public double DistanceToLine(clsLine3d l2)
{
//Perpendicular distance between 3d lines. Limited to the line segments.
double myNormalDist;
clsPoint3d v1;
clsPoint3d v2;
clsPoint3d M;
double m2;
clsPoint3d R;
clsPoint3d P21;
double t1;
double t2;
clsPoint3d Q1;
clsPoint3d Q2;
//Find the actual point on this line where the perpendicular distance hits. If it is off the line, then find the minimum distance between the end points
v1 = new clsPoint3d(DX(), DY(), DZ());
v1.Normalise();
v2 = new clsPoint3d(l2.DX(), l2.DY(), l2.DZ());
v2.Normalise();
P21 = new clsPoint3d(l2.X1 - X1, l2.X1 - X1, l2.X1 - X1);
M = v2.Cross(v1);
m2 = M.Dot(M);
if (m2 < mdlGeometry.myTol)
{
return(DistanceToPoint(l2.P1));
}
//Parallel
myNormalDist = Abs(P21.Dot(M)) / Sqrt(m2);
//Perpendicular distance
R = P21.Cross(M);
R.Scale(1 / m2);
t1 = R.Dot(v2);
Q1 = P1 + t1 * v1;
if (t1 < 0)
{
Q1 = P1;
}
if (t1 > Length)
{
Q1 = P2;
}
t2 = R.Dot(v1);
Q2 = l2.P1 + t2 * v2;
if (t2 < 0)
{
Q2 = l2.P1;
}
if (t2 > l2.Length)
{
Q2 = l2.P2;
}
return(Q1.Dist(Q2));
}