Setting volume interactions

Hello,

I am a bachelor’s student and relatively new to SPIS and simulations in general. I have set up a simulation with a basic shape of a satelite inside a sphere. I have made many simulations in a parametric study which gave the results we expected. Now I want to add volume interactions but despite studying manuals, when i set the global parameters as schown in the pictures, when i finalise run configurations I get a pop up window that tells me in the volume interactors inormation section that the number of detected interactors is 0. In group editor in the computational volume group i set the parameter VolInteracFlag as 1 and provided a background density.



The manuals that I have read havent been very helpful and would very much aprecieted help.

Thank you for any potential replies