The points are given in a clockwise direction, such that the area of interest is on the right.
Neighbours consists of the object identifiers of the three adjacent triangles, listed such that the first is opposite pointA, the second is opposite pointB and the third is opposite pointC.
The three sides of the triangle are all assumed to be straight line segments, and thus, they need not be specified explicitly. If one or more neighbours do not exist, this may be indicted by the use of the nil value.