[Mihai]

If it's only sun and sky, you get lots of indirect lighting in this image, and that's a situation which will take a lot longer to get a clean image. But I've also seen that physical sky lighting is slow in interior renders, especially with small openings for the light to shine through and so lots of indirect light. Could you try the same scene but lit with an hdr instead of the physical sky? Would be interesting to see a comparison.

[Mihai]

It's possible directly, set sky to environment and load your hdr in all channels. You have to use a lat/long format hdr map, not probe or cross format.

[grupo4]

I made a cooperative test with 5 machines and multilight.
I let them render for 20h an they all reached sl 12 (1024x768). After the render I merged them manually and in the two posted results you can see, that one is with just sun and sky and the other is just with the 6 emitters.

Just sun and sky


Just emitters


As you can see the emitter version Is almost noisefree and the sun and sky version is very noisy. Why is this? I think, that this noise never goes away! Can you give me a hint about material settings with a texture map optimized for not having too much noise.

How dou you merge the images manually

[Tim Ellis]

I've found the same with a test scene that should only use sunlight to light the scene.

This is the scene, a merged manual co-op (on the same machine, each @ 800x600 sl11-13 after about 2hrs).
In my initial render with just physical sky & sunlight, the noise had no sign of clearing even after 9hrs @ sl 17, the following is the merged coop with an emitter behind the camera, which improved noise reduction in the darker areas, but not by much.




The only thing I didn't check was the scene scale, so perhaps this is incorrect and is thusly increasing times for noise reduction.

grup04, to manually merge mxi files, render out several versions of the same scene and save each one as an mxi from inside mxcl.

Then use merge coop from the mxcl file menu, select the mxi files to merge, then create the name for the merged file and that's it.

Reopen this new mxi in mxcl and save image as a jpg, tga etc, from the file menu.

Hope this helps,

Tim.