The approach for live preview has been almost same but we figured out a way to remove the entities that got added in the scene before an entity was finally added in the drawing area. Incorporating another list for entities that were added to the drawing area helped us accomplish this since this was cleared at right moments.
So now live preview is in action for all the entities. The solution was quite simple. Live preview has invigorated the eCAD.
où il ya une volonté , il ya un moyen