glowing eyes make colour blotches, Iray

Linwelly

Reposting this from my art thread, with the hope that here are some specialists who find a clue

for this guy I made the eyes a bit glowy by putting the original Iris colour map into the emissive and add a red tint to it. this was rendered beginning of June and here everythign is working still fine.

This image has been resized to fit in the page. Click to enlarge.

 

Now I want to use the guy some more and suddenly I got huge problem with tha glow: The rim of the Irisis make stupit blotches of red ( when I activate spectral rendering in all kinds of colours) and they don't resolve when rendring far into the iterations. I've tried moving the light so that he's mostly in shadows again, I deactivated the share glossy input for the Iris and some other things, nothing chaged. I do have the suspicion that it started with the Iray update but I can't point my finger on the cause. So if someone has an idea, please help, I want to use this guy again!

Thanks for all input!

AndyS

Hi,

possibly some result of a new iray version?
Please check Eye Moisture, Cornea, Sclera settings.
If those are OK, create a bug report.

Linwelly

Thanks for the pointers, those after all were perfectly ok, but I found that I had the caustics left active, after turning them off everything worked accordingly.

Though now I wonder why the caustics are so crude in the reaction. some testing time needed I guess.

AndyS

Caustic?

Normally shouldn't cause such strange effects. But the caustic sampler is important for supporting re-reflect reflected light. And of cause dispersion as a part of refraction.
So it is possible your effect results out of the glossy reflection between iris, cornea, sclera, eye-reflection and eye-moisture. You may get a multi-reflection of you glowing iris between all these layers.

Try to turn off the glossy reflection for all layers below the "real" eye's reflection.