Glass and Liquid rendering problem

[jwrockstarr0]

I have a very simple beer bottle file, with only two bodies, that seemingly refuses to render properly. Now the bodies won't take any material. All I want is a transparent bottle and transparent beer. 

I haven't used Fusion for a while so it must be something simple...

[TrippyLighting · Accepted solution]

The trick is to make the two volumes overlap and then use the "dielectric precedence control" to give one of the materials higher precedence.

[jwrockstarr0]

Peter, that's certainly not intuitive and not something I would have figured out. But whatever works...

Thank you!

Jay

[chrisplyler]

I've never played with the dielectric precedence control. What does it actually do?

I've been able to render a container of liquid, without overlapping the two bodies, and without using that dielectric precedence control, simply by applying suitable materials or appearances.

I think the issue the OP had was simply that materials and appearances can only be separately applied if the two bodies are actually separate Components. In the OP's picture, there were not separate Components, but only two bodies in the same Component.

[TrippyLighting]

Rendering 2 volumes with an infinitely thin boundary more often than not will create rendering artifacts when you use refractive/dispersive materials. The two volumes will start Z-fighting at the interface where the tesselation of the 2 objects is usually not 100% the same.

When you are overlapping the volumes that interface problem is solved, but then you need to tell the render engine what material takes precedence in the area of overlap. That is what the dielectric precedence control is for. This goes back to a pretty old white paper (introduced a Siggraph I believe) and is used in other render engines as well.

[chrisplyler]

Thank-you for the explanation. I swear I learn more new stuff just interacting with you occasionally than from all the college professors I ever had.