Scattering coefficients - assignment to materials

[DrEStaudinger]

Hi everybody,

I have two questions related to the scattering coefficients:

1. Do you have some good references at hand, where scattering coefficients for specific objects/materials can be directly used?
2. In Sionna, you relate the scattering coefficient to the assigned material, right? However, the scattering coefficient depends on the surface roughness to my understanding. Hence, it should be related to the object in the scene and not necessarily to the material itself. Maybe I missed that, so a hint on that is highly appreciated.

All the best,
Emanuel

[jhoydis]

Hi @DrEStaudinger,

Concerning 2, a material in Sionna does not only capture the roughness but also the thickness of an object. It essentially describes everything that is needed to compute the reflected/refracted/scattered/diffracted field. There is hence no separation between material and object/surface properties.

[DrEStaudinger]

Hi @jhoydis ,

Thank you for the quick reply.
To conclude correctly: I can assign a a single thickness value and single scattering coefficient for one material name only, e.g., dry ground, and assign this material to multiple objects. However, if I want to assign a dry ground like material with different scattering coefficient (but same other properties as dry ground) to another object, I would need to define an entirely new material name to capture this change in the same scene.

[jhoydis]

Exactly.

[DrEStaudinger]

Thanks for the clarification