Underwater caustics flicker

[devailo]

Hello, i'm doing an underwater scene with environment fog and caustics. Somewhere i read that caustics wont work correctly with the environment fog but i font get much better results without the fog and its also a needed effect. Could it be something in the settings? Here is the video with the flicker and the settings:

https://vimeo.com/230760335

Also the water is a plane facing downwards because if it faces upwards its not transparent for some reason and it doesn't reflect anything. If a "shell" it the water looks amazing but the caustics deform and almost disappear and the render time becomes unbearable.

[Morbid Angel]

I wouldn't use vray lights as they would produce soft caustics. Just use regular directional or spot light. You need to set the caustic subdivs really high like 15000, or 25000 to get solid caustic pass.