Animate infinite scrolling of an image in a seamless loop

Question

Currently I have an image of clouds of 2048x435 that scrolls across a Landscaped oriented UIImageView of 1024x435 using CABasicAnimation. The cloud image scrolls as it shou

Answer 1

Rob, you rock brother. I was looking for a way to do the same thing but vertically. After reading your answer above I had no problem adjusting it to suit my needs. For anyone that may end up here on their hunt for a vertical solution this is what I ended up with, modeled after the above:

- (IBAction)animateBackground6
{
    UIImage *backgroundImage = [UIImage imageNamed:@"space.png"];
    UIColor *backgroundPattern = [UIColor colorWithPatternImage:backgroundImage];

    CALayer *background = [CALayer layer];
    background.backgroundColor = backgroundPattern.CGColor;
    background.transform = CATransform3DMakeScale(1, -1, 1);
    background.anchorPoint = CGPointMake(0, 1);

    CGSize viewSize = self.backgroundImageView.bounds.size;
    background.frame = CGRectMake(0, 0, viewSize.width,  backgroundImage.size.height +   viewSize.height);
    [self.backgroundImageView.layer addSublayer:background];

    CGPoint startPoint = CGPointZero;
    CGPoint endPoint = CGPointMake(0, -backgroundImage.size.height);

    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
    animation.fromValue = [NSValue valueWithCGPoint:endPoint];
    animation.toValue = [NSValue valueWithCGPoint:startPoint];
    animation.repeatCount = HUGE_VALF;
    animation.duration = 5.0;
    [background addAnimation:animation forKey:@"position"];
}