Runtime linear rotation animation

Hello,

I am writing a 3d model importer and I've run into an issue importing animations which have their interpolation mode set to linear. For movement I am able to just set tangents and tangent weights to 0, and this will effectively create a linear interpolation for that curve, but for rotation it's different.

This is the code i'm using for rotation. I am using the same approach to movement which works fine, but for rotation the tangent values seem to be ignored. I have found some solutions online suggesting AnimationUtility, but it's an editor-only class and I need this for runtime.

Code (CSharp):

1.  
2. AnimationCurve rotX = new AnimationCurve();
3. AnimationCurve rotY = new AnimationCurve();
4. AnimationCurve rotZ = new AnimationCurve();
5. AnimationCurve rotW = new AnimationCurve();
6. for (int i = 0; i < times.Length; i++) {
7.     rotX.AddKey(new Keyframe(times[i], values[i].x, 0, 0, 0, 0));
8.     rotY.AddKey(new Keyframe(times[i], values[i].y, 0, 0, 0, 0));
9.     rotZ.AddKey(new Keyframe(times[i], values[i].z, 0, 0, 0, 0));
10.     rotW.AddKey(new Keyframe(times[i], values[i].w, 0, 0, 0, 0));
11. }
12. result.clip.SetCurve(relativePath, typeof(Transform), "localRotation.x", rotX);
13. result.clip.SetCurve(relativePath, typeof(Transform), "localRotation.y", rotY);
14. result.clip.SetCurve(relativePath, typeof(Transform), "localRotation.z", rotZ);
15. result.clip.SetCurve(relativePath, typeof(Transform), "localRotation.w", rotW);
16.