POV-Ray : Newsgroups : povray.newusers : image_map to tilted and rotated triangle centered and scaled : Re: image_map to tilted and rotated triangle centered and scaled Server Time
6 Jul 2022 18:22:52 EDT (-0400)
  Re: image_map to tilted and rotated triangle centered and scaled  
From: jr
Date: 28 Mar 2022 08:45:00
Message: <web.6241acc4ccfe2900fc0c8de6cde94f1@news.povray.org>
hi,

"Molly-J" <nomail@nomail> wrote:
> I am going mad trying to project image maps onto polygons that are not in the
> x-y plane or plumb to the y axis. I have 20 equilateral triangles forming a
> typical D20 shape (regular icosahedron). I have the XYZ coordinates for the
> points so all I have to do is create each triangle using sets of the 32
> vertices. BUT . . . .
>
> I cannot work out how to project the 20 image_map pigments properly. Image_map
> pigments only seem to work on polygons normal to the Z axis and left corner at
> 0,0 XY

<https://wiki.povray.org/content/Reference:Image_Map>

once you've created the image_map, you'll want to scale it to correct
proportions, eg if the source is 1920x1080, the scale ought to read
'<1.92,1.08,1>'.


> The suggestion that I create each triangle at 0,0 and then translate/rotate them
> to the icosahedron would be just fine if i had those numbers. (I do not)

ok, I'll stop here 'coz confused, above you wrote "I have the XYZ coordinates
for the points".

if you do have those coords, create yr object in position (near origin, "image
is projected onto the object as though there were a slide projector somewhere in
the -z-direction"), then translate.  hth.


regards, jr.


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