When I convert a spline to a vector, the result is a vector in the Z direction. I know that splines cannot be converted to a spline like this, but the result is odd to me regardless. Why doesn’t this result in a or a vector between the end points?
3. Attach minimal versions of all the relevant files
Convert curve to vector.gh (5.5 KB)
Here the curve must be converted to plane and plane to vector that gives the Normal (Z) of the plane.
If it is a line => Frame=> line direction
And if not planar => error
So be careful with auto-conversion. For example a color is transformed to a point3d with values in X, Y and Z ranging from [-1 to 1] but color with values as RGB require values [0 1].
what @laurent_delrieu said, plus the thing that depending if a -planar- curve is clockwise or counterclockwise, you will get the opposite plane 