The mesh is a part of level geometry. Some of it’s materials have bMagnetic variable in PhysMatProperty. I couldn’t find a way to toggle variables of PhysMatProperty that way it only applied to a single actor and a single material on it. So, I simply added an array of structures that remember IDs and states of these magnetic materials. Like, 0 is on and 2 is off. Too bad trace doesn’t works as I expected.
The easiest solution is to separate meshes to smaller parts that include only one magnetic material.