public Line ProjectParallelOn(Plane plane, Vector3d viewDirection)
{
if (viewDirection.IsOrthogonalTo(plane.NormalVector))
{
throw new ArgumentException("Projection error: view direction is parallel to projection plane!");
}
if (viewDirection.IsParallelTo(this.vector3d_0))
{
throw new ArgumentException("Projection error: view direction and line are collinear!");
}
Point point = this.point_0.ProjectParallelOn(plane, viewDirection);
Point point2 = (this.point_0 + this.vector3d_0.ToPoint()).ProjectParallelOn(plane, viewDirection);
Line line = new Line(point, point2);
line.DirectionVector = line.DirectionVector.Normalize();
return(line);
}
