opacity bug?

[Dune]

Did I stumble upon an opacity bug in 4.4.19? Default color is black, opacity input masks out all except distant SSS, preview doesn't indeed show anything close, but render is very different! Can anyone confirm? I will check it out again today.

[Matt]

At the moment (v4.4), opacity doesn't work on displaceable micropoly surfaces when using "Defer all shading" (or path tracing) because the shaders are not evaluated when the micropoly buffer is generated. I will get this working in a future update.

If your only reason to mask the water is to make it render faster where it is hidden, there is no point in doing this with deferred shading because it's not shaded where it's not visible.

[WAS]

I was actually hoping to mask out the water surface poking through the main surface because of small divots in the terrain. Masking the waves smoothly out is a bit of a pain and I had hoped to just use a hard mask at the water line level and just make the water inland not there

[Matt]

You could displace the water downwards so that it's not visible. With deferred shading that will be as fast as any other method, as long as the displacement is gradual, not abrupt.

[WAS]

That makes sense. 

Dune is your surface just one solid surface? It seems what is showing isn't totally solid. Is the horizon, what isn't supposed to be masked brighter/harder?

[Dune]

Thanks Matt, I'll keep that in mind. I wanted to get rid of water in a valley, so I have to do that differently. And yes, WAS, it's all one sphere.