POV-Ray : Newsgroups : povray.binaries.images : Having a try at light distributions : Re: Having a try at light distributions Server Time
3 Jul 2025 01:13:54 EDT (-0400)
  Re: Having a try at light distributions  
From: William F Pokorny
Date: 15 May 2019 10:04:13
Message: <5cdc1c5d$1@news.povray.org>
On 5/13/19 7:29 AM, Jasper wrote:
> Hello everyone!
> 
> I am trying to introduce photometric data files of luminaires (i.e. IESNA .ies
> or EULUMDAT .ldt) in Povray to get "correct" lighting distributions. This
> currently works by combining
> 
> (1) a point light source
> (2) a sphere with radius 0.01 and spherical mapping of an image map (.png with
> the alpha channel used for transparency) which represents the lighting
> distribution for different angles.
> 
> However, for large coordinates (e.g. 1e+6), I get unwanted black spots in a
> regular pattern (see attached image on the left).
> 
> Jasper
> 

Hmm, I have to say I'm curious about the regularity of those black 
spots. The numerical issues I've hit are usually noisier - or completely 
black/invisible/something when a hard numerical limit is hit.

Any chance I could get a smallish test case posted to one of the scene 
file groups? I'll stick it in my POVRay_Issues directory and at least 
take a quick look if not now a deep one.

Bill P.


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