0,1,0.5), but according to the test, this is not true.

Can you tell me what does it mean?

Thank you!

starman
07-29-2003, 09:15 AM
'a' is for "alpha" and is used for transparency and blending. Read the Red Book section on Blending for a full description:
http://tassadar.physics.auth.gr/~chameleon/OpenGL/The%20Red%20Book/chapter06.htm#1

earth_walker
07-29-2003, 10:38 AM
Thank you!