# How can I rotate the spheres so their hole follows the curve?

I want the holes in the beads to follow the rope/tube/curve that I have them following, but I can't figure out a way to make them have individual rotations and can't find a tutorial to help me. • If you share your blend file with blend-exchange.com it will be more easy to help you. Apr 11 at 6:45

I don't want to be the know-it-all here again, but this kind of question always leads to Align Euler to Vector in many answers.

But it would be much easier to convert the curve directly into points with Curve to Points, whereby the rotation of each point is directly available and the orientation of the objects to be instantiated always follows the curve exactly.

The advantage of this solution is that the Curve Tilt is also respected and the rotation does not have to be tinkered with several nodes. • ok, but depending of the pearl hole axis. which here need to be Z/-Z. But upvoted, this is interesting to know. Apr 11 at 19:59
• @lemon If the axis does not fit, then this would simply have to be adjusted accordingly with Rotate Euler, or the object itself would have to be rotated accordingly. Apr 11 at 20:05
• yes. again this approach is interesting and should be the good answer. Apr 11 at 20:06
• Though, how to know if some kind of inner/hidden algorithm/feature still be available in the future of gn? Apr 11 at 20:08
• @lemon In terms of the rotation (quaternions) of a point on a curve, there is no hidden algorithm. The rotation is calculated according to the curve tilt, which in turn depends on how the curve itself is aligned. The solution with Align Euler to Vector is basically based on the same values: normals & tangents of the curve points. Apr 11 at 20:15

If you have this setting, where the pearl (the object that will be instantiated) has its hole along the Y axis (the green line): We want to orientate this Y axis along the curve tangent. So you can get the Curve Tangent node as a target vector for Align Euler to Vector and choose the Y axis to be oriented to this tangent. In the same principle, you can also use the X axis (in red), which is on the side of the pearl. To be rotated appropriately, this axis has to be along the curve normal. So you can also choose this setting, where the X axis is this time oriented to normal: The Align Euler to Vector has no Rotation input here, as the default rotation is $$(0, 0, 0)$$.
So the output rotation is just what is needed to go either from tangent or normal to make the pearl follow the curve orientation.