On 5/5/20 1:34 PM, Bald Eagle wrote:
> William F Pokorny <ano### [at] anonymous org> wrote:
>
>> I'm going make another attempt at an inbuilt function for this. If
>> you've tweaked something in the code from the previous few posts, please
>> let me know.
>
> Nope - Just been playing around with it a bit to make sure the outer and inner
> shapes are truly elliptical (they are).
>
...
>
A quick note and image.
I ran at an f_elliptical_torus() again today and again failed. Ended up
almost exactly where I did last time for result. :-(
My implementation of your recent code worked straight up with different
a=b sizes this time. When a=b we match Bruno's result - and that of
f_torus() for that matter. When A close to B results is pretty close as
in the top row, but if A and B much different it falls apart.
FYI. I'm comparing against Bruno's sphere_sweep version which looks good
to me for shape and OK for comparisons. However, the sphere_sweep itself
won't render at all cleanly in some orientations / sizes due bugs with
the sphere_sweep if using v37 / v38. My povr updates mostly work with
the orthographic camera - except for some speckles you can see in the
comparisons.
Aside: The orthographic rays to a flat sphere_sweep the worst case
solver wise because the two roots collapse to a multiple with which
solvers struggle. I have a patch in TCL for some of these (missed roots
after polynomial deflation), but not yet found myself putting it in.
If the mood hits me, I'll spend some time trying to digest what Bruno
really did. Review too my version of your code, but this time not too
different from yours. Might try your SDL straight up - I didn't do that
this time... Work for another day.
Bill P.
Post a reply to this message
Attachments:
Download 'eltorusfail.jpg' (91 KB)
Preview of image 'eltorusfail.jpg'
|
