On 5/15/19 3:36 PM, Alain wrote:
> Le 19-05-15 Ã 10:11, William F Pokorny a Ã©critÂ :
>> On 5/13/19 1:56 PM, Norbert Kern wrote:
>>> "Jasper" <nomail@nomail> wrote:
>>> OK, this doesn't have anything to do with radiosity - so I agree on
>>> point precision issues as cause...
>> Is this still true for you with recent v38 releases?
>> I'd captured the case(s) you posted a couple years back - my notes say
>> in 2016. I wasn't able to run what you posted directly on my little
>> machine, but a cut down scene was fixed when I tested a v3.71 branch
>> March 17, of 2017.
>> Bill P.
> The version don't matter when you hit the FPU's limits.
True. However, the reason I was digging into Norbert's particular
radiosity normals issue is that I intended to open up a github issue for
it so we didn't lose track of it.
My view is that unlike other places in POV-Ray where we hit numerical
issues, really tiny normals should just be treated as zero normals / no
normals - or perhaps be normalized somehow so they don't cause issues.
Probably good too if 'bad' normal scalings can be detected and the user
warned before they get ignored - but that's probably hard to the point
of being practically impossible.
In any case I didn't think his situation should be causing artifacts
like we were seeing in the output image.
The scaled very tiny normals were causing issues with Norbert's original
renders in 2016. When I looked at the issue in 2017 to create a github
issue, it looked like the issue had been fixed. The complication was the
original scenes as posted - I think even one smaller one posted later -
were too costly for my little machine. So, I evaluated behavior on
something I thought similar hoping to use it as the scene for the issue.
I might have gotten something wrong. I might have done something which
caused the issue to be there in (v??? don't remember) and gone in the
3.71 version I was testing against.
If Norbert still sees black spots with his original scenes using a
current v3.8, the issue still exists and I think we should open a github
issue for it. It's on my list again to try and run one of his originally
posted scenes again with v38 - but I'm in the middle of several other
projects and that won't happen for some time.
Suppose I'm hoping for a quick - "Oh, it works OK now" - answer/status
from Norbert to save some time! :-)
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