I’m trying to get an arc-like spline that connects two points on the surface of a sphere. The sphere represents a planet and the arc should represent a flight path for transporters.

I know how to handle splines and in/out tangents and was able to calculate the location of both spline points but I can’t get the right rotation of the spline / arc. I know two ways to achieve the correct rotation.

- Use local tangents and calculate the spline actor rotation
- Calculate the world tangents and ignore the spline actor rotation

sadly I’m not able to achieve any of the above solutions. I know the look at rotation from point A to B but that is relative to the world up-vector, which is Z. I guess the up-vector I need is somewhat the normal of the sphere surface.

Does anyone have an idea how this can be accomplished?

**Resolved:**

Calculate the world rotation of the spline with “**Make Rot from XZ**” with the average normal from the start and end location as **Z** and the look at rotations forward vector of both points as **X**