//计算两点之间的中点AcGePoint3d MidPoint(AcGePoint3d pt1, AcGePoint3d pt2){ AcGePoint3d pt; pt.x = (pt1.x + pt2.x)/2; pt.y = (pt1.y + pt2.y)/2; pt.z = (pt1.z + pt2.z)/2; return pt;}