"SharkD" <nomail@nomail> wrote:
> Dan Connelly <djc### [at] yahoocom> wrote:
> > Trevor G Quayle wrote:
> >
> > > 1351 X 1170
> > > 1560 x 1351
> > > both have a difference of 0.000027%
> >
> > Here's a list of ratios which do the best, for sizes up to that ratio, or
reproducing the desired aspect ration:
> >
> > W    H    error
> > 1    1    0.154700538379252
> > 4    3    0.133974596215561
> > 5    4    0.0762395692965987
> > 6    5    0.0377495513506236
> > 7    6    0.010256681389213
> > 15   13   0.00074046659535143
> > 52   45   0.000739918710263021
> > 67   58   0.000408489164229975
> > 82   71   0.000198314330160265
> > 97   84   5.31420220913903e-05
> > 209  181  3.81553418438152e-06
> > 724  627  3.815519626027e-06
> > 933  808  2.10609814010887e-06
> > 1142 989  1.02236683030554e-06
> > 1351 1170 2.7394246893131e-07
> > 2911 2521 1.96681873010363e-08
>
> None of the values you've listed match the correct aspect ratio. For instance,
> 2521 * ~1.73 = ~4367, and 1170 * ~1.73 = ~2026. Also, precision is important
> because the pattern in the tiles needs to line up with an identical pattern in
> a larger image. Also, the tiles themselves must have a low resolution. None of
> the low-resolution options seem to have an acceptible margin of error.
>
> -Mike

Actually precision isn't that important as the camera aspect ratio and image
ratio do not need to be the same.  While the image aspect ratio is restricted
to integer combinations, the aspect ratio of the camera can be set to the exact
mathematical ratio.  For example try setting your image resolution as square
(say 400X400) and your camera as 2:1 and reder a sphere.  The 1x1 ratio render
will get stretched to the 2x1 ratio image and look distorted.
What happens is that the image gets distorted to fit the image size, but with a
low ratio error, it should be unnoticeable


For resolutions of width 1600 or less, these are the ones with less than 0.001%
error:

1351 x 1170 (0.000027%)
1560 x 1351 (0.000027%)
1142 x 989 (0.000102%)
933 x 808 (0.000211%)
724 x 627 (0.000382%)
1448 x 1254 (0.000382%)
627 x 543 (0.000382%)
1045 x 905 (0.000382%)
1254 x 1086 (0.000382%)
1463 x 1267 (0.000382%)
209 x 181 (0.000382%)
418 x 362 (0.000382%)
836 x 724 (0.000382%)
1239 x 1073 (0.000510%)
515 x 446 (0.000691%)
1030 x 892 (0.000691%)
1545 x 1338 (0.000691%)
1575 x 1364 (0.000732%)
1366 x 1183 (0.000786%)
1336 x 1157 (0.000859%)
1157 x 1002 (0.000859%)
821 x 711 (0.000964%)
948 x 821 (0.000964%)

-tgq

Post a reply to this message