Reactive Programming, ​
Unity 3D and you​

Quick tutorial for using UniRx

by Sam Megidov​​

What's UniRx​?

  • It's a re-implementation of NET Reactive Extensions (ReactiveX) for Unity3D by Yoshifumi Kawai.

ReactiveX is a combination of the best ideas from the Observer pattern, the Iterator pattern, and functional programming.​

So what’s the use of it?​

  • It makes your life easier !​
  • Makes all properties and actions plug-and-play.​
  • Clean and more manageable code.

Let's see some examples

Update score text every time score changes​​

var score = new ReactiveProperty<Int>(0)​


Now every time score changes,
we update text in the scoreText GameObject. ​

No need to put that code into an update loop !

How about a highscore?

  • That's it !​
  • It compares every value and gets the highest number.​
.Scan(int.MinValue, Mathf.Max)​
.SubscribeToText (highscoreText)

How about something more complicated?

var scoreDelayed = ​score.Throttle(TimeSpan.FromMilliseconds(500))

Accumulates amount of added score with a window of 500ms.

score.Select(x => x - scoreDelayed.Value)

Advantages ?

  • Ultra fast performance !
  • Make sequences, delay them, buffer them, and more !
  • Works on all platforms, full source included.
  • Constantly updated,  2 years of updates and counting.

Limitations ?

  • Still lacks some operators, but most useful ones are already there.

  • Not enough documentation for game development.

  • Takes a bit of time to get used to it.

Thank you

Sam Megidov