Use of normal meshes in three-dimensional imaging

1. A method of forming a model of a three dimensional object, comprising:

forming a coarsest version of the model;

forming a plurality of curves which do not intersect one another, and which start and finish at vertices defining a base domain;

determining non-normal vertices;

repositioning said non-normal vertices to form a number of normal vertices; and

forming a normal mesh based on the normal vertices.

2. A method as in claim 1 , wherein the normal vertices are each defined in terms of one scalar per vertex.