1. A method, comprising: loading an object model in a CAD system, the object model including a plurality of shapes; adding the shapes to a cell in a spatial tree in the CAD system, the spatial tree configured to manage a plurality of cells; for each cell that is too complex to process within a memory space of the CAD system, subdividing the cell into a plurality of subcells using a first subdivision process; subdividing each cell into a plurality of subcells using a multi-threaded subdivision process by the CAD system; and combining the subcells into the spatial tree stored in the CAD system.