I just have a short question to make sure. I could not find any information about the units used in SOFA. So is it safe to assume that all are SI-units? So meters, seconds, kilogramms and thus newtons, pascal etc? Or are there any parameters with units that are not SI?
yes, by default SOFA use SI-units.
However, as you can set manually all the units (positions, forces, gravity, collision detection/repulsion, etc..) you can apply your own scale as long as you have a coherent system.
Hope it helps.