Fast contact force computation for nonpenetrating rigid bodies. We demonstrate the success of our method with real LEGO sculptures built up from a wide variety of 3D models, and compare against previous methods. Building atop our stability analysis, we present a layout refinement algorithm that iteratively improves the structure around the weak portion, allowing for automatic generation of a LEGO brick layout from a given 3D model, accounting for color information, required workload (in terms of the number of bricks) and physical stability. In addition, our stability analysis tells us the weak portion of the sculpture. Unlike previous techniques for Legolization, which typically use heuristic-based metrics for stability estimation, our force-based metric gives 1) an ordering in the strength so that we know which structure is more stable, and 2) a threshold for stability so that we know which one is stable enough. We devise a force-based analysis for estimating physical stability of a given sculpture. In particular, finding a good layout of LEGO bricks that prevents the sculpture from collapsing (due to its own weight) is usually challenging, and it becomes increasingly difficult as the target object becomes larger or more complex.

Building LEGO sculptures requires accounting for the target object's shape, colors, and stability.

Lego virtual building tool