TonyB wrote:
> 
> Did you check out the link? It's pretty cool. Gamasutra is a great site,

> they manage to reduce the computations from 3978 adds and 8586 multiplies to
> 1506 adds and 1488 multiplies. I have no idea how useful this would be to
> POV-Ray, however. I also found out where the Nintendo developers go to. =)

I discovered it several months ago.  It truly is a valuable resource on
several topics in graphics programming.

-Mark Gordon

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Thorsten Froehlich <tho### [at] trfde> wrote:
: Hmm, for now a workaround migth be to use an external program to scale down
: the image and use that as image map. Not a great workaround I have to admit,
: but it will work (if Nieminen needs a workaround right now).

  But then the image map will not be detailed near the camera.
  And no, it's not a problem I'm currently having. It's just an idea.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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On 9 Nov 1999 07:43:37 -0500, Nieminen Juha
<war### [at] punarastascstutfi> wrote:

>  Now, povray only supports bilinear filtering. How about adding automatic
>mipmapping and trilinear filtering to it?

What about implementing bicubic interpolation, similiar to Photoshop?
That program seems to resize images very well.

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On Tue, 23 Nov 1999 10:20:59 -0500, Glen Berry <7no### [at] ezwvcom>
wrote:

>What about implementing bicubic interpolation, similiar to Photoshop?
>That program seems to resize images very well.

Bicubic interpolation is supported by POV. Check out "bitmap
modifiers" in the docs.


Peter Popov
ICQ: 15002700

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[On 9 Nov 1999 07:43:37 -0500, Nieminen Juha <war### [at] punarastascstutfi>]
|   However, when the texels are smaller than the screen pixels, the bilinear
| interpolation doesn't help much. 

True, that's why we have antialiasing.

| like broken lines, moire patterns, etc (even when antialiasing in on)

Not if used correctly. You should try the adaptive supersampling.

|   In most 3D engines (renderers, 3D games, 3D video cards...) this problem
| is corrected by calculating mipmapping and trilinear filtering.

True. But the reason they do this is because it's more convenient than
proper antialiasing like the one we have in POV-Ray, and it's easy to
implement in hardware. Also, trilinear filtering bring on other visual
artifacts. For instance, resolution drops in both directions when a
texture is viewed at an angle. Hardware tries to cope with this by
introducing so called anisotropic filtering, but that also has it's
limits.

In POV-Ray, supersampling can be used to correct any aliasingproblems
you may have, and it will work on any texture, not just image maps.

| The result is very good.

It pales in comparison with proper supersampling.

-- 
A penny for your thoughts.
Mine are more expensive.

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>In POV-Ray, supersampling can be used to correct any aliasingproblems
>you may have, and it will work on any texture, not just image maps.

Not really.  Textures should antialias themselves based on the "size" of
the ray hitting them, as well, if you want to avoid certain kinds of aliasing.

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

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