Patent ID: 8264487

Claim:
A method for use in computer graphics, comprising: receiving data defining an explicit surface representation of three-dimensional (3D) geometry; defining a narrow band of voxels near the explicit surface; for each voxel in the narrow band, approximating a distance between the voxel and a closest point on the explicit surface by assuming a set of two-dimensional (2D) distances associated with the voxel and a portion of the explicit surface form a triangle; and for each voxel outside of the narrow band, approximating a distance to a closest point on the explicit surface by interpolating the approximated distances in the narrow band; wherein a first of the two-dimensional (2D) distances associated with the voxel comprises a distance between the voxel and a first point on the explicit surface where a ray corresponding to a first scan line intersects both the voxel and the explicit surface; and wherein a second of the two-dimensional (2D) distances associated with the voxel comprises a distance between the voxel and a second point on the explicit surface where a ray intersects the explicit surface, wherein the ray corresponds to a scan line that is different than the first scan line; wherein the first and second two-dimensional (2D) distances form the legs of a right triangle and wherein the hypotenuse of the right triangle approximates a portion of the explicit surface, the distance from the voxel to the hypotenuse approximating the distance from the voxel to the closest point on the explicit surface.