Unyielding Objects list
Add objects to this list in that you want to use as deflectors (ground, walls) for Impact, Inactive and Reactor Debris objects.

Unyielding Properties
Simulation Geometry : Geometry for physical interaction during the simulation.
Material : Material presets, use these to quickly assign Friction and Elasticity on next two spinners.
Friction and Elasticity : RayFire will assign these values to Unyielding objects.