William F Pokorny <ano### [at] anonymousorg> wrote:
> Thanks for the test scene. I've added it to a small collection of
> problem sphere_sweeps I have going. Also helpful to see you trying such
> a large value for tolerance and getting a better result. I'd always
> followed the documentation with respect to magnitude suggestions and had
> never seen tolerance affect much.
>
> Christoph backed out a fix in beta 6 which caused other problems but
> made sphere_sweep artifacts like yours better. I thrashed around in this
> code yesterday without much luck. Starting to think completely fixing
> things here may require changes in the core solver - that sphere_sweep
> issues might be tangled somewhat in the tiny discontinuities we see in
> other objects at times due scale and ray/surface/coordinate inflections.
>
> The great news is Christoph fixed ALL the sphere_sweep auto-bounding
> issues I have in hand in beta 6! The auto-bounding issue has dogged
> sphere_sweeps from day one with this object.

Good thing to hear that anyway.

I didn't have any luck using small tolerance values but I also didn't know it
defaulted to 0.000001, much less than I thought (by 1000 times!). Trying by tens
down to 0.00000000000001 got me nowhere!

On that subject, I found out the sphere_sweep surface will disappear at the
location of an artifact if the right number is used for tolerance. For example
48 or a little more like 48.1 to see it better, if scene file is unchanged from
that posted.
A scale of 1 instead should make same thing possible at about tolerance 3.905 or
so.

Rendering a good resolution size helps see that, too, such as 800X600. Lacks
shadows as-is so I guess it's like a CSG difference surface.

And I don't think this can work on every artifact location. Maybe only the
nearest to camera...?

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