Sweep along 3D Path - profile rotation


I created sweep along 3d path with 2 methods:

  • model in place ->sweep-> pick path (I already had 3d model lines which I used as a path) ->select rectangular profile

  • sweep created inside dynamo by using the same 3d lines (polyline) and imported as family into the project

the thing is, I achieved slightly different results with both methods - the cross-sections of the solids obtained are not always horizontal - profile is rotating slightly (rectangular cross section is not aligned with global coordinates). Using the first method, the section of the solid rotates differently than using the second method. Could you help me to understand this behaviour? In the dynamo script I use the Coordinate System.By plane node to get the planes perpendicular to the 3d line but I don’t know for example what is the relationship of the resulting local coordinate system (X,Y lying on the plane) to the global coordinates).

Try pulling coordinate systems along the curve at a meaningful interval; from there you can review the direction of each individual axises in the sequence to get a feeling for how the curve’s normal is rotating.