/// <summary>
/// Rotates the element based only on the direction of the placement connector.
/// </summary>
private static void RotateElementInPosition(XYZ placementPoint, Connector conOnFamilyToConnect, Connector startCon, Element element)
{
#region Geometric manipulation
//http://thebuildingcoder.typepad.com/blog/2012/05/create-a-pipe-cap.html
XYZ start = startCon.Origin;
XYZ end = start - startCon.CoordinateSystem.BasisZ * 2;
XYZ dirToAlignTo = (start - end);
XYZ dirToRotate = -conOnFamilyToConnect.CoordinateSystem.BasisZ;
double rotationAngle = dirToAlignTo.AngleTo(dirToRotate);
XYZ normal = dirToAlignTo.CrossProduct(dirToRotate);
//Case: Normal is 0 vector -> directions are already aligned, but may need flipping
if (normal.Equalz(new XYZ(), 1.0e-6))
{
//Subcase: Element needs flipping
if (rotationAngle > 0)
{
Line axis2;
if (dirToRotate.X.Equalz(1, 1.0e-6) || dirToRotate.Y.Equalz(1, 1.0e-6))
{
axis2 = Line.CreateBound(placementPoint, placementPoint + new XYZ(0, 0, 1));
}
else
{
axis2 = Line.CreateBound(placementPoint, placementPoint + new XYZ(1, 0, 0));
}
ElementTransformUtils.RotateElement(element.Document, element.Id, axis2, rotationAngle);
return;
}
//Subcase: Element already in correct alignment
return;
}
Transform trf = Transform.CreateRotationAtPoint(normal, rotationAngle, placementPoint);
XYZ testRotation = trf.OfVector(dirToAlignTo).Normalize();
if (testRotation.DotProduct(dirToAlignTo) < 0.00001)
{
rotationAngle = -rotationAngle;
}
Line axis = Line.CreateBound(placementPoint, placementPoint + normal);
ElementTransformUtils.RotateElement(element.Document, element.Id, axis, rotationAngle);
#endregion
}