In some edges, the orientation of the first vertex is reverse which is like to be in the following example, where vertex -4 appears in the first position, and +11 appears in the second position.
TShape # 2 : EDGE 0101000 04A7430C
Tolerance : 1e-007
same parametrisation of curves
same range on curves
- Curve 3D : 4, range : 0 1000
- PCurve : 5 on surface 1, range : 0 1000
UV Points : 0, 0 0, -1000
I don't know whether there are some differences between the two representations like (-4, +11), and (+11, -4) in the above example.
If there are some differences, then my second problem is how to get the two vertices of an edge in their appearance indices. In the above example, I want to get (-4, +11), not
(+11, -4). I have obtained (+11, -4) by using TopExp::FirstVertex and TopExp::LastVertex. My codes are like this:
FirstV = TopExp::FirstVertex(aEdge1);
LastV = TopExp::LastVertex(aEdge1);