Animating frame Images with ease effect on iPad

Question

Let me show you example (360 Deg 3D Object Rotator):
Demo: http://activeden.net/item/interactive-renders-360-deg-3d-object-rotator/39718?ref=mixDesign


As you see, there is a camera 3D rotating on mouse event. Actually, it is a collection of images (frames) animating frame by frame depending on mouse event.

I want to implement this animation with objective - c using swipe gesture (or maybe I should use another gesture?). So that I can make rotation by my finger, to the left, to the right (I want animation with smooth ease effect, depending on swipe speed velocity).

Note: I have ready images for each frame.

Sample codes, online tutorials doing this will really help me.

! Should I use some external graphics library, in order to keep performance? I have hundreds of images (PNG), each with size of 300kb

Thank you in advance, I really need your help!

Answer 1

I don't think you should use swipe gesture here. I recommend you LongPressGesture with short minimumPressDuration.

Let me show example code:

longPress = [ [UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPressGesture:)] 
longPress.delegate = self;
longPress.minimumPressDuration = 0.05;
[viewWithImage addGestureRecognizer:longPress];


float startX; 
float displacement = 0;
-(IBAction)handleLongPressGesture:(UILongPressGestureRecognizer *)sender
{   

float nowX;
    if ( sender.state == UIGestureRecognizerStateBegan ) 
    {
        startX = [sender locationInView:viewWithImage].x;
    }
    if ( sender.state == UIGestureRecognizerStateEnded || sender.state == UIGestureRecognizerStateCancelled)
    {
       ... do something at end ... 
    }
nowX = [sender locationInView:mainWidgetView].x;
displacement = nowX - startX; 

  // set right rotation with displacement value
  [self rotateImageWith:displacement];
}

Answer 2

Maybe it will be easier to go with touchesBegan:, touchesMoved:, and touchesEnded: here? This will allow you to react to velocity and direction changes very fast.

Update: example can be found here.