a method for resolving collisions for placement of objects in 3d models , including attributing a first state to each object having a hard spatial volume and a second state to each object having a soft spatial volume , predefining a first set of rules to determine whether multiple objects may occupy the same spatial volume based on the combination of the object states , the first set of rules covering all permutations of said first state and said second state , placing a first object in the 3d model , placing a second object in the 3d model , determining whether the first object has a collision with the second object in the 3d model , and resolving the collision based on said first predefined set of rules . furthermore , there can be predefining a second set of rules that override the first set of rules , and where the resolving of the collision is based on said second set of rules . further , the method includes finding “ soft ” and “ hard ” characters on all objects and defining the characters on all objects .