How can I add a physics body to an SKAtlasTexture or create an animation through Images.xcassets? - swift

Question

I wanted to create a small animation of a car driving down the road, so I made an atlas of 9 different pictures. The car simply looks like its wheels are rotating and the car is bouncing a bit as it drives along. I already made an SKSpriteNode with an image and added a physics body on it so that it can jump and be affected by gravity.
So I was wondering how to add either a physics body to an SKAtlasTexture or create an animation through my image.xcassets folder. I tried to just change the SKSpriteNode to SKAtlasTexture, but that obviously didn't work as there are no physics bodies in SKAtlasTexture. So that's where I'm at. Any suggestions or solutions would be greatly appreciated.
Here some parts of my code:
class PlayScene: SKScene, SKPhysicsContactDelegate {
let road = SKSpriteNode(imageNamed: "road")
var origRoadPositionX = CGFloat(0)
var maxRoad = CGFloat(0)
var groundSpeed = 3
var carBaseLine = CGFloat(0)
let car = SKSpriteNode(imageNamed: "car")
enum ColliderType:UInt32{
case car = 1
case tower = 2
}
override func didMoveToView(view: SKView) {
self.backgroundColor = UIColor(hex: 0x80E8FF)
self.physicsWorld.contactDelegate = self
//Car
self.car.position = CGPointMake(CGRectGetMinX(self.frame)-20 + self.car.size.width, self.carBaseLine)
self.car.physicsBody = SKPhysicsBody (rectangleOfSize: self.car.size)
self.car.physicsBody?.allowsRotation = false
self.car.physicsBody?.affectedByGravity = false
self.car.physicsBody?.categoryBitMask = ColliderType.car.rawValue
self.car.physicsBody?.contactTestBitMask = ColliderType.tower.rawValue
self.car.physicsBody?.collisionBitMask = ColliderType.tower.rawValue
self.addChild(car)
If more code is needed in order to find a solution, let me know and i can supply more of it.

Answer 1

You can use atlas folder for performing animation with images.
Consider below example:
import SpriteKit
class GameScene: SKScene {
var bombFrames : [SKTexture]!
var bomb : SKSpriteNode!
let NoneCategory : UInt32 = 0x1 << 0
let ProjectileCategory : UInt32 = 0x1 << 2
let bombCategory : UInt32 = 0x1 << 7
override func didMoveToView(view: SKView) {
/* Setup your scene here */
runAction(SKAction.repeatActionForever(SKAction.sequence([SKAction.runBlock(addBomb), SKAction.waitForDuration(5.0)])))
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
}
func addBomb() {
let Name = "Bomb"
let AnimatedAtlas = SKTextureAtlas(named: Name)
var Framese = [SKTexture]()
let numImages = AnimatedAtlas.textureNames.count
for var i=1; i<=numImages; i++ {
let TextureName = "\(i)"
Framese.append(AnimatedAtlas.textureNamed(TextureName))
}
bombFrames = Framese
let firstFrame = bombFrames[0]
bomb = SKSpriteNode(texture: firstFrame)
let actualY = random(min: bomb.size.height/2, max: size.height - bomb.size.height/2)
bomb.position = CGPoint(x: size.width + bomb.size.width/2, y: actualY)
bomb.physicsBody = SKPhysicsBody(texture: bomb.texture, size: bomb.texture!.size())
bomb.physicsBody?.dynamic = true
bomb.physicsBody?.categoryBitMask = bombCategory
bomb.physicsBody?.contactTestBitMask = ProjectileCategory
bomb.physicsBody?.collisionBitMask = NoneCategory
bomb.physicsBody?.usesPreciseCollisionDetection = true
addChild(bomb)
let actualDuration = random(min: CGFloat(2.0), max: CGFloat(4.0))
let actionMove = SKAction.moveTo(CGPoint(x: -bomb.size.width/2, y: actualY), duration: NSTimeInterval(actualDuration))
let actionMoveDone = SKAction.removeFromParent()
bomb.runAction(SKAction.sequence([actionMove, actionMoveDone]))
playBombAnimation()
}
func random() -> CGFloat {
return CGFloat(Float(arc4random()) / 0xFFFFFFFF)
}
func random(#min: CGFloat, max: CGFloat) -> CGFloat {
return random() * (max - min) + min
}
func playBombAnimation() {
bomb.runAction(SKAction.repeatActionForever(SKAction.animateWithTextures(bombFrames, timePerFrame: 0.1, resize: false, restore: true)), withKey:"bombAnimation")
}
}
And don't forget to add atlas folder into your project navigator like this:
As you can see in code you can add physics body to your sprite. and if you want you can try this way.
Hope this will help.