I already reported the problem in .bugreports, along with a few observations.
The problem persisted under DOS, so unless DOS also has a high epsilon value,
this is not the answer.

Margus

Dan Connelly wrote:
> 
> Chris Colefax wrote:
> 
> > cone {<-0.020957, 0, 0>, 0.299520, <-0.021942, 0, 1>, 0.298920}
> >
> > which can be reduced to:
> >
> >    cone {<0, 0, 0>, 100, <4, 0, 1000>, 99}
> 
> I wonder if this is a problem related to the W95 code's high value
> of epsilon, similar to the sphere problem.  If so it should not show
> up in the UNIX and Mac versions, bothe of which have lower values.
> 
> The W95 version has EPSILON of 1e-5, quite a high value.  Then
> the code has a line of the form, in cones.c :
> 
>   {
>     /* Solve intersections with a cone */
> 
>     a = D[X] * D[X] + D[Y] * D[Y] - D[Z] * D[Z];
> 
>     b = D[X] * P[X] + D[Y] * P[Y] - D[Z] * P[Z];
> 
>     c = P[X] * P[X] + P[Y] * P[Y] - P[Z] * P[Z];
> 
>     if (fabs(a) < EPSILON)
>     {
>       if (fabs(b) > EPSILON)
>       {
>         /* One intersection */
> 
> It isn't hard to see how this coule encounter problems with
> differences in radius of 10^-3.
> 
> I strongly suspect this is another problem with the large epsilon value,
> similar to the ellipsoid route problem already reported in
> news://news.povray.org/povray.bugreports .
> 
> Dan
> --
> http://www.flash.net/~djconnel/

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