§85 impossible-inertia check. Same predicate as warnImpossibleMass: negative or non-finite. Accepts a scalar (2D Z-inertia, or one tensor diagonal) so physics packages can call it without this module importing them.
Optional
§85 impossible-inertia check. Same predicate as warnImpossibleMass: negative or non-finite. Accepts a scalar (2D Z-inertia, or one tensor diagonal) so physics packages can call it without this module importing them.