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
my first atempt:
rpict -x 4000 -y 3000 -vf vistas/e3 -af ambext -ab 2 -ad 200 -as 30 -ar
300 -sj 1 -st 0 -dj .5 -pj .5 -t 60 exterior.oct>img/exteriore3.pic
pfilt -r .6 -x 800 -y 600 img/exteriore3.pic>img/exteriore3pf.pic
with the material
void metal jaimito_l_3dpgaraje
0
0
5 0.65 0.65 0.65 0.5 .1
and the result is
http://www.alfanature.com/avis/exteriore3b.jpg
as you can see there are some artifacts (horizontal bands) , are them due to
low-discrepancy?
the second attempt is using pure montecarlo
void texfunc metro
4 gloss_dx gloss_dy gloss_dz gloss.cal
0
3 .02 .02 .02
metro metal jaimito_l_3dpgaraje
0
0
5 0.65 0.65 0.65 0.5 0
and the result is
http://www.alfanature.com/avis/exteriore3.jpg
any way to improve that?
anyway i prefer pure montecarlo to default radiance, do you?
in other threads it was recommended to decrement sj and increment st, but
this isn't it a way to elude the problem?
thanks all
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@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
...
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@gmail.com>
To: "Radiance general discussion" <radiance-general@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 Mun�rriz <gvn@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
...
_______________________________________________
Radiance-general mailing list
Radiance-general@radiance-online.org
http://www.radiance-online.org/mailman/listinfo/radiance-general
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 Mun�rriz" <gvn@retena.com>
To: "Radiance general discussion" <radiance-general@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@gmail.com>
To: "Radiance general discussion" <radiance-general@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 Mun�rriz <gvn@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
>
> ...
_______________________________________________
Radiance-general mailing list
Radiance-general@radiance-online.org
http://www.radiance-online.org/mailman/listinfo/radiance-general
_______________________________________________
Radiance-general mailing list
Radiance-general@radiance-online.org
http://www.radiance-online.org/mailman/listinfo/radiance-general
