GMSGroundOverlay animating - should I be using a CATiledLayer?

I got this answer from pressinganswer.com, i think it may helps you.

As currently I cannot use the "position" keypath for animating, I ended up animating it using the "latitude" and "longitude" keypaths separately.

First calculate the points and add them to 2 separate arrays, one for latitude value (y) and one for longitude (x) and then use the values property in CAKeyFrameAnimation to animate. Create 2 CAKeyFrameAnimation objects (1 for each axis) and group them together using CAAnimationGroup and animate them together to form a circle.

In my equation I vary the length of the radius on each axis so that I can also generate an oval path.

NSMutableArray *latitudes = [NSMutableArray arrayWithCapacity:21];    NSMutableArray *longitudes = [NSMutableArray arrayWithCapacity:21];    for (int i = 0; i <= 20; i++) {        CGFloat radians = (float)i * ((2.0f * M_PI) / 20.0f);        // Calculate the x,y coordinate using the angle        CGFloat x = hDist * cosf(radians);        CGFloat y = vDist * sinf(radians);        // Calculate the real lat and lon using the        // current lat and lon as center points.        y = marker.position.latitude + y;        x = marker.position.longitude + x;        [longitudes addObject:[NSNumber numberWithFloat:x]];        [latitudes addObject:[NSNumber numberWithFloat:y]];    }    CAKeyframeAnimation *horizontalAnimation = [CAKeyframeAnimation animationWithKeyPath:@"longitude"];    horizontalAnimation.values = longitudes;    horizontalAnimation.duration = duration;    CAKeyframeAnimation *verticleAnimation = [CAKeyframeAnimation animationWithKeyPath:@"latitude"];    verticleAnimation.values = latitudes;    verticleAnimation.duration = duration;    CAAnimationGroup *group = [[CAAnimationGroup alloc] init];    group.animations = @[horizontalAnimation, verticleAnimation];    group.duration = duration;    group.repeatCount = HUGE_VALF;    [marker.layer addAnimation:group forKey:[NSString stringWithFormat:@"circular-%@",marker.description]];