In this web content, the author discusses the importance of island management in physics engines and its impact on solver design and performance. They compare three approaches for island management: depth-first search (DFS), parallel union-find, and persistent islands. The author explains that islands are connected components in a rigid body simulation and are an optimization for performance. They also discuss the concept of sleeping and waking bodies in islands, the benefits of parallel island simulation for multicore processors, and the challenges faced when implementing parallel union-find. The author introduces the idea of persistent islands, which are retained across time steps and allow for incremental addition and removal of bodies and constraints. Overall, the content provides insights into the technical aspects of island management in physics engines and offers considerations for optimization and performance.
https://box2d.org/posts/2023/10/simulation-islands/