SSS behaving bad.

[quizzy]

3dsmax 2020, corona 6

the SSS is not transfered from one object to another object. I have several boxes with boxes on top. But when the topbox is a different material as the lower box, the SSS stops working.
See attached image. the top three boxes have a thin box on top, the lower one has not.
Attached is a screenshot and the max file

[maru]

I am not sure if I understand this message correctly, but if you mean that the SSS properties are only taken from the base material when using the Corona Layered Material, then this is currently the expected behavior and it may be changed in the future.
It is currently the same with displacement.

[quizzy]

sure, but thats not the issue. If you would open the max file... a thin box on top of another box 2 different materials, BUT both with SSS. The SSS disapears

[quizzy]

see attachment.

2 boxes stacked on top of each other.

Box A has material X with SSS enabled + Box B has material Y with SSS enabled = No SSS in Box B

Box A has material X with SSS enabled + Box B has material X with SSS enabled = SSS in Box B

[quizzy]

render preview

[pokoy]

I guess that's how it works in Corona, something similar happens when using multisubs on characters where mesh elements get separate materials, the SSS boundaries are defined per material. You could work around this by using one material for both objects with multi maps to control specific parameters of each object based on material ID.

[maru]

I get it now, sorry. This is the result of using the SSS mode, which is a bit more "fake" compared to the Volumetric Scattering mode. When using the Volumetric Scattering mode, the issue does not appear.

[maru]

This is the expected behavior of the simplified SSS mode.