I. Principle of the algorithm

1. Algorithm overview

   and the line that intersects two different plane lines perpendicularly is called the common perpendicular line of the two different plane lines, and the line segment formed by the point where the common perpendicular line and the two straight lines intersect is called the common perpendicular line of the two different plane linesline segment.The length of the common perpendicular segment of two different plane lines is called the distance between the two different plane lines.See Baidu Encyclopedia or the code below.The lineToLineSegment() function provided in PCL is used to obtain the shortest 3D line segment between two 3D lines,p>