Jim Holsenback <spa### [at] nothanksnet> wrote:
> On 9/25/2016 6:03 PM, clipka wrote:
> > Am 25.09.2016 um 22:37 schrieb Jim Holsenback:
> >> On 9/25/2016 4:23 PM, Jim Holsenback wrote:
> >>> attached is modified file ...
> >>
> >> that i'll teach me to do it from memory ... attached is corrected
> >> version .... #case (1) | #case (2) NOT #case (1|2)
> >
> > Actually it should be `#case (1) #case (2)`. Nothing in between. If you use
> >
> >     #case (1)
> >       ANYTHING
> >     #case (2)
> >       WHATEVER
> >     #break
> >
> > you'll effectively get `ANYTHING WHATEVER` for a value of 1, and
> > `WHATEVER` for a value of 2.
>
> doh ... tested with 2nd case and it passed. when i changed to 1st case
> it belched on |
>
> attached is repaired version

First of all, thanks for supplying this test of the tiling pattern. I wasn't
aware of it, or had long since forgotten.

Something I was looking at by using that scene file was to find out how those
patterns would repeat as, well, tiles. Noticing you were rotating the original
tile to make 4 instances I wanted to see them side by side without rotation.

I replaced the scaling of box texture with the following, commenting out the
rotated boxes to put in moved boxes. I used animation to create the series of
images, which is why frame_number is here. That was put into the TilingPattern
declare also. Here's the other change at end of the box object:

#if (frame_number=19|frame_number=20)
scale TileScale /* no differences of tiling pattern 19 and 20 at this scale */
#else // some other scales do not tile repeatedly
scale TileScale/2 /* other patterns tile repeatedly except Penrose 25, 26 and 27
*/
#end
  }
  scale <5,1,5>
} // box

object {TestCase} // about to move tiles around, not rotate
object {TestCase translate <-5,0,0>}
object {TestCase translate <-5,0,-5>}
object {TestCase translate <0,0,-5>}

/*
#local YDir = 0;
#while (YDir < 360)
  object {TestCase rotate y*YDir}
  #declare YDir = YDir + 90;
#end
*/

Now a quandary about those 19 and 20 patterns. Apparently they each track
somewhat opposite (not exact) directions but are seen as identical with this
particular scale of just TileScale, the original. However it can be seen if
scaled smaller, except not able to repeat from what I've seen. I already tried
mirroring, too, but maybe not enough things to discover the repeating pattern
for individual tiles.

Had me thinking it might be one of those Penrose patterns before I realized
those were said to be the last three. Of course I don't know what any of these
are really, besides interesting!

And this was a good opportunity to say thanks to everyone still working on the
POV-Ray stuff.

Bob

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