POV-Ray : Newsgroups : povray.bugreports : Bad cylinder warp causes crash : Re: Bad cylinder warp causes crash Server Time
15 Jun 2021 09:33:26 EDT (-0400)
  Re: Bad cylinder warp causes crash  
From: Bald Eagle
Date: 1 Dec 2018 16:35:01
Message: <web.5c02fdf77cc2800765e06870@news.povray.org>
"jr" <cre### [at] gmailcom> wrote:


> like green, I know nothing about warp.  but wrt termination, would loading the
> image "once" not automatically provide a/the limit(s)?

A warp is just a modification of a pattern.  Rather than just straight mapping
it to Cartesian 3D space, it bends, wraps, folds, repeats, or otherwise changes
how the pattern is evaluated based on the <x, y, z> you're at.

If you look at the wiki entry (about 3/4 down the page),

http://wiki.povray.org/content/Reference:Warp

you'll see

Although these warps do 3D mapping, some concession had to be made on depth.

The distance exponent is controlled by using the dist_exp keyword. When using
the default value of 0, imagine a box from <0,0> to <1,1> stretching to infinity
along the orientation vector.

The distance keyword is evaluated as follows:

sphere: distance from origin
cylinder: distance from y-axis
torus: distance from major radius
The planar warp was made to make a pattern act like an image_map, of infinite
size and can be useful in combination with other mapping-warps. By default the
pigment in the XY-plane is extruded along the Z-axis. The pigment can be taken
from an other plane, by specifying the optional vector (normal of the plane) and
float (distance along the normal). The result, again, is extruded along the
Z-axis.

The cubic warp requires no parameters, and maps an area in the x-y plane between
<0,0> and <1,1> around the origin in the same way as uv-mapping an
origin-centered cube-shaped box would. The cubic warp works with any object
whereas the uv-mapping only works for the box object. See the section on box
uv-mapping for details.

----------------------------------------------------------------------

So I can only imagine that the problem lies in exceeding / overflowing the
memory used in extending the pattern out along a radial path.


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