【NX二次开发】直线与平面交点

 

 

两点式直线与平面交点

/**
    * Brief: 直线与平面的交点
    * Overview: 直线（两点式方程）与平面的交点
    * Param:
    *       douLineStart 输入直线起点
    *       douLineEnd   输入直线终点
    *       douPlanePoint  输入面上的点
    *       douPlaneVector 输入面的方向（非单位向量也可以）
    *       douInterPoint  输出直线与面的交点

    * Return:
    0：成功
    1：直线与面平行，无交点
    */
    int getLineInterPlanePoint(double douLineStart[3], double douLineEnd[3], double douPlanePoint[3], double douPlaneVector[3], double douInterPoint[3])
    {
        //直线两点式方程
        //(x-x1)/(x2-x1) = (y-y1)/(y2-y1) = (z-z1)/(z2-z1) = t
        //x=t*(x2-x1)+x1
        //y=t*(y2-y1)+y1
        //z=t*(z2-z1)+z1

        //平面点法式方程
        //A(x-x0)+B(y-y0)+C(z-z0)=0
        //A((t*(x2-x1)+x1)-x0)+B((t*(y2-y1)+y1)-y0)+C(t*(z2-z1)+z1-z0)=0
        //t=(A(x0-x1)+B(y0-y1)+C(z0-z1))  /    (A(x2-x1)+B(y2-y1)+C(z2-z1))
        double A = douPlaneVector[0];
        double B = douPlaneVector[1];
        double C = douPlaneVector[2];
        double x0 = douPlanePoint[0];
        double y0 = douPlanePoint[1];
        double z0 = douPlanePoint[2];
        double x1 = douLineStart[0];
        double y1 = douLineStart[1];
        double z1 = douLineStart[2];
        double x2 = douLineEnd[0];
        double y2 = douLineEnd[1];
        double z2 = douLineEnd[2];
        if ((A*(x2 - x1) + B*(y2 - y1) + C*(z2 - z1))==0)
        {
            return 1;
        }

        double t = (A*(x0 - x1) + B*(y0 - y1) + C*(z0 - z1)) / (A*(x2 - x1) + B*(y2 - y1) + C*(z2 - z1));
        douInterPoint[0] = t*(x2 - x1) + x1;
        douInterPoint[1] = t*(y2 - y1) + y1;
        douInterPoint[2] = t*(z2 - z1) + z1;
        return 0;
    }

点向式直线与平面交点

/**
    * Brief: 直线与平面的交点
    * Overview: 直线（点向式方程）与平面的交点，方向反了也是可以的
    * Param:
    *       douLineStart 输入直线起点
    *       douLineVec   输入直线方向
    *       douPlanePoint  输入面上的点
    *       douPlaneVector 输入面的方向
    *       douInterPoint  输出直线与面的交点

    * Return:
    0：成功
    1：直线与面平行，无交点
    */
    int getLineInterPlanePoint2(double douLineStart[3], double douLineVec[3], double douPlanePoint[3], double douPlaneVector[3], double douInterPoint[3])
    {
        double douLineEnd[3] = { 0.0,0.0,0.0 };
        douLineEnd[0] = douLineStart[0] + douLineVec[0];
        douLineEnd[1] = douLineStart[1] + douLineVec[1];
        douLineEnd[2] = douLineStart[2] + douLineVec[2];

        //直线两点式方程
        //(x-x1)/(x2-x1) = (y-y1)/(y2-y1) = (z-z1)/(z2-z1) = t
        //x=t*(x2-x1)+x1
        //y=t*(y2-y1)+y1
        //z=t*(z2-z1)+z1

        //平面点法式方程
        //A(x-x0)+B(y-y0)+C(z-z0)=0
        //A((t*(x2-x1)+x1)-x0)+B((t*(y2-y1)+y1)-y0)+C(t*(z2-z1)+z1-z0)=0
        //t=(A(x0-x1)+B(y0-y1)+C(z0-z1))  /    (A(x2-x1)+B(y2-y1)+C(z2-z1))
        double A = douPlaneVector[0];
        double B = douPlaneVector[1];
        double C = douPlaneVector[2];
        double x0 = douPlanePoint[0];
        double y0 = douPlanePoint[1];
        double z0 = douPlanePoint[2];
        double x1 = douLineStart[0];
        double y1 = douLineStart[1];
        double z1 = douLineStart[2];
        double x2 = douLineEnd[0];
        double y2 = douLineEnd[1];
        double z2 = douLineEnd[2];
        if ((A*(x2 - x1) + B*(y2 - y1) + C*(z2 - z1)) == 0)
        {
            return 1;
        }

        double t = (A*(x0 - x1) + B*(y0 - y1) + C*(z0 - z1)) / (A*(x2 - x1) + B*(y2 - y1) + C*(z2 - z1));
        douInterPoint[0] = t*(x2 - x1) + x1;
        douInterPoint[1] = t*(y2 - y1) + y1;
        douInterPoint[2] = t*(z2 - z1) + z1;
        return 0;
    }