VMHOLES

vmholes − locates holes in a polygon mesh

vvbody [if=<input_file>] [of=<output_file>] [-v]

vmholes Takes VisionX file containing 3D polygon mesh finds holes where the mesh is not complete. The output is a VisionX file containing 3D vectors that contains information of the holes.

Each 3-D vector will contain the coordinates of the points that form the boundary of the hole. The points are arranged such that they are adjacent to one another on the boundary. The last point is same as the first point. Two adjacent points form the edge of the polygon that surrounded the hole.

To know which direction to fill the hole, information of the normal vectors of the polygons that surround the hole are also computed. They are included immediately after the 3-D vector of the hole information as a 3-D vector containing the unit normal vectors of the corresponding polygon.

Considering two adjacent points on the 3-D vector, let point 1 be the first point on the vector, point 2 to be the second point and point 3 to be the point on the polygon that is not on the vector. The normal is taken in the direction of point 1-2-3 using the right hand rule cross product. If 1-2 is a vector in x-direction and 1-3 in the y-direction, then the normal is in the z-direction. direction of 1st point, 2nd point

vmholes Find the holes when given an input file that contains 3D mesh scan data. The file will contain the bounding box, 3D hole vectors and 3D normal vectors.

vring(1), vbody(1), vholes(1)

Fan Gu, Nov. 2007