On Wed, 13 Feb 2002 12:01:20 -0800, Ben Chambers wrote:
> Simplified version (for the final viewing plane):
> Check the object's bounding hierarchy for the maximum and minimum elevations
> above the horizon, as well as the rotations from center.  Plot as a box.
> AFAIK, this is the method used for visa buffer.

Actually, the vista buffer is somewhat more complex, in that it actually
projects the bounding box onto the camera plane as a generalized hexagon.

> The current sampling method is color based, and works to ensure all portions
> of the screen look nice.  This method, being intersection based, deals with
> edges / small objects very nicely, but will not address aliased textures.

Correction: it deals with edges that are within a pixel of the edge of the
bounding box.  This is a far cry from all edges, even for simple boxes and 
cylinders (consider rotation.)

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbf 1}hollow interior{media{emission 3-T}}}#end 
Z(-x-x.2x)camera{location z*-10rotate x*90normal{bumps.02scale.05}}

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