I have created some columns with the standard “Add Column” (or “Add Beam”) component. You can see from the image that the columns are oriented differently even though I have not set any Cross Section Rotations. I did some initial checks and noticed that my lines are not exactly vertical which is the reason for the rotation error.
I know I can fix my issue by simply making the lines exactly vertical but I am interested into how the local coordinates of the beams/columns are determined. How does Revit (or Grasshopper) interpret the orientation of such lines?