Shaw, Erin2015-02-152015-02-1519971467-8659https://doi.org/10.1111/1467-8659.00127This paper extends the hierarchical radiosity method to environments in which geometry and surface attributes can be changed dynamically. New algorithms are presented for maintaining an appropriately-sized mesh and speeding the construction of the corresponding linear system. Mesh folding, the unrefinement of a mesh, is used to optimize mesh size while maintaining a specified error tolerance. Two new interactions are introduced: shadow links guide local shadow clean up after a change in geometry and ghost links guide global mesh folding after a change in surface attributes. The algorithms stabilize the memory requirements of dynamic scenes. Different types of interactions are analyzed to determine how they are affected by changes in geometry. A dynamic scene-partitioning scheme called a motion volume, used in conjunction with a three-dimensional clipping algorithm, provides a fast way to cull interactions that do not need to be updated. The algorithms are demonstrated on several sample scenes.10.1111/1467-8659.00127107-118