Alpha channel and performance

New Message Reply Date view Thread view Subject view Author view

Mason D. Menninger (mason++at++praxis.jsc.nasa.gov)
Tue, 26 Oct 1999 17:09:50 -0500 (CDT)

I have a question regarding rgba vs rgb textures. I was
hoping someone could give me an idea of what kind of
performance hit I should expect if I use four channel
instead of three channel textures. I know it involves
more than just disk space and memory usage. Alpha makes
the scene more complicated to sort. But how much more
work do these factors add to rendering the world when
using Performer?

The answer is probably scene specific, so here's a little
info about what I'm dealing with. I typically have a few
very large textures (1024x1024 to 256x256) that include
alpha. There are usually three or four of these textures
placed on the same number of tiles that are essentially
co-planer. There are a few bits of geometry here and
there but the tiles compose the bulk of the scene.

So what kind of damage am I doing if I choose to use
the alpha channel in this manner?

                -Mason
                mason++at++praxis.jsc.nasa.gov

New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Tue Oct 26 1999 - 15:10:09 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.