SceneKit. How to rotate SCNNode around its axis

Question

I'm trying to achieve same rotation as in scene editor but with code so object always rotate around selected axis, however if I look at angles(x,y,z) in editor they changes quite randomly

![Local node axis][1]

I've tried to use quaternions, but can't get it working

PS. my bad was using rotation property instead of orientation both SCNVector4, have read doc properly)

Answer 1

Seems you was really close, you had to swap parameters in GLKQuaternionMultiply call. I used solution in https://stackoverflow.com/a/39813058/4124265 to achieve rotation only by Z axis:

    let orientation = modelNode.orientation
    var glQuaternion = GLKQuaternionMake(orientation.x, orientation.y, orientation.z, orientation.w)

    // Rotate around Z axis
    let multiplier = GLKQuaternionMakeWithAngleAndAxis(0.5, 0, 0, 1)
    glQuaternion = GLKQuaternionMultiply(glQuaternion, multiplier)

    modelNode.orientation = SCNQuaternion(x: glQuaternion.x, y: glQuaternion.y, z: glQuaternion.z, w: glQuaternion.w)

To rotate arround Y:

    // Rotate around Y axis
    let multiplier = GLKQuaternionMakeWithAngleAndAxis(0.5, 0, 1, 0)
    glQuaternion = GLKQuaternionMultiply(glQuaternion, multiplier)

Answer 2

By setting the rotation property, the absolute rotation of the object is changed, rather than the relative rotation.

Here's some pseudo code

1. Compute the quaternion represents the relative rotation. I would use the GLKQuaternionMakeWithAngleAndAxis function to do so.
2. Apply the rotation to the orientation property:
   let initial_object_orientation = rotateNode.orientation; new_orientation = GLKQuaternionMultiply(rotation_quaternion, initial_object_orientation)
3. Assign the new orientation
   rotatNode.orientation = new_orientation
   Hope it helps.