1. A method, comprising: loading an object model in a CAD system, wherein the object model includes 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; determining whether each cell is too complex to process within a memory space of the CAD system, and based on the determination, for each cell that is too complex to process within the memory space, subdividing the cell into a plurality of subcells using a first subdivision process, the determination based at least on whether or not each cell and potential subcells of that cell can exist within the memory space based upon shapes currently held within that cell; 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.