What is TREEDEPTH variable?

Users with HUGE drawings may want to consider changing the value of the TREEDEPTH variable. It controls the GstarCAD Tree Spatial Index, which specifies the number of times the tree-structured spatial index may divide into branches. Setting the value to -3020 flattens the Z index giving you more granular nodes in the XY which yields faster object selection. It has no effect on the elevations of your objects.