Open Radar

 
Summary:

In the SceneKit SDK, the SCNNode pivot property is documented as animatable. However, any attempt to animate a change to this property results in the property value not changing at all (and no animation taking place).


Steps to Reproduce:

Create any SCNNode instance. Assign a new value to the pivot property, wrapped in a SCNTransaction. Run the app. Observe no change to the pivot point. Whereas, with the SCNTransaction lines removed (for no animation) the pivot point does change (non-animated).

Example:

    SCNTorus *torus = [SCNTorus torusWithRingRadius:8.0f pipeRadius:3.0f];
    SCNNode *torusNode = [SCNNode nodeWithGeometry:torus];
    [scene.rootNode addChildNode:torusNode];
    
    [SCNTransaction begin];
    [SCNTransaction setAnimationDuration:1.0];
    [SCNTransaction setAnimationTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
    
    torusNode.pivot = CATransform3DMakeTranslation(0.0f, 8.0f, 0.0f);
    
    [SCNTransaction commit];

The same result is observed if an explicit animation is used on the pivot point. For example:

    CABasicAnimation *pivotAnimation = [CABasicAnimation animationWithKeyPath:@"pivot"];
    pivotAnimation.fromValue = [NSValue valueWithCATransform3D:torusNode.pivot];
    pivotAnimation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeTranslation(0.0f, 8.0f, 0.0f)];
    pivotAnimation.duration = 1.0;
    [torusNode addAnimation:pivotAnimation forKey:@"pivot"];


Expected Results:

The pivot property value should change with animation, as the API documentation for SCNNode pivot states that the property is animatable. Quote: "The SCNNode object’s pivot. Animatable."


Actual Results:

The pivot property value does not change and does not animate.


Regression:

n/a


Notes:

n/a