Function extrude_from_plane 

pub fn extrude_from_plane<S: Scalar>(
    part: &mut Part<S>,
    names: &ExtrudeNames<'_>,
    plane: &CoordinateSystem<S>,
    outer: &Profile<S>,
    holes: &[Profile<S>],
    distance: S,
) -> GeopResult<SolidId>

Extrude a profile drawn on a right-handed plane (u x v along its normal w) by distance along w — backwards for a negative distance. outer winds counter-clockwise and the holes clockwise, as seen in the plane’s own (u, v). The start cap lies on plane.

Translates to extrude’s left-handed contract: a negative distance already gives a left-handed (u, v, distance w); a positive one mirrors the plane’s u and v (and so every curve’s x and y, then reverses the loops to restore their winding — the names travel with their curves and joints).