Re: Calculating normalized patch coords from pixel coords?

[Christian W. <cwa...@gm...>]

> In order to have a patch work across 3d space, and not be hindered  
> by the seperate cube faces, I wondered if there was a way to  
> calculate, with the 2D coords(e.g. face 1, 342, 567) the equivilent  
> in 3D coords?

Sure, you have everything you need. You can get the pixel dimensions  
of the background face from 'w, h =  
pipmak.getimage("myface.jpeg"):size()', and the geometrical  
arrangement of the face images in 3D space is shown in figures 2 and 3  
in the manual. An edge of the cube is two units in normalized units  
and (w-1) or (h-1) in pixels, which gets you the scale factor, and as  
a fixed point you know that (w/2, h/2) in pixels is (0, 0, -1) in  
normalized coordinates (the center of the face), for face 1, and so on  
for the other faces as shown in figure 2.

  -Christian