A cell is typically a group of elements created into a single object. Cells are particularly useful for repetitive objects that occur many times within a design. Traditional cell tools enable cell creation as 2D or 3D objects which are stored in 2D and 3D cell libraries respectively.

Building compound cells provide a 3D model extension to cells. Compound cells combine the ability to create 3D objects with 2D (top view) representations in a single compound cell.