# sweep (extrude) with a twist angle

Hello OCC-Community

I need to extrude a profile (e.g. a simple rectangle in x,y-Area) along a path (e.g. from (0,0,0) to (0,0,100)). Until now this would work fine with BRepOffsetAPI_MakePipe. But now I need additionally to rotate the profile while spweeping with a certain angle. I tried BRepOffsetAPI_MakePipeShell, but found no example how to use it correctly to solve my problem.

Marcel

hi, have you found a solution for the problem? I need to do similiar thing.

Thanks,

Li

I had the same problem, but since my base contour (wire) only consisted of lines (straight edges), and the pipe extrusion direction was also linear, it was easy to create NURBS (BSpline) surfaces that were linear in one direction and a spiral in the other direction. These surfaces are mathematically exact, not approximated. They are called helicoid. You could also handle circular or elliptical arcs in the base contour.

best regards
Gerhard
(since "Notify me about new messages in this thread" doesn't work let me know if you need more information on those surfaces, email "ghofmann at sofa.de")

Hi, Gerhard,

What I want to do it to sweep a cross section which is composed of arc and b-spline curves along a linear path perpendicular to the cross section. The cross section needs to be rotated while it moves along the path (like a helical shape).

It would be highly appreciated if someone has a solution for it.

Thankss,

Li

You might want to take a look at BRepOffsetAPI_MakePipeShell. You would supply the linear trajectory and the 2 end cross sections (defined in the same order, with one rotated). It would apply the twist. If you are twisting more than 90 degrees, you would want to add more intermediate cross sections. In theory, you can also create a better defined twist by using an auxilliary spine, but I've never tried it.

Thank you guys very much for the help. I have made it work using an auxilliary spine. If anyone else facing the same problem, let me know.

Hi, Li

I have the same problem and do not know how to solve, I would really appreciate if you could help me.
Thank you...
Sandy

I have problem about extruding the profile along a path , the wire shape is a I profile I want to extrude it form start point and it must be the center point but it always sweep from edge point .