Andrea Ryan <ary### [at] global2000net> wrote:
: POV-Ray makes pictures by shooting rays from the camera into the scene
: but how do scanline renderers create images?

  Put in a very simple way:

  Scanline renderers project the polygons on screen, ie. they take all the
3D vertices of the polygon, project them on screen, thus converting them to
regular 2D polygons and then they draw that polygon as if it was just a
2D one.
  Of course if the polygon has texturing, it has to be done with perspective
correction for it to be right.

  There are several methods for hidden surface removal. The best one of them
is using a Z-buffer which makes a perfect removal and allows things like
space cutting (ie. two polygons intersecting).

  You can easily imagine how fast this is.
  This is the technique used by 3D accelerator cards.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):_;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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