Adding a particle emitter to the FlappySwift project

Question

I've been having a play with Swift today, I forked the FlappyBird clone and have been making a few changes, like adding collision detection.

I'd like to have some particles emitted when the bird hits the pipe, so I've done a bit of reading and found the SKEmitterNode class. However all the documentation is in Objective-C so I'm having to transpose it all to Swift as there's currently nothing online about how to use SpriteKit in Swift.

This is how I'm attempting to create the Emitter

// sparkles and burstEmitter are defined as class variables
sparkles = SKTexture(imageNamed: "bird-01") //reusing the bird texture for now
burstEmitter = SKEmitterNode()
burstEmitter.particleTexture = sparkles
burstEmitter.position = CGPointMake(200, 200)
burstEmitter.particleBirthRate = 20
burstEmitter.numParticlesToEmit = 200;
self.addChild(burstEmitter)

Does this look right?

When I build I don't see any particles on screen.

The full source of my fork is on github here - https://github.com/jolyonruss/FlappySwift

Thanks for any help

score 2 · Accepted Answer · answered Jul 05 '14 at 04:38

2

You can also make use of Xcode 6's own particle editor via .sks files.

Here's some code I got working in Swift with the added benifit of being able to edit the particle effect in XCode

//spark particle effect

    let sparkEmmitterPath:NSString = NSBundle.mainBundle().pathForResource("sparkParticleEffect", ofType: "sks")

    let sparkEmmiter = NSKeyedUnarchiver.unarchiveObjectWithFile(sparkEmmitterPath) as SKEmitterNode

    sparkEmmiter.position = CGPointMake(self.frame.size.width/2, self.frame.size.height/2 - 200)
    sparkEmmiter.name = "sparkEmmitter"
    sparkEmmiter.zPosition = 1
    sparkEmmiter.targetNode = self

    self.addChild(sparkEmmiter)

This just places the effect at the center of the screen. Obviously this can be edited based on how you'd use the effects. Hope this helps.

answered Jul 05 '14 at 04:38

Chuck Gaffney

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1

Thanks for the update @Chuck, as an Objective-C novice that actually makes sense, one of the advantages of it's verbosity, I guess. – jolyonruss Jul 07 '14 at 13:39
No problem at all :-) Yeah, I'm liking the ability to edit the particles in Xcode directly with 6. In the past I used a program called PhysicsEditor to sort of do the same thing. Saves time from having to input all of those properties individual in the code. – Chuck Gaffney Jul 07 '14 at 21:18
Just off the top of my head self.removeChild(sparkEmmitter) should remove the effect in this case. Granted, you'd have to re-add it to have it back on. I believe there's also a way to shut it off without removing it entirely form the scene. Just not sure of it at moment; doing so could save framerate by not having to reallocate the particle effect's data. – Chuck Gaffney Sep 29 '14 at 05:17

score 0 · Answer 2 · answered Jun 06 '14 at 16:52

So it turns out that more properties are required by the SKEmitterNode in order for it to work, I added the following and I have some particles emitting.

burstEmitter.particleLifetime = 3.0
burstEmitter.particleSpeed = 10.0
burstEmitter.xAcceleration = 100
burstEmitter.yAcceleration = 50

Adding a particle emitter to the FlappySwift project

2 Answers2