I've been having no luck getting orthographic cameras to work with the new
syntax introduced a few versions ago, so while waiting for the documentation
to catch up on this feature I've been trying to simulate orthographic views
by placing the camera very far away and using a very small angle to zoom in.
That's how I stumbled on this bug:

/***** START *****/
torus {10,5 texture {pigment {color rgb 0.8}}}


//camera {location <0,100,0> look_at <0,0,0> angle 75}
camera {location <0,5000,0> look_at <0,0,0> angle 1.5}

light_source {<0,10000,0> color <1,1,1>}
/****** END ******/

If you use the first camera, the scene renders correctly. If you use the
second far-away camera, all kinds of surface artifacts appear on the torus.
None of the other primitives that I use in my scenes (box, sphere, cylinder,
plane, cone, prism, text) show these artifacts, but there are several that I
don't use so I haven't checked them all.

This looks exactly like what happens with a sphere_sweep object if the
tolerance value isn't set correctly. Is POV-Ray using sphere_sweep under the
covers to implement torus? Or is this bug part of the ongoing changes in the
camera object?

Thanks,
Scott Gammans

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