Make into Floor converts a selection of polygons into floors by adding the current floor hatch style in Perspective view. The appearance of the floor is determined by the current Perspetives Settings. Typically, this feature is used after you convert a top down view of a floorplan created in CC3 or Dungeon Designer Pro in Perspectives view using Projection.
To make selected entities into a floor
1 On the Perspectives toolbar right-click Rectangular Floor , then click Make Into Floor.
2 Select the entities, which must be polygons.
Find out how to convert a floorplan into Persectives view