[Radiance-general] high reflectance & roughness metals

[Ignacio Munárriz]

and a more smoother result is achieved using urand in rv[0]
rv[0]=urand(ilhash(dimlist,ndims)+samplendx);

rv[1]=frandom();

http://www.alfanature.com/avis/exter3.jpg

----- Original Message -----
From: "Ignacio Munárriz" <gvn at retena.com>
To: "Radiance general discussion" <radiance-general at radiance-online.org>
Sent: Tuesday, March 01, 2005 11:20 AM
Subject: Re: [Radiance-general] high reflectance & roughness metals


> I was disturbed with the horizontal lines that was present in the metal
> http://www.alfanature.com/avis/exteriore3b.jpg
>
> son i took a look at the code normal.c, first discovering that the random
> functions
> lrand48(), drand48() in random.h
> did not work in my computer (return always 0), so i changed them for:
> #define random() rand()
> #define srandom(s) srand((unsigned)(s))
> #define frandom() (random()*(1./2147483648.))
> then random works but continued with the artifact, then i changed normal.c
> in this way:
>
> instead of multisamp(rv, 2, d);
> rv[0]=frandom();
> rv[1]=frandom();
>
> i think that multisamp creates a pattern in the random because the randoms
> numbers i got were rare( some too exacts .50000 0.00000 .7500000)
>
> and the result is
> http://www.alfanature.com/avis/exter.jpg
>
>
>
>
>
>
> ----- Original Message -----
> From: "Gregory J. Ward" <gregoryjward at gmail.com>
> To: "Radiance general discussion" <radiance-general at radiance-online.org>
> Sent: Friday, February 25, 2005 6:24 PM
> Subject: Re: [Radiance-general] high reflectance & roughness metals
>
>
> Hi Ignacio,
>
> If you prefer standard Monte Carlo sampling over the low-discrepency
> method, then you should recompile with -DMC as a flag in your rmake
> script.  The only way to reduce the noise is to increase your sampling
> density (initial rendering resolution).
>
> -Greg
>
> > From: Ignacio Munárriz <gvn at retena.com>
> > Date: February 25, 2005 12:40:40 AM PST
> >
> > hi, althought i guess it has been discussed already at the forum, i've
> > having some problems with high reflectance & roughness metals to
> > simulate a
> > diffuse   metal (alluminium) garage door
> >
> > ...
>
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