Many building elements have a symbol that displays in a dynamic view. For example, a door that is cut by a dynamic view cutting plane, has a door swing arc showing the direction by which the door opens. Many times users want to see door swing arcs, even if the door is not cut. This is where the sense distance comes into play.

When the user: (1) sweeps the cutting plane perpendicularly into the forward volume, a distance equal to the Forward Sense Distance; and (2) sweeps the cutting plane perpendicularly into the back volume, a distance equal to the Back Sense Distance; the cutting plane is enlarged into an invisible slab region known as the Sensitive Zone. When a door intersects this zone, a door swing symbol is drawn on the dynamic view, even if the door does not intersect with the cutting plane.

When the Sensitive Distance fields in the View Attributes-Building panel-General tab are zero, the sensitive zone is relegated to the dynamic view cutting plane only. In this case, if a door intersects the cutting plane, it’s swing symbol is drawn on the dynamic view. When the dynamic view sensitive distances are increased by positive values (they cannot be negative), the sensitive zone expands. Now, door swing symbols are drawn for all doors found within the sensitive zone.