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Re: Slow polygon anti-aliasing

> well, i would imagine it wouldn't be very easy (if possible at all) to do
> fast anti-aliasing in hardware

edge anti-aliasing is an available hardware feature of newer ATi cards.

http://www.ati.com/na/pages/products/pc/rage_magnum/index.html

full scene anti-aliasing solutions require cleverness (eg 3Dfx's T-Buffer)
to avoid serious framerate hits taken with a brute-force downsampling
or multisample approach.

> anti-aliasing in opengl - why couldn't you render a frame buffer twice the
> size as your window, then call that portion of memory a texture, and then
> draw it into your window as a big mipmapped texture, which would (i would
> imagine) acheive the same effect?

1) the actual source image would likely be 4x, not twice the size of your
target window.

2) GL_LINEAR blending mode gives you bilinear filtering, which is good
enough in this case. mipmaps are used for 'trilinear' filtering, where the
rendered image size is interpolated between two mipmap levels.

> i've noticed the dreamcast has some kind of anti-aliasing effect
> (although it seems to partially from interlacing), and it doesn't seem to
> have hardware that's that far beyond consumer 3d cards, plus it also has
> (some kind of bizarre) motion blur. so why can't we do these things?? i'm
> sure i'm just missing something obvious

OpenGL's buffer -> texture copying capability is accessed with
the glCopyTexImage2D() and/or the glCopyTexSubImage2D() calls.

=td=

--
3D API Engineer, Apple OpenGL Group



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