Is it possible to load in facetracker and blink after nth amount of seconds in SPARK AR? - spark-ar-studio

I haven't found an answer to this yet, the docs don't really provide much info as well.
But is it possible to load in blink detection after nth amount of seconds?
For example, after 5 seconds, blink detection loads and and starts sending signals to my script.
Appreciate the help!

You can ignore the blink action for the first 5 seconds. Here's how you'd do it with patches: screenshot of blink detection after 5 seconds
The way it works is, the "runtime" patch and "greater than" patches trigger if the runtime is greater than 5. That is is connected to an "and" patch, along with the blink detection and you're effectively ignoring blinks before 5 seconds have passed.

Yes, using the Time module, you can call scripts on a timer.
const Time = require('Time');
function onTimeout(){
//do stuff after 5 seconds
}
let delay = 5000; //5000 milliseconds = 5 seconds
Time.setTimeout(onTimeout, delay);
Documentation of the Time module can be found here: https://sparkar.facebook.com/ar-studio/learn/developer/reference/classes/TimeModule

Related

How do I wait for a random amount of time before executing the next action in Puppeteer?

I would love to be able to wait for a random amount of time (let's say a number between 5-12 seconds, chosen at random each time) before executing my next action in Puppeteer, in order to make the behaviour seem more authentic/real world user-like.
I'm aware of how to do it in plain Javascript (as detailed in the Mozilla docs here), but can't seem to get it working in Puppeteer using the waitFor call (which I assume is what I'm supposed to use?).
Any help would be greatly appreciated! :)
You can use vanila JS to randomly wait between 5-12 seconds between action.
await page.waitFor((Math.floor(Math.random() * 12) + 5) * 1000)
Where:
5 is the start number
12 is the end number
1000 means it's converting seconds to milliseconds
(PS: However, if you question is about waiting 5-12 seconds randomly before every action, then you should have a class with wrapper, which is a different issue until you update your question.)

Issue with delta time server-side

How can I make server-side game run the same on every machine, because when I use server's delta time it works different on every computer/phone.
Would something called 'fixed timestep' help me ?
Yes fixed timestep can help you. But also simple movement with a delta can help you.
Fixed timestep commonly using with a physics because sometimes physics needs to be update more often (120-200hz)than game's render method.
However you can still use fixed timestep without physic.
You just need to interpolate your game objects with
lerp(oldValue, newValue, accumulator / timestep);
In your case probably small frame rate differences causes unexpected results.
To avoid that you should use movement depends delta.
player.x+=5*60*delta;//I assume your game is 60 fps
Instead of
player.x+=5;
So last delta will be only difference between machines.And its negligible since delta difference between 60 and 58 fps is only ~0.0005 secs

Increase Timer interval

I have a timer that calls the function 'bottleCreate' from 500 to 500 miliseconds. But I want that time to increase during the game (getting faster the creation of the bottles, and the game gets more difficult). But I don't know how to increase that variable inside new Timer. Thanks
interval=500;
var my_timer=new Timer(interval);
my_timer.addEventListener(TimerEvent.TIMER, bottleCreate);
my_timer.start();
You want the game to get faster, so the variable needs to decrease, because less time between function calls will make it faster.
According to the Documentation of the Timer Class you can use the delay variable to change the interval speed.
So, to make it faster, you could simply write
my_timer.delay -= 50;
Each time you do this, the function call will be called 50 ms faster.
Be aware though, going beneath 20ms will cause problems, according to the Documentation.
Furthermore, each time you manipulate the delay variable, the timer will restart completely, with the same repeat count you use at initialization.

Smooth 60fps frame rate independent motion in AS3

I'm having trouble achieving frame rate independent motion in AS3 at 60fps. Every frame I measure the time since the previous frame, add it to an accumulator, and if the accumulator is greater than my target time, which is 16.666ms (60fps), a frame is simulated.
The problem is that the AS3 getTimer() only returns a time in milliseconds.
The delta times I get are often 16ms for the first frame, 16ms for the second, then 18ms for the third, and this pattern repeats. This averages out to 16.666. But in the first frame it is lower than the target time (16 < 16.666), so no frame is simulated. In the second frame the accumulator is higher than the target time, but slightly less than double it, so one frame is simulated. For the third frame 18ms pushes the accumulator over double the target time, so two frames are simulated.
So I'm getting this very jerky motion where no frames are rendered, then one, then two, then none, then one, then two, and this continues.
How would I get around this?
Wow... I thought I was only one who found that out.
Yes, the timer class in AS3 is not accurate. It will only trigger every ~16ms which causes MAJOR issues at times.
If want to see 2048 actions in 1000ms: FlashText Markup Language
(To test this, you'll need a method which takes 1ms to execute - just for even stats)
Notice the difference:
CORRECT: 1000ms | timer=0 == 1000 actions
AS3: 1000ms | timer=0 == 62.5 actions
I was able to write a class that works like this:
CORRECT: 1000ms | timer=0 == 1000 actions
RESHAPE TIMER: 1000ms | timer=0 == 1024 actions
NOTE:
it DOES NOT fire an action every ms
it DOES catch up to actions between the 16ms interval
an ACTION (the way I use it) is a method call, each method call can have its own body
The methodology I used to create this was catch-up... basically the first timer event will fire at 16ms... we know we have a full 16ms worth of code time to fire our own actions before the timer class fires again - thats where you inject sub-actions...
The highest I was able to produce was 2048 actions in 1000ms... more than 2 actions per ms.
Now... back to your problem
There is NO WAY to trigger a 0ms timer event. Based on my solution, if you want to by-pass the first 16ms of lag before the timer fires... you can dispatch an event which will fire within 2ms depending on the current system processes.
Possible Solution
If you take my approach for throwing your own actions within the 16ms, then you can build your own timer class. Use events for times under 16ms, when fired... fire 15 more - lol. Basically, you can create your own deltas between the 16ms.

Coder's block: How to fire timer at intervals, compensating for early/late firing

I'm having a silly-yet-serious case of coder's block. Please help me work through it so my brain stops hurting and refusing to answer my questions.
I want to fire a timer at intervals up to a final time. For example, if t = 0, my goal is 100, and my interval is 20, I want to fire at 0, 20, 40, 60, 80, and 100.
The timer is not precise, and may fire early or late. If it first fires at 22, I want to fire again in 18. If it first fires at 19, I want to fire in 21. All I know when the timer fires is the current time, goal time, and firing interval. What do I do?
Edit: Sorry, I wasn't too specific about what the heck I'm actually asking. I'm trying to figure out what kind of math (probably involving taking the modulus of something) needs to be done to calculate the delay until the next firing. Ideally, I also want the timer to by matched to the end time — so if I start the timer initially at 47, it schedules itself to fire at 60 and not at 67, so the last firing will still be at 100.
If the primitive functionality you have is "schedule X to fire once at time T", then your procedure handling X should know the time T0 at which it was supposed to fire (the time T1 at which it actually fired is not needed) as well as the desired firing interval DT and schedule itself for time T0+DT. If the primitive is "fire D from now", then it should schedule for D = T0+DT-T1 (if that's negative then it needs to schedule itself immediately again but record that the scheduled time and the "was supposed to fire at" time are different so it can keep compensating on following firings).
Somebody already mentioned that .NET's Timer does this for you; so does Python's sched stdlib module; so, I'm sure, do many other languages / frameworks / libraries. But in the end you can build it if needed on top of either of the single-scheduling primitives above (one for an absolute time or one for a relative delta from now) as long as you keep track of desired as well as actual firing times!_)
I would use the system clock to check your interval. For example if you know that your interval is every 20 minutes, fire off the first interval, check what the time was, and adjust the next interval start time.
If your language/platform's underlying timers don't do what you want, then it's usually best to implement timers in terms of "target times", which means the absolute time at which you want the timer to fire next. If you platform asks for an "absolute time", then you give it the target time. If it asks for a "relative time" (or, like sleep, a duration), then it is of course target_time - current_time.
The quick way to calculate each target time in turn is:
When you first set up the timer, calculate the "interval" (which might have to be a floating-point value, assuming that won't cripple performance) and also the "target time" of the first timer fire (again, you might need fractions). Record both, and set your underlying timer mechanism, whatever that is.
When the timer fires, work out the next target time by adding the interval to the previous target time.
The problem with that approach is that you might get some very tiny accumulating errors as you add the interval to the target time (or not so tiny, if you haven't used floats).
So the longer and more accurate way is to store the very first start time, the target finishing time, and the number of firings (n). Then you recalculate the target time for each new firing in turn, which makes sure that you don't get cumulative rounding errors. The formula for that is:
target(k) = start + ((target_end - start) * k) / n
Of if you prefer:
target(k) = (k/n) * end + (1-k/n) * start
Where the firings of the timer are k=1, 2, 3, ... n. I was going to make it 0-based, then realised that was daft ;-)
The last thing you have to wrestle with when implementing timers is the difference between "wall clock" time, and real elapsed time as measured by your hardware clock. Wall clock time can suddenly jump forwards or backwards (either by an hour if your wall clock is affected by daylight savings, or by any amount if the system's clock is adjusted or corrected). Real time always increases (as long as it doesn't wrap). Which you want your timer to respect depends on the intended purpose. If you want to know when your last bus leaves, you want a timer firing daily according to wall clock time, but most commonly you care about real time elapsed. A good timer API has options for these kinds of things.
Build a table listing the desired fire times, say 10:00, 10:20, 10:40, 11:00, and 11:20.
If your timer function takes an absolute time, the rest is trivial. Set it to fire at each of the desired times. If for whatever reason you can only set one timer at a time, okay, set it to fire at the first desired time. When that event happens, set it to fire again at the next time in the table, without regard to what time it is now. Each time through, pick up the next time until you're done.
If your timer function only accepts an interval, no big deal either. Find the difference between the desired time and the current time, and set it to fire at that interval. Like if the first time is 10:00 and it's now 9:23, set it to fire in 10:00 minus 9:23 equal 37 minutes. Then when that happens, set the interval to the next desired time minus the current time. If it really fired at 10:02, then the interval is 10:20 minus 10:02 equals 18 minutes. Etc.
You probably should check for the possibility that the next fire time has already passed. If the process can take longer than the interval you might run past it, and even if not, the system might have been down. If a fire time is missed, you may want to do catch up runs, or just skip it and go to the next desired time, depending on the details of your app.
If you can't keep the entire table -- like it goes on to infinity -- then just keep the next fire time. Each time through the process, add a fixed amount to the next fire time, without regard to when the current process ran. Then calculate the interval based on the current time. Like if you have a desired interval of 20 minutes going on forever starting at 10:00, and it's now 9:23, you set the first interval to 37 minutes. Say that actually happens at 9:59. You set the next fire time to 10:00 plus 20 minutes equals 10:20, i.e. base it on the goal time rather than the actual time. Then calculate the interval to the next fire time based on the current time, i.e. 10:20 minus 9:59 equals 21 minutes. Etc.