POV-Ray : Newsgroups : povray.beta-test.binaries : Radiosity POV 3.6 vs. 3.7 vs. MCPov : Re: Radiosity POV 3.6 vs. 3.7 vs. MCPov Server Time
23 Feb 2024 21:47:16 EST (-0500)
  Re: Radiosity POV 3.6 vs. 3.7 vs. MCPov  
From: Ive
Date: 18 Jan 2009 17:17:25
Message: <4973aa75$1@news.povray.org>
clipka wrote:
> Impressive scene!


> Comments to the pictures:
> - Render times?

~2h for 3.6
~1h for 3.7
~20h for MCPov

I'm currently rendering a 3.7 version with higher quality settings and 
will show it when it's finished.

> - The MCPov shot looks most convincing, no argument here. However, it is not
> perfectly clear whether this is due to an actual superiority in quality, or
> imperfections in the POV 3.6/3.7 material setup. Especially a look at the
> mirror raises suspicion: While it is rather dull in the MCPov shot, it seems to
> be plain 100% reflective in the POV 3.6.1 and 3.7 shots. So there must be *some*
> difference in material settings.

I have no explanation why the reflection in the mirror looks different 
in the MCPov version. And in fact it makes me quite unhappy, it looks 
somewhat desaturated. But believe me, the material used for the mirror 
is in all shots exactly the same. The only difference in the materials 
are the woods for the chairs, the viol and the mirror frame where the 
MCPov version makes use of the MCPov blurred reflection feature where 
the 3.6/3.7 versions use averaged normals to get some highlights.

> - The 3.6.1 shot looks rather dark; I attribute this to the windows and flaws in
> POV 3.6 radiosity: When gathering deep-recursion samples, POV 3.6 effectively
> just traced a single level, so I guess it will not make it through the windows.
> All 3rd-bounce samples will probably be pitch black, and possibly even the
> 2nd-bounce ones.

In fact there is NO window "glass", there is just empty space ;)

> - The 3.7 shot indeed looks weird - but this weirdness look distinctively
> familiar: "Ambient" immediately comes to mind. It looks very much like you
> forgot to set all materials to "ambient 0" (or, alternatively, turn down the
> "ambient_light" to something like 0.001 and multiply your sky ambient by 1000;
> usually this sufficiently dims the ambient terms and saves you a lot of work.)

Nope. All materials do use ambient 0 in the finish statement and no 
default include files are used where something else might be specified.

> That link only leads me to the p.b.i. overview.

Sorry. This should work:



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