Mind map of the meshing process.

The unfitted mesh is obtained after the first labeling stage, while the boundary-fitting process includes additional processing stages for refinement, re-labeling, smoothing, inflation, and optimization via Delaunay turns. A graphics processing unit (GPU) can be applied to accelerate the solid angle labeling and re-labeling stages as well as the surface extraction stage which finds the compartment boundaries after labeling. The re-labeling process is run recursively as long as one or more compartment labels change their value. A pseudocode of this mind map is provided in data in S1 Appendix.