Fig. 3
From: Precise parallel volumetric comparison of molecular surfaces and electrostatic isopotentials
a Input operands, shown in red and green solids, with black outlines. b Cubic lattice surrounding operands (gray). c, f Surface cubes for both operands (gray boxes). d, e, g Several steps of floodfill propagation (starting at yellow circle, following yellow arrow). i Corner points of each surface cube (joined gray squares) tested for exterior (yellow) or interior (red) state. j Segments that cross the boundary of the output surfaces (Black lines). k Intersection points (white circles) where the segments intersect the output surface. l lookup table representing three dimensional surface constructions with different edge intersection patterns. m Triangles (black lines) approximating the intersection points (gray). n Final output surface, black lines