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View Full Version : Beginner about multipass shaders



dorinm
10-31-2004, 12:41 PM
Hi ppl, bare with me as I am just a beginner in shaders&stuff ...whatever, here's may question(s):

-can I achieve multipass-shader effects using dependent texture reads? I mean , are these dep.text.reads used to achieve multipass shader effects?
-and if yes, how does the result of a pass can be used on next pass? yes, doind dep.t.reads, but what I ask are there any limitation on this ?(talking about NV35 and NV40).

thank you and excuse me if my questions weren't cler enough formulated.

plasmonster
11-01-2004, 04:36 AM
-can I achieve multipass-shader effects using dependent texture reads? I mean , are these dep.text.reads used to achieve multipass shader effects?Sure, you could say that. That's the beauty of shaders, they give you the freedom to do what you want, to a point. You're only limited by your imagination and your graphics card.


-and if yes, how does the result of a pass can be used on next pass? yes, doind dep.t.reads, but what I ask are there any limitation on this ?(talking about NV35 and NV40).P-buffers and CopyTexImage provide a means to capture rendered data for anything you desire. You can grab rendered data, bind it to a texture, then use it as input in a shader, for example. As for limitations, yes, there are always limitations (glGet*() is your friend here).

dorinm
11-01-2004, 06:12 AM
thank you, that P-buffer thing gave me an ideea ;) ...about CopyTexImage I'm not so sure, i heard it is really slow, and if I use 1024x1024 textures then it would be just overkill :D .