iray/lighting

Sosk

hi everyone.  I'm pretty new to 3D but have learned a massive amount in the last year.  Most problems ive encountered I've managed to work through successfully. This time I need help. Using Iray to render is consistently giving me scattered color/light particles in the shadow areas of skin rendering and nothing I try seems to remove them. I've attached a pic to show what I mean.  Over to the experts.

BeeMKay

Have you tried enabling the noise filter in the Render Setting? (Filtering --> Noise Filter Enabled)

It looks like it needs to render a lot longer. As a rule, the less light (in terms of lumiance) there is, and the darker the shadows are, the longer the render time needs to be.

Try increasing the render settings under "Progressive Render" gradually.

You can also try and give the front side a bit more light, by using a HDRI with a very low Environment Intensity setting.

 

Tobor

lee_lhs said:

Have you tried enabling the noise filter in the Render Setting? (Filtering --> Noise Filter Enabled)

Just as a BTW, that noise filter is only for renders you intentionally want to cut short before full conversion. It resolves some convergence noise issues but only at the beginning of the render. In fact, if you use the filter (called degrainer), look at your log, and you'll see Iray threw an internal error that the filter is not compatible with the pixel filters further down in the Filtering list. The pixel filters do their work toward the end of the render, as more and more samples converge.

For the OP: You *might* have some success turning the Architectural Sampler on (see the Optimization sub-panel). This sampler is a "helper" for light situations where the majority of the light is indirect, with areas in significant shadows. Just be aware that your renders will take a long time in any case. As noted in the reply above, you probably need, at the very least, extend the amount of time beyond 2 hours. How long depends on your hardware, of course. On my machine, I could let a render like this go for 10 hours, and it would still have the noise.