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Strange noise
Posted: Tue Mar 13, 2012 11:24 pm
by jespi
Hi everyone,
Could someone take a look at the attached screen shot
http://dl.dropbox.com/u/26415033/Screen ... 0%20PM.png
As you can see there is odd noise on the wood facade and the higher the sample level is the strongest the noise. It is a simple scene and I can not see any object generating caustic or whatever. Thanks in advanced,
josé
Re: Strange noise
Posted: Tue Mar 13, 2012 11:31 pm
by Half Life
To me it looks like you may have 2 separate faces with different materials in the same spot there.
Best,
Jason.
Re: Strange noise
Posted: Tue Mar 13, 2012 11:47 pm
by jespi
Thanks Jason!, but I've rechecked the geometry and there is not duplicated geometry. If you take a look at the preview, the same noise is going to appear at the left side of the brick facade.
Re: Strange noise
Posted: Tue Mar 13, 2012 11:50 pm
by Bubbaloo
You can see it's showing up on the brick too (see the preview image). Looks like specular reflections from the sun. Maybe you have some unrealistic reflectivity in the materials? Do you have an additive layer with 0 roughness?
Re: Strange noise
Posted: Tue Mar 13, 2012 11:57 pm
by jespi
Re: Strange noise
Posted: Wed Mar 14, 2012 12:31 am
by Fernando Tella
Could you temporaly remove the maps of the first BSDF, all of them, and then check again? Maybe it is just a highlight affected by all the maps of the reflective BDSF.
Re: Strange noise
Posted: Wed Mar 14, 2012 12:35 am
by m-Que
Hmm....
Is that a cutout/2D or a 3D tree?
Re: Strange noise
Posted: Wed Mar 14, 2012 12:37 am
by jespi
m-Que wrote:Hmm....
Is that a cutout/2D or a 3D tree?
A cutout 2D tree in .png format, why?
Re: Strange noise
Posted: Wed Mar 14, 2012 12:39 am
by Bubbaloo
I can look at the MXM if you want to "pack and go", and PM me a link.
Re: Strange noise
Posted: Wed Mar 14, 2012 12:41 am
by m-Que
Oh,
I had a similar problem - when rendering with alpha channel enabled, using a 2D .png tree, some weird noise would appear.
But as long as I turned alpha channel off it would disappear.
Perhaps, you could do a quick render without a tree...
Re: Strange noise
Posted: Wed Mar 14, 2012 12:51 am
by jespi
Fernando Tella wrote:Could you temporaly remove the maps of the first BSDF, all of them, and then check again? Maybe it is just a highlight affected by all the maps of the reflective BDSF.
Thanks Fernando!, As you can see from the screen shot your solution seems to work, now the wood facade does not show any noise. So now the question is why?. I'm going to deactivate the trees as m-Que suggest and see what I get.
Thanks guys!
Re: Strange noise
Posted: Wed Mar 14, 2012 12:55 am
by jespi
Re: Strange noise
Posted: Wed Mar 14, 2012 1:13 am
by jespi
Well, I've tested disabling Alpha Channel and also turning off the cut out trees as m-Que suggested with no success. So, for now the only work around is disabling reflective layer, but this is not a solution.
Brian, I can send you a link to the mxm but I need your mail in order to send you the DropBox link.
Thanks a lot for your help!,
josé
Re: Strange noise
Posted: Wed Mar 14, 2012 1:23 am
by Fernando Tella
I don't think it's a bug. I think the key of the problem is in the lightness/darkness of the maps applied that are creating an strange colouring of the highlight of the sun.
To create a nice wood I suggest to, on that BDSF, just map the roughness and leave refl 0º to mid grey, refl 90º to white and Nd around 1,7
I guess you are having a similar problem (excess of mapping

) in the brick material.
Re: Strange noise
Posted: Wed Mar 14, 2012 1:27 am
by m-Que
Btw, in your last screenshot, the noise is still visible in preview window on the the brick wall, so perhaps there might be something else.