[Radiance-general] Re: Radiance-general digest, Vol 1 #393 - 1 msg

Tue, 04 Nov 2003 14:06:30 +0000

Dear Mark

I would greatly appreciate if you could show me as to how to make these 
changes.

Thanks

Marcus

>Date: Mon, 3 Nov 2003 11:05:03 -0500 (EST)
>From: Mark Stock <[email protected]>
>To: [email protected]
>Subject: Re: [Radiance-general] Metal Reflection Problem
>Reply-To: [email protected]
>
>Marcus,
>
>I think the "fractal pattern" you refer to in the specular
>highlights can be solved by turning on Radiance's pure Monte-
>Carlo sampling algorithm (requires re-compiling, though).
>I read about it in a text file on the old Radiance site:
>
>----------
>RADIANCE Compile Switches
>
>Here is a list of compile switches, used to customize Radiance code for
>specific machines and users:
>
>-DMC
>     If set, switches from default low-discrepency sequence sampling to
>true (pseudorandom) Monte Carlo.  Use if the "brushed" appearance of
>specular highlights and penumbras bothers you.
>----------
>
>To get this to compile with the HEAD distribution, you need to
>make a few changes to the src/common/random.h file. I can give those
>to you if you like.
>
>also...
>
>On Mon, 3 Nov 2003, Roland Schregle wrote:
>
> > Marcus Jacobs wrote:
> >
> > > As a side note, the reflections of the light sources on the floor do 
>not
> > > seem right. I have noticed this before. Does anyone know what's 
>causing
> > > this?
> >
> > Don't seem right as in no penumbrae? That's expected for a solar source
> > modeled with the SOURCE primitive. AFAIK these sources are immune to -dj
> > and -ds anyway. Maybe a Fully Licensed Guru[tm] here can tell you more.
>
>I've found that -dj works with the "source" primitive (again, I
>use the HEAD distro, but I found it to work in the 3R5 distro, too).
>It uses the last float argument, the angular disc size, to determine
>the jittering. Go ahead and raise that from 0.5 to 5 degrees for an
>unrealistic sun with nice-looking soft shadows.
>
>I typically use -dj 0.6 to 0.7 for most of my scenes.
>
>BTW: the soft shadows will exhibit the same fractal-like pattern
>that you see in the specular highlights. -DMC cures this, too,
>but can require higher-resolution runs before filtering down.
>
>Oh, and -ps 1 is almost a necessity with -DMC turned on.
>
>Mark
>
>
>--__--__--
>
>_______________________________________________
>Radiance-general mailing list
>[email protected]
>http://www.radiance-online.org/mailman/listinfo/radiance-general
>
>
>End of Radiance-general Digest

_________________________________________________________________
Great deals on high-speed Internet access as low as $26.95.  
https://broadband.msn.com (Prices may vary by service area.)