Two problems I have to solve. First cloud. I wanted to have a cloud with shadows of surfaces turned on, but I can't seem to get rid of a certain grain. It is less with shadows turned off, but that is not really what I wanted. The sky is a starry background, btw. There's a reflective shader in the rock, so I thought that may cause some grain, but turning that off does not erase the grain.
It's only primary cloud, btw. With mpd 0.6 and AA6, and cloud quality on 4! I thought it shoud be rather smooth. Anything else you guys can think of?
Second is a card. I add some fractals to a surface shader, masked by simple shape and UV mask to keep the whites to the center, and with an opacity mask (default shader) to be sure, and also a non-reflective glass shader preceding the surface shader. Still I get this darkened rectangle. It does not seem the case in default render.
So, how can I get rid of that dark glass? I didn't change the RDM, btw, but that would only work on the details I thought, and the whites being smoke, it might as well be a little blurry. But not dark.
Some more information. I used the robust sampler, default settings, DOF is on, soft shadows by default too.
In the last row of tests, you can also see that PT does something dotty to the rock, which is not the case in the deferred render. I'm pretty sure it's the little bit (0.1) of (non-RT) reflection I put on the rock. But I do not like it. So I should probably turn that off if I want to render this in PT mode. Any thoughts?