I thank Mihai Popovici and Biondo Biondi for drawing my attention to
the fast marching level set method. Discussions with Bill Symes, Dan
Kosloff, and Tariq Alkhalifah were crucial for developing a general
understanding of the method. Jamie Sethian kindly responded to more
specific questions. The conforming triangulation program was developed
at the suggestion of Leonidas Guibas as a research project for his
Geometrical Algorithms class at Stanford.