Updates the screen image of an object (entity)
When a 3D (or old-style) polyline vertex or block attribute is modified with entmod, the entire complex entity is not updated on the screen. The entupd function can be used to cause a modified polyline or block to be updated on the screen. This function can be called with the entity name of any part of the polyline or block; it need not be the head entity. While entupd is intended for polylines and blocks with attributes, it can be called for any entity. It always regenerates the entity on the screen, including all subentities.
(setq e1 (entnext)) ; Sets e1 to the polyline's entity name (setq e2 (entnext e1)) ; Sets e2 to its first vertex (setq ed (entget e2)) ; Sets ed to the vertex data (setq ed (subst '(10 1.0 2.0) (assoc 10 ed) ; Changes the vertex's location in ed ed ; to point (1,2) ) ) (entmod ed) ; Moves the vertex in the drawing (entupd e1) ; Regenerates the polyline entity e1