"Slime" <fak### [at] emailaddress> wrote:

> Because your mesh has relatively few polygons, it is suffering pretty badly
> from a known POV-Ray bug which is causing those black spots around the
> edges. If you don't have any shadowless lights in your scene, you can work
> around this bug by adding "double_illuminate" to the end of the mesh object.
>
> You may also want to increase the polygon count in order to smooth out the
> edges and the shadow transitions along the surface.
>
Thanks for the tips. When I generated the geometry I didn't have much ram to
work with, and so I was forced to go with a low poly count (150,000
rectangles before exporting). I have access to some much beefier hardware
though, and next time I render it I'll have five times as many polygons up
my sleeve. That, with your suggestion to turn on double_illuminate, should
alleviate the first two problems.

>
> > As said in the title, it is an inversion of a 3d truchet tiling.
>
> Oh, of course! A truchet tiling! What's that? ;)
>
Sorry about that, didn't want to bore everyone with the details. Since you
asked though... a truchet tiling is formed from a single special tile which
is laid down side by side without regard to orientation. The tile is chosen
so that its pattern at any side joins smoothly with any other side. Its a
bit hard to explain, so check out
http://mathworld.wolfram.com/TruchetTiling.html for an example. Anyway you
can do the same thing in 3d with a cube containing, say, three one quater
segments of a torus. Once you have your 3d 'tile', you can stick a bunch of
them together, and then use the operation r -> r/(r.r), where r is a vector
representing any point, to get the effect in the image posted.

Thanks again for the tips, version 2 should be miles ahead of my first
attempt.

Post a reply to this message