strange moire artifacts

[NooM]

Hi,

We have some very strange moire artifacts in our renderings. It has nothing to do with *.jpg compression it looks same as a uncompressed *.tif right out of the renderer.

Any idea?

thx NooM

[joconnell]

Are you using adaptive subdivision aa? It might be that there's very little difference in some of the shading tones on the wall and it's being undersampled together. More than likely though it's a limitation of using an 8 bit file - there isn't enough subtlety available in the file format to properly display the render. Try rendering to a 16 bit file format (tif, png, exr) or if you can't re-render the typical way to deal with this (it often happens colour correcting things like skies) would be to blur it in a 16 bit compositing workflow or add a small amount of noise - it seems counter intuitive adding noise back in but it'll break up the banding on the edges if used subtly and stop your eye from being drawn to them as much.

[Paul Oblomov]

Is there any lights ? Lower the cut-off tresh.. maybe this will work.

[vizualfx]

I have experienced the same thing. Are you working in a LWF?

It seemed to be caused in areas of very low light, and Vray struggles to differentiate what is light and what is dark.

Are you using LWF..? I think I may have helped it by burning the 2.2 into the image, rather than using a colour correct curve..