I want to extrude a profile along a master curve, so that the profile curve is perpendicular to the master curve. I have tried it with **Railrevolve**, but it is not really good because the profile curve can point only to the gives axis. Is it possible? I have tried **Extrude along** but that does not work either.

What about Sweep-ing?

I have tried it but it seems to not working with closed curves.

Do it the analytic way (assuming that the profile is placed the classic way: PlaneXY):

- For each Curve crv in your crvList.
- For each Curve segment in crv.DuplicateSegments();

3a. If segment is first/last and crv is open get the tangent at start/end

3b. Else get the bisector with the previous/next segment tangent. - Compute the
**trim planes**(tangent/bisector, CrossProduct(tangent/bisector, globalZ). - Compute the Plane for classic PlaneToPlane trans (at a
**start offset**found via trigonometry [use a box on profile and get a double d = box.X.Length + some tol] then offset is d/Math.Tan(tangents angle)). Find the**end offset**as well. - Extend each segment both sides with the start/end offsets as above.
- Do the PlaneToPlane trans (5) and do a sweep on that extended rail.
- Trim the Brep with the trim Planes (4) - READ SDK about what part remains in relation to the plane normal.
- Cap (if you want closed Breps).
- Sample the pieces in some Tree.