[V8i] How can I Compare the direction of two lines.

Hi!

I have two lines to compare direction.( to check two line go same direction or not.)

I made two Ray3D objects from the lines like below.

Dim oRay_Cell       As Ray3d
Dim oRay_Line     As Ray3d

oRay_Cell = Ray3dFromPoint3dStartEnd(oLineFromCell.startPoint, oLineFromCell.EndPoint)
oRay_Line = Ray3dFromPoint3dStartEnd(oLineFromLine.startPoint, oLineFromLine.EndPoint)

But I don't know how to compare the direction.

oRay_Cell.Direction ,,,,, oRay_Line.Direction