What's the effect of setting timeOffset when animating? - iphone

The CAMediaTiming Protocol defines a timeOffset property. Now, they say it's a time offset. It sounds straightforward, but howefer, when I set it to 15.0 for example, the animation still imediately starts. The timeOffset doesn't seem to have any effect.
Maybe someone can point that out a little bit?

The timeOffest property changes the starting point of the animation to a time other than the beginning.
Lets say you have an animation with a duration of 5 seconds. Normally your animation would run from time 0 to time 5. If you set a timeOffset of 2, your animation will start out at time 2, reach time 5 and then 'wrap around' and run time 0 to time 2.
To delay the start of your animation, use the beginTime property.

Related

SwiftUI: Repeat animation forever with delay at the end, without autoreverse

I want to repeat an animation forever, without it to autoreverse, and with a delay/pause between the repetitions after the animation played.
I know there is a .delay() modifier, but it delays the beginning of the animation:
let ani = Animation.easeInOut.delay(1.0).repeatForever(autoreverses: false)
In addition with the .repeatForever modifier, after the animation played it immediately jumps back to its beginning. But I want the last keyframe to remain visible on the screen for a short amount of time.
I’ve also tried it the other way around, adding a .delay() after the .repeatForever modifier, but without success (delay has no effect).
let ani = Animation.easeInOut.repeatForever(autoreverses: false).delay(1.0)
How can I add a delay after the animation played?

Which position value changes when you use an SKAction on an SKSpriteNode? And how would I account for the position changes?

I'm trying to use an SKAction to move my sprites. However, I noticed that after moving the sprites, their position values still remained the same. With some research, I learned that (correct me if I'm wrong) the sprites' position values are actually their location relative to the parent view, and that it was the parent view's position value that had actually changed, and not the sprites'. Only when I checked, the parent view's position value also hadn't changed.
So which position value actually changes?? And how would I go about accounting for the change in position when accessing the sprites' position values? (Since a lot of my game's logic is dependent on their position values)
Here's my code:
let fall = SKAction.moveBy(x: 0, y: -85, duration: 0.2)
print("Original position \(gift.position)")
gift.run(fall)
print("New position \(gift.position)") // Both print the same value
Any help would be greatly appreciated!
Your gift.run(fall) is scheduling an action that will happen over the course of 0.2 seconds, not waiting for it to finish. At 60 frames/second, that means the sprite will reach its final position only after 12 frames. If you print the gift's position at each step in update(_:), you'll see that it is indeed changing.
Since the run does not wait for the action to complete, the sprite hasn't had a chance to move at all when the second print is executed.
If you want something to happen only after an action completes, you have various possibilities. A common way is to add a completion block; see Apple's documentation on getting started with actions: https://developer.apple.com/documentation/spritekit/getting_started_with_actions. Or if you want the same node to do multiple things in order, you can make a composite SKAction, like with the sequence or repeat initializers.

Unity Directional light update (day-night effect)

i'm writing here cause i really need your help. i've created this script linked on a gameObject light (Directional).
var time : int= 0;
function Update () {
time+=1;
transform.Rotate(time*Time.deltaTime, 0 ,0);
yield WaitForSeconds(0.2);
if (time == 360){
time = 0;
}
}
when i start the game, the object don't rotate and if i remove the line:
yield WaitForSeconds(0.2);
the rotation starts slowly then increses its speed until (every 2 rounds) it returns to 0.
Jerdak is right. Update() is called every frame, and not every second. That way, time reaches 360 very fast. In order to get the elapsed time since last call to Update, use Time.deltaTime. Which basically means when you do transform.Rotate(Time.deltaTime * speed, 0, 0);, it'll rotate according to your speed. So use a speed measure rather than a time measure.
the rotation starts slowly then increses its speed until (every 2
rounds) it returns to 0.
This is expected behaviour. Like I said, you used time instead of speed. You increase the speed (named: time) every 0.2 seconds, thus increasing the rotation speed.
when i start the game, the object don't rotate
I am unsure why this happens but when you wait long enough, you'll see the rotation occuring anyway. It might be happening but very slowly.

animate the increasement of a score

SO I have a label labelscore and it increase of 1000 every time there is a collision between two images. I would like to see labelscore increase of 1000 like an animated score, a running score. How can I do this?
You can use an NSTimer to call a routine every 16.7 to 50 milliseconds. In the routine increment some value and update it to the label. Rinse and repeat until this value is equal to the score. This is the basic technique of an animation game loop.
You have the option to use a repeating timer and invalidate it when you're done with it. Or setting single-shot timers within each update routine for the next iteration. You could also use CADisplayLink as an alternative to NSTimer, which may provide smoother animation under some conditions.

small delays/pause in animation

Hi all can anyone help me out with the solution to this problem...
I have a project where I have NSTimer fire about 20 times a sec and thus using only one image(loaded programatically)produces the same image on the iPhone screen about twenty times in a second and these images fall from the top of the screen to the bottom where they are removed(more or less simulating rain fall or rain droplets).
My problem is that looking at the animation, I noticed that there are very small delays and which looks like a break, pause or small vibrations. Thus the flow isn't smooth.
Can anyone help me with the solution please.
Thanks in advance
You can check the CADisplayLink class.
Just because you ask for a timer in the UI run loop to go off at a certain rate, doesn't mean you will get called at exactly that rate or at evenly spaced intervals. You should check the time and the elapsed time "dt" inside each timer callback, and change your animation position, y + dy * dt, etc., accordingly.
Timer's arn't designed to be used for animation.
The best thing to do, is to have a thread running in an infinite loop, where you check if it's time to animate again, or just always animate (giving you a higher frame rate), but using the time elapsed as a reference for the state you are drawing.
You really shouldn't be using a timer for this. Instead you should be using the built in UIView animation methods:
animateWithDuration:animations:
animateWithDuration:animations:completion:
animateWithDuration:delay:options:animations:completion: