Sematic of BRepOffsetAPI_MakePipe ?


I have a question about the semantic of BRepOffsetAPI_MakePipe. I have a crosssection defined
in 0,0 which is translated along several wires to create profiles. When looking at the results it seems to me that extrusion is started from 0,0,0 using the path given by the wire. Is this right ?

What I want is that the extrusion starts at the startpoint of the wire. Is there something more elegant than finding this startpoint and translating the profile to that position ?

Does BRepOffsetAPI_MakePipe automatically rotate the profile that it is perpendicular to the profile ?

Thanks, Carsten

Rob Bachrach's picture

Yes, this is how it behaves, and often is even the desireable behavior.

No, it does not automatically rotate the profile. Sometimes, it is desireable to sweep a profile that is offset or angled w.r.t. the spine wire.

I don't know of an easier way other than translating/rotating the cross-section to the desired point before making the pipe. Another option is to rotate/translate the wire to the cross section and then transform the resulting pipe to the desired location. This isn't necessarily more elegant, just another option.