Re-Calculation of View Factor for Moving Domain

When does the view factor calculations for moving domain needs to be re-calculated?

The view factor calculations for moving domain needs to be re-calculated in the following instances,

1) If the geometry is moving or getting deformed or any boundary condition type is getting changed, every time the view factors need to be re-computed.
2) In case of moving domains/solids, with dynamic mesh motion or sliding mesh motion, the s2s view factors should be computed frequently to account for the change in geometries.
3) However, while using MRF, the view factors needn't be updated as only the reference is moving, and not the actual geometry.