We present a novel algorithm developed for decomposing world-space into arbitrary sided high-order polyhedrons for use as navmeshes or other techniques requiring 3D world spatial decomposition. The Adaptive Space Filling Volumes 3D (ASFV3D) algorithm works by seeding world-space with a series of unit cubes. Each cube is then provided with the opportunity to grow to its maximum extent before encountering an obstruction. ASFV3D implements an automatic subdividing system to convert cubes into higher-order polyhedrons while still maintaining the convex property. This allows for the generation of navigation meshes with high degrees of coverage while still allowing the use of large navigation regions—providing for easier agent navigation in virtual worlds. Compared to the Space-filling Volumes and Automatic Path Node Generation navigation mesh decomposition methods, ASFV3D provides more complete coverage and a less complex navigation mesh.