A New Partitioning Method for Architectural Environments

Computing global illumination in a moderate time for complex environments and walking through them is one of the challenges in computer graphics. To meet this goal, a preprocessing is necessary. This preprocessing consists in partitioning the environment into cells and determining visibility between these cells. Most of the existing partitioning methods rely on the Binary Space Partitioning technique (BSP) which can be easily applied to axial environments. But for non axial scenes the BSP has an important complexity of O(n^3) in time to construct a tree of size at worst O(n^2), n beeing the total number of input polygons. Moreover this technique entails a too important number of cells which do not necessarily fit with the topology of the environment. We propose in this paper a model-based partitioning method which can be applied to non axial buildings. It results in a few number of cells fitting at best with the environment topology. The problem of visibilty calculation is not addressed in this paper.