Two stages of refinement -- splitting and averaging.
Averaging masks: a) surface mask (n=7), b) 4-point curve
mask, c) 3-point curve mask.
Point-to-surface projection: a) target triangle localization, b) progressive
refinement of the target triangle.
Dam with a spillway: a) control grid, b) graded mesh.
Mechanical part: a) STL control grid, b) final mesh.