Grain in murky water

[Matt]

I'd think that RTE + AA 6 should be sufficient to remove any subsurface noise. If it's not, can I see a TGD?

Here is the TGD I'm testing in. Another thing I notice is water displacement turns into a polygon show. x.x

The noise Ulco is talking about occurs when an object casts a shadow into the volume. Your scene doesn't have any of that. With Ulco's scene this technique should remove the noise he had.

The reduced micropolygon resolution is because of the default "Ray detail multiplier" of 0.25. You can control this using Subdiv Settings on the Advanced tab. Normally this only affects shadows, reflections and transparency rays, but when you enable RTE it affects primary rays too.

[WAS]

I'd think that RTE + AA 6 should be sufficient to remove any subsurface noise. If it's not, can I see a TGD?

Here is the TGD I'm testing in. Another thing I notice is water displacement turns into a polygon show. x.x

The noise Ulco is talking about occurs when an object casts a shadow into the volume. Your scene doesn't have any of that. With Ulco's scene this technique should remove the noise he had.

The reduced micropolygon resolution is because of the default "Ray detail multiplier" of 0.25. You can control this using Subdiv Settings on the Advanced tab. Normally this only affects shadows, reflections and transparency rays, but when you enable RTE it affects primary rays too.

I had to remove my shark object as it's not shareable. You could use a sphere.  Second park makes total sense, I had thought of increasing that too to see if it helped.

[Dune]

I have to test your setup`on my other machine, but I don't think translucency works if the color of the default is black. I used at least a very dark color (0.01). Further; if you input the water shader into the default, the merge will double the waves, but that's an aside. And does transparency of 2 add to a transparency of 1 (which I believe would be 100%)?
Anyway, nice to give water another shake.

[WAS]

I have to test your setup`on my other machine, but I don't think translucency works if the color of the default is black. I used at least a very dark color (0.01). Further; if you input the water shader into the default, the merge will double the waves, but that's an aside. And does transparency of 2 add to a transparency of 1 (which I believe would be 100%)?
Anyway, nice to give water another shake.

Since the mix is 0.5, you actually would get half the wave height without mixing with itself 0.5 + 0.5  = 1. Specifically why I added that input.

Additionally yes, translucency like I mentioned is just not there. Only for light. It would be super helpful if the default shader could have it's colour disabled and act somewhat like a surface layer and just be translucent. I'd imagine in that event it may help, but may also just bring back the fuzz problem.

This fuzz also seems to be present in shadowed reflections I've noticed when testing the reflections on spheres.

[Dune]

You're right. If displacements are added, it would be 1+0.5 though.

I wondered about the transparency above 1, and indeed it is not 100%. Pulling it even higher has some strange effects, interesting.

I made a comment about color disabling in default shader somewhere too, would indeed be very handy (if translucency would then still work in water shader).

Turning off shadows of the sharks was the easiest way to get rid of the grain, btw.