Disclosed are methods, systems, and articles of manufactures for implementing physical designs by using multiple force models to iteratively morph a layout decomposition. In addition to attractive force model(s) or repulsive force model(s), the physical implementation also uses a containment force model for grouping multiple design blocks or for confining a node of a cell within the boundary of a container. Another aspect is directed at deriving a first force model at the first hierarchical level from a second force model at the second hierarchical level by directly modifying the second model based at least in part on characteristic(s) of the first hierarchical level and of the second hierarchical level. In a design with multiple hierarchies, a cell-based force model is also used to ensure child nodes of a parent cell stay within a close proximity of the parent node of the parent cell.