Take the spatial derivative for the normals? Runga-kutta methods work wonders for that: https://en.m.wikipedia.org/wiki/Runge–Kutta_methods https://en.m.wikip

Take the spatial derivative for the normals? Runga-kutta methods work wonders for that: https://en.m.wikipedia.org/wiki/Runge–Kutta_methods https://en.m.wikipedia.org/wiki/Runge–Kutta_methods That works well if they are true signed distance.