POV-Ray : Newsgroups : povray.advanced-users : Photons, in version 3.6 to 3.7 : Re: Photons, in version 3.6 to 3.7 Server Time: 18 Jun 2019 04:43:22 GMT
  Re: Photons, in version 3.6 to 3.7  
From: William F Pokorny
Date: 9 May 2019 13:02:43
On 5/9/19 4:53 AM, Albun wrote:
> 
> So, with or without macro, with no_image the render do the same result, and no
> photons count in 3.7.
> 
> Who can tell better ?
> 
> Thanks all
> 
> Albun
> 

It happens I've been working some in the photon code for another 
investigation so I started to dig here. I have to take a short break but 
what I've found so far is that having the no_image or not changes 
whether the following test:

if (Test_Flag(bestisect.Object, PH_TARGET_FLAG))

in PhotonTrace::TraceRay in photons.cpp is true.

I thought, OK, it must be a parser issue and started to look at things 
from that end. But, the sphere's PH_TARGET_FLAG is true with and without 
the no_image flag checking just after the

Parse_Object_Mods(reinterpret_cast<ObjectPtr>(Object));

call in ObjectPtr Parser::Parse_Sphere() in parser.cpp.

So... I still don't know what's going on, but looking like the sphere's 
photon target flag is changing state sometime after being set correctly 
in the parser and before the photon TraceRay call due the no_image modifier.

More when I get back to it - unless someone beats me to it.

Bill P.


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