Blochy resault with Refractive GI caustics

[Numse]

This week I got to do 2 interior shots at work, both bathrooms. One was a nightshot and one was a dayshot. I began with the nightshot and got huge problems with blochy renders when I had the showerlighting on (it´s a steamer with glasswalls and spotlights). I tried to shut down refractive GI caustics in my GI settings and got rid of the blochyness, and the resault seemed to be the same. When I moved on to the dayshot today I used the same rendersettings and noticed that the glass on the steamer threw pretty dense shadows, so I enabled refractive GI caustics again and the problem was solved.. but I´m back with the old problem, blochyness when to much light travels through the glass. Anyone got a solution?

[vlado]

There is probably some small bright spot that rays going through the glass hit from time to time. It might be a light that is very close to a white surface, or a self-illuminated material, or a HDR environment, or the VRaySun (but I assume it is not the sun, since you mentioned a night shot).

It might help if you turn on photon-mapped caustics, but disable the caustics for all lights in the scene from the V-Ray light settings dialog.

Best regards,
Vlado

[Numse]

Thanks vlado, I´ll try it out today

[Numse]

Hey, I´ve tried the solution and this is what I came up with..

Now, first I tried the night scene. First render in the attached jpg is with my default setting, Refractive GI caustics ON, Vray light caustics ON, photon-mapped caustics OFF. The light and shadows seems fine, but with the same settings for the night shot, where I use alot of vray lights in the steamer, it doesn´t work because of blotchyness in different parts of the scene. So, I tried turning off Refractive GI caustics (render 2) and the blotchyness in the night shot was gone, but shadows behind the glass became more dense, as shown in the daylight shot. After this I posted this thread, and got the answer from you vlado, and now I´ve tried some other solutions as shown in the attached image. It seems that turning OFF vray light caustics and turning ON photon-mapped caustics, as you proposed, gets rid of the blotchyness but the shadow becomes darker.. I also tried turning ON vray light caustics and photon-mapped caustics in both scenes, and in the night shot it just didn´t work. With default photon-mapped caustics settings and low settings overall it just ate my 2*quadcore pc totally.. auch..

So.. what to do? :/

Another question. how come turning ON photon-mapped caustics "work" when I have turned OFF all caustic photons emitting from the lights?