本人编的求重心小程序，是基于包围盒的，输入数据，和最小立方体边长，step为包围盒扩展边界的数值可取与小立方体边长一样-I find the center of gravity series of small programs, is based on the bounding box of the input data, and the smallest cube edge length, step to extend the boundary of the bounding box valu