The partitions themselves are transparent to all ligand motion. Diffusing ligand molecules within each spatial subdivision only have to search for potential intersections with the surface elements that pass through the corresponding subdivision. If a ligand's trajectory carries it through a spatial partition, it is raymarched into the adjacent spatial subdivision and the process continues as necessary. The collision detection and raymarching computation within each spatial subdivision is faster than published methods. Double precision, grid-free.
Surfaces composed of convex planar polygons can be of arbitrary complexity.
Coincident surfaces are allowed. Transparent surface properties take precedence over reflective surface properties, i.e. a transparent element coincident with a reflective element produces transparency in the region of overlap. Identical results are obtained on all machine architectures. Surface may contain multiple types of effector sites. Effector sites are tiled onto surfaces by barycentric subdivision.