POV-Ray : Newsgroups : povray.newusers : How to use self defined functions as patterns? : Re: How to use self defined functions as patterns? Server Time 1 Mar 2024 16:36:35 EST (-0500)
 Re: How to use self defined functions as patterns?
 From: Kenneth Date: 5 Apr 2018 00:10:01 Message:
```
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"headline": "Re: How to use self defined functions as patterns?",
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"Thorsten Froehlich" <nomail@nomail> wrote:
> "Kenneth" <kdw### [at] gmailcom> wrote:

> > BTW, somewhere in the POV-Ray documentation, it states that when using a
> > function as a pigment or pigment pattern, the 'image' of the function is
> > actually just an infinitely thin slice, taken in the x/y plane (x from 0.0 to
> > 1.0, y from 0.0 to 1.0). You can change the location of that slice, though:
> >                  #declare Foo = function(x,y){2*(x + 1.7) + 2*y}
>
> It does not say that, the pattern function is three dimensional, not two
> dimensional. You are free to not use all three dimensions though.

Hmm. I was probably thinking of a 'function image' instead--
3.6.2.1.12.2 Function Image
"Note: Functions are evaluated on the x-y plane. This is different from the
pattern image type for the reason that it makes using uv functions easier"

"Width and Height specify the resolution of the resulting 'internal' bitmap
image. The image is taken from the square region <0,0,0>, <1,1,0>"

Sorry for the confusion. Yes, POV-ray's patterns are 3-dimensional. But the
example images in the docs (at  3.6.2.1.12 Function Pattern)  *appear* to be
only 2-dimensional there as well-- or rather, taken from what looks like a 2-D
'slice' ;-)
```