Tom Melly <tom### [at] tomandlucouk> wrote:
> From what I understand of this debate, does this resize-for-better-aa really
> break the rules, either in spirit or fact?

  If we read the rules literally, resizing is allowed. There isn't anything
saying which resizing methods are allowed and which aren't; resizing is just
allowed, period. So resizing is not technically against the rules.
  However, IMHO using resizing as a method for improved post-process
antialiasing breaks the spirit of the IRTC rules. It's effectively a
post-process filter applied to the rendered image with a paint program.

  I am pretty sure that the people who allowed resizing when writing the
IRTC rules didn't think about this possibility and if they had known about
it, they would have thought more carefully.

> I take your point that to resize to get rid of artifacts is a definate no-no,
> but the aa issue seems linked to the size of the image-output, rather than an
> inherant problem with the scene.

> In other words if the defect corrected by resizing is present in the high
> resolution image, then you are breaking the rules. However, if the defect is not
> present at high res., and you are merely trying to duplicate the "clean" image
> at a lower-res. then I don't think any rules, spirit or fact, have been broken.

  If you make, for example, the typical checkered-floor image (where you can
see the horizon), you will get aliasing artifacts no matter how big you render
the image. However, rendering at for example 8000x6000 and then resizing
it to 800x600 (by using some averaging algorithm) will get rid of most of
the artifacts (if not all of them). This is because most of the artifacts
are pixel-sized and what the resizing does is to calculate the average of
10x10 pixel squares, and these artifact pixels contribute little to the
average, thus practically disappearing. Thus resizing removes the artifacts
produced by the renderer.

-- 
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}//  - Warp -

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