Nathan Kopp <pov### [at] nkoppmailshellcom> wrote:
> I disagree.  I think mip-mapping would be quite useful in a ray tracer.
> Mip-mapping is a computationally cheap way to achieve great texture
> anti-aliasing results.  In many situations, you'd need to shoot tons of AA
> rays to achieve the same effect as mip-mapping.

  Another place where mipmapping is really useful is, of course, where
it's usually used, ie. in mapping an image onto a surface. Scanline
renderers invariably support this and it affects the quality of the
texture when the pixels of the image map (texels) are smaller than the
pixels of the rendered image.

  (Of course mipmapping has to be used in conjunction with trilinear
filtering, or else you'll get ugly and very visible transition lines
where the mipmap level changes, but this is a whole different story.
Another different story is that trilinear filtering is not perfect,
but to get a perfect result you need to use a more advanced algorithm
(I think it's called anisotropic filtering or something like that).)

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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