AutoCad .Net二次开发求两曲线最小距离

测试结果：

主要思路：假设有两条曲线分别是c1和c2，把c1按照1的距离划分我这里用变量jd表示，得到一个曲线集合coll，然后遍历coll，得到coll中每一个曲线的两个端点，再用这两个端点分别求离曲线c2的最短距离，直接使用开发库的GetClosestPointTo方法就可以了，直到遍历完整个coll集合就能得到最短距离和其对应的点。

主要代码得到曲线集合coll：

 public List<Curve> GetCurves(Curve curve ,double jd)

        {

            List<Curve> lstCurves = new List<Curve>();

            double totalLength = curve.GetDistanceAtParameter(curve.EndParam);

            if (totalLength < jd)

            {

                lstCurves.Add(curve);

                return lstCurves;

            }

            double addLength = ;

            Point3dCollection pt3dCol = new Point3dCollection();

            while (addLength < totalLength)

            {

                pt3dCol.Add(curve.GetPointAtDist(addLength));

                addLength += jd;

            }

            if (addLength != totalLength)

                pt3dCol.Add(curve.GetPointAtDist(totalLength));

           DBObjectCollection dbObjColl= curve.GetSplitCurves(pt3dCol);

            foreach (var item in dbObjColl)

            {

                lstCurves.Add((Curve)item);

            }

            dbObjColl.Dispose();

            return lstCurves;

        }

主要代码得到最短距离和最近点：

public Line GetMinLine(Curve curve1,Curve curve2,double jd)

        {

            List<Curve> lstCurves = GetCurves(curve1, jd);

            double minVal = double.MaxValue;

            Point3d ptMin1 = Point3d.Origin;

            Point3d ptMin2 = Point3d.Origin;

            foreach (var c in lstCurves)

            {

                Point3d pt1 = c.StartPoint;

                Point3d pt2 = c.EndPoint;

                var pt11=curve2.GetClosestPointTo(pt1, false);

                var pt22= curve2.GetClosestPointTo(pt2, false);

                var l1 = pt11.DistanceTo(pt1);

                var l2 = pt22.DistanceTo(pt2);

                if (l1 < minVal)

                {

                    minVal = l1;

                    ptMin1 = pt11;

                    ptMin2 = pt1;

                }

                if (l2 < minVal)

                {

                    minVal = l2;

                    ptMin1 = pt22;

                    ptMin2 = pt2;

                }

            }

            ed.WriteMessage("\n最短距离：" + minVal + "\n");

            return new Line(ptMin1,ptMin2);

        }

关于GetClosestPointTo介绍如下：