There was a need to have additional references and characteristic points when modeling reinforcements in order to accurately define them in concrete elements.
Fillet and Hook references let you define a rebar or rebar set in the appropriate position within a fillet or hook. By snapping to these references you can avoid interferences and collisions with other rebar.
For fillets the references are placed at points of tangency and at the mid-point of the fillet arc.
For hooks the references are placed at the point of tangency with the rebar segment, at the point of tangency with the hook extension and at cardinal points between them.
After modifying properties of rebars or reinforced elements snapping to the references is preserved and adjusted to modified settings.
It helps you define concrete reinforcement more accurately.