POV-Ray : Newsgroups : povray.binaries.images : Blob experiment - 160kb JPEG Server Time
14 Nov 2024 04:31:27 EST (-0500)
  Blob experiment - 160kb JPEG (Message 1 to 3 of 3)  
From: Stefan Viljoen
Subject: Blob experiment - 160kb JPEG
Date: 15 Nov 2009 04:03:13
Message: <4affc3d1@news.povray.org>
Something I rustled up a few days ago.

This is the scene that can "break" Pov by rendering completely black (if you 
turn off photons) or getting the photon step to go into an infinite loop (if 
you turn on photons) - if you set the stack of blobs in the middle to have a 
transparency of more than 0.3999999.

This applies to 3.6.1 on Linux (at least) and Megapov-1.2.1 on Linux, pre-
compiled and self-compiled with GCC version 4.4.0 20090506 (Red Hat 4.4.0-4) 
(GCC) on Fedora 11.

Anybody got any idea why only one of the three shadows to the left bottom of 
the blob stack is a colored shadow, while the other two are black? Trace 
levels?

Source in PBSF, except of course for the .ttf files for ttf objects in the 
scene.
-- 
Stefan Viljoen


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From: Alain
Subject: Re: Blob experiment - 160kb JPEG
Date: 15 Nov 2009 16:43:30
Message: <4b007602$1@news.povray.org>

> Something I rustled up a few days ago.
> 
> Anybody got any idea why only one of the three shadows to the left bottom of 
> the blob stack is a colored shadow, while the other two are black? Trace 
> levels?
> 
> ------------------------------------------------------------------------
> 

It hard to tell due to the reflection in the same area. Try with a 
non-reflective ground.

What is your max_trace_level? Any message about how many trace levels 
where used? If you have something like 15/15, you may need to increase 
max_trace_level.

I also see many specks everywhere, not just on the blobs. It suggest 
that you do need a larger max_trace_level.



Alain


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From: Stefan Viljoen
Subject: Re: Blob experiment - 160kb JPEG
Date: 16 Nov 2009 12:17:54
Message: <4b018942@news.povray.org>
Alain wrote:

> Stefan Viljoen a écrit :

> It hard to tell due to the reflection in the same area. Try with a
> non-reflective ground.
> 
> What is your max_trace_level? Any message about how many trace levels
> where used? If you have something like 15/15, you may need to increase
> max_trace_level.
> 
> I also see many specks everywhere, not just on the blobs. It suggest
> that you do need a larger max_trace_level.

Yes, the specks bothered me too. I tried a higher trace level shortly after 
posting the image, but once again it just turns the entire image output 
completely black... a different manifestation of some kind of error with 
blobs?

*sigh*

Thanks anyway!
-- 
Stefan Viljoen


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