Patent ID: 8823712

Claim:
A method implemented by data processing apparatus, the method comprising: applying a first spline to a second spline that is closed to create a third spline, wherein the third spline is closed and has the shape of the second spline as modified by the first spline, and wherein applying the first spline to the second spline comprises determining a plurality of different positions wherein each of the positions is calculated based on, at least, a respective curve value of a point on the first spline and a normal of a corresponding respective point on the second spline, wherein the third spline intersects each of the positions; linking corresponding vertices of the third spline and a fourth spline to create a three-dimensional geometry comprising a plurality of first polygons; detecting an opening in the geometry where no vertices of the third spline linked to corresponding vertices on the fourth spline; and in response to the detecting, filling the opening with a plurality of second polygons.