Jump to content

Noise on large white surfaces


hereagain
 Share

Recommended Posts

I'm rendering a gallery interior where white walls and a polished white floor are being used. No matter what I do, I just can not get rid of the noise that is occuring on these surfaces. I have have upped the multipliers on the scene lights as much as I can without burning out the room. I'm not sure what setup of primary and secondary GI engines is best for this particular scene, but listed below is what I currently have set up. Any help would be greatly appreciated.

Scene Setup:

Lights - vray sun at .003, vraylight above the entire interior at .6 with no decay and a fill light behind the camera, again with no decay at .3

Materials – the floor is a vraymaterial, RGB of 240,240,240, Refl. Glossiness of .7. The display wall is the same, except the glossiness is 1.0.

Render Settings

Image Sampler: Adaptive Subdivision, Antialiasing Filter on, size 1.5.

Adaptive Subdivision Image Sampler: Min rate -1, max rate 2. Clr threshold .1

Indirect Illumination: on, Primary Bounces (Mult. 1.0, Irradiance Map) Secondary Bounces (Mult. 1.0, Quasi-Monte Carlo).

Irradiance Map: Basic Parameters (min rate -3, max rate 0, Hsph 50, Interp. Samples 50) Everything else is at default settings.

Quasi Monte Carlo: Subdivisions 8, Secondary Bounces 5

rQMC sampler: Adaptive amount .85, noise threshold .01, min samples 8, global subdivision multiplier 1.0

Link to comment
Share on other sites

Put your Noise threshold at .001 instead of .01. You don't need your Hsph at 50 or your Interp. Samples at 50, try 30 and 20. What filter are your using? Try Catmull-Rom. Did you ever think of using Lache Cache for your second bounce? It gives great results.

Link to comment
Share on other sites

Joe,

 

Thanks for the tips. I'm waiting for another render to finish, then i'll go back and decrease the noise settings and repost. I have tried the Light Cache on several renders, and I see people on here raving about it all the time, but I have never noticed a decrease in render time or a noticeable increase in quality vs. QMC. Maybe I just don't have my settings optimized, I'll have to look into it.

Link to comment
Share on other sites

Sorry I haven't been able to get back to this till now...been a bit busy. I did try what Joe mentioned - dropping the Hsph to 30 and Interp to 20, tried noise at .005 and .001 with very little improvement and a big jump in time. Not sure what else I can do. In the meantime i've just changed materials; cheating I know, but this is due tomorrow. I'll update if I get a chance to fiddle with it some more. Thanks for the help.

Link to comment
Share on other sites

Hi Wyatt,

 

How many samples for the Vray lights? I'm sorry, I don't have vray in front of me right now to check the parameter names. I think the default setting is 4 or something, try 12. Also, if there is glass in any windows or skylights, exclude it from GI (right-click Vray Properties).

Link to comment
Share on other sites

I think Fran is on the right track. The noise is caused by the large vray light over the interior. At the default level, that light isn't generating enough samples for smooth lighting for that size of a light. So either increase the subdivisions for the light or, for faster renderings but not as good detail, check "store with irr map" on that light.

 

Also, if you are working with Vray 1.5, not 1.47, then your QMC Noise Thresh shouldn't go much below the "new" base setting of .01. They reset those values so you are effectively not using as many decimal places.

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...