Jump to content

Noise in waxwell renderings


brucehamilton
 Share

Recommended Posts

i've got problems with noisy renderings (after SL 18 and 15hrs) and did a lot of "scientific" research the last weeks, based on

many other similar bugs other maxwell users report in various forums.

 

- its not because of Caustics, I've turned them off (direct/indirect)

- its not because of pure white, I changed it to 240/240/240

- its not because of the Sun, I raised the amount of "Scattering Asymmetry" within the "aerosol properties"

- its not because of lights, i've rendered without every single light emitter a time

- its not because of bump maps or displacements, I've changed the materials

- its not because of indoor/glass, I removed the glass out of the window frames

- its not because of High or low roughness, I've no roughness 0 or 100 materials (anymore)

- its not because of low SL, the effect does not disappear at SL>18 and 18hs of rendertime

 

 

My feeling is, the effect is evoked when you have a very shining, especially white material (car paint) combined with bumped and/or displacement-mapped materials. The effect increases in indoor renderings, meaning when the sun has to come through windows.

 

any new ideas anywhere??

 

 

Maxwell render 2.0.3 used as a plugin from 3dmax 2010

System win7, 64 bit

Intel Core i7 3.4 GHz Prozessor

8,0GB RAM

Edited by brucehamilton
Link to comment
Share on other sites

Seeing an image would help diagnose the potential problem. The only thing that comes to mind that may not solve the problem but could help is that 240 white can still be a bit high. For the image below I used a value of 210 for the white drywall and the post processing is quite minimal.

 

25%20WatervillaDeOmval%20Interior%20Final%20-%20Low%20Quality.jpg

 

-Brodie

Link to comment
Share on other sites

Here comes my picture. SL=13, rendertime appr. 7 h.

No i'm expieriencing with network rendering.... 22hs and more

Its getting a bit better but it's so slow...

I would love to have a result like your wonderful picture some day!

thanx[ATTACH=CONFIG]47244[/ATTACH]

Link to comment
Share on other sites

3 things.

 

1) Maxwell can be a bit like a real camera in that with less light typically comes more noise. The reasons are completely different but it still holds true for the most part. With only the soft (presumably) HDR light coming in there's not a lot of light for Maxwell to bounce around and resolve that noise. I presume there should be some ceiling lights and maybe floor lights in there eventually? If done correctly those will help resolve that noise.

 

2) Can you do a screen shot or two of that material used for the ceiling. It seems to be your main culprit for collecting noise. I'll bet we could optimize it.

 

3) I assume the glass you're using is AGS?

 

-Brodie

Link to comment
Share on other sites

Hi Brodie,

1) I have floorlights on, ceiling lights are not planned ;-)

2) screenshot attached. in the meantime I changed down to 210 (looks not so nice...[ATTACH=CONFIG]47247[/ATTACH]) and raised the roughness radically.

3) Yes it is, i've read some posts about that...

Link to comment
Share on other sites

1) I don't know anything about he space but it seems like it will be quite dark if that's really all the lighting that's available. But if you can't add lighting, you'll just have to make due with longer render times.

 

2) What is the real world material that this Maxwell material is supposed to represent? The original render and this material seems quite glossy and it looks like you're using the layer structure from a plastic material made with the wizard? If it doesn't need to be glossy, try getting away with 1 layer or reducing the strength of the Top Coat significantly.

 

If you need to to be glossy and are having noise issues I've found that using a Coating rather than a second Additive layer clears up much faster. Both of the materials below are set to 220 and the Coating layer is just the default that comes up when you add a Coating.

 

[ATTACH=CONFIG]47248[/ATTACH]

 

210 can look too dark, particularly in a poorly lit space. It worked for me because I had a nice bright render with lots of light flooding in. I wouldn't go higher than about 235 though. Keep in mind that if it doesn't render as pure white you can always adjust the levels in PS later which is better than trying to fix noise issues.

 

Long story short, I believe your problem is a combo of lack of light and the particular material(s) where the noise is collecting. Focus on those 2 issues first and go from there.

 

-Brodie

Link to comment
Share on other sites

Thanx a lot, its really good to know, especially the thing with the two layers (I've read about before, tested ist and could'nt find such differences), also the lack of light is interesting, i wil try after returning from my one week skiing holiday......Yeahhh

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...