Massive Destruction in Real Time

Currently, the most popular approach for fracturing objects in games is to pre-fracture models and replace a mesh by its fractured pieces at run time. This new approach uses pre-defined fracture patterns. A fracture pattern is a decomposition of a large, rectangular block into non-overlapping pieces that can be designed by an artist, created procedurally, or simulated. When an object is to be fractured at run time, the pattern is aligned with the impact location and used as a stencil to decompose the model into pieces. Facture patterns give artists more control over the fracture process than more physically based approaches like finite elements. In general, it is also much faster than a real simulation and, on the other hand, less tedious than pre-fracturing game assets.

This demo shows a scene of a Roman arena with one million vertices and half a million faces destroyed by user-guided meteors. To add to the realism of the scene, dust is simulated using a separate 3D fluid simulation and then generated when the model fractures. It follows a flow field that is influenced by the motion of fractured pieces. The rigid-body simulator, the fluid simulation, and the rendering all run in parallel on two NVIDIA GTX 690 GPUs at a constant rate of over 30 fps up to a high level of destruction of the original arena.

This fracture method is described in more detail in the corresponding SIGGRAPH 2013 Technical Paper: Real-Time Dynamic Fracture With Volumetric Approximate Convex Decompositions.