Back to the 13 june 2000, Peter J. Holzer draws my attention to
a strange behavior of the orthographic camera with the superellipsoid object.

In fact, this bug is not limited to the orthographic camera, it
just manifest itself more easily with it!

Images of the various aspect are going to be posted in p.b.i
(as png, not jpeg) (their scripts in p.t.s-f)


first image (super.png) illustrates the "missing" picture of one
superellipsoid, when looked under the correct angle
 (who need the no_image patch with such a bug ?)
There is really four superellipsoid on each row, and three by column!

Rending with or without AA does not change the problem.

second image (super2.png) illustrates the same aspect of the bug
with a default camera. please notice the single pixel at the
very center of the picture: it is the background !!!

Rending with AA does reduce the problem.

third and fourth images (super3.png and super4.png) illustrate another aspect of
the bug
when a rotation is added to a superellipsoid with small parameter values:
the camera sometimes see the inside, sometime the outside (well for the
illumination 
at least).

Rending with or without AA does not change the problem.


I have the solution:

in super.c, at the end of the intersect_box(...) function, 
before the last statement ( "return (TRUE);" ), there is
two lines outside any if block:

*dmin = tmin;
*dmax = tmax;

The correction is simple: remove these two lines.


Any volonteer to post a message to povray.bugreports ?

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