I want a SKSpriteNode to keep moving through the screen and bounce with the edges forever. So I set the physics of the edges:
let borderBody = SKPhysicsBody(edgeLoopFromRect: self.frame)
borderBody.friction = 0
self.physicsBody = borderBody
physicsWorld.gravity = CGVectorMake(0, 0)
And then the physics of the sprite:
ball.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
ball.size = CGSizeMake(30, 30)
ball.physicsBody = SKPhysicsBody(circleOfRadius: ball.size.width/2)
ball.physicsBody?.allowsRotation = false
ball.physicsBody?.restitution = 1.0
ball.physicsBody?.linearDamping = 0.0
ball.physicsBody?.friction = 0.0
ball.physicsBody?.applyImpulse(CGVectorMake(10, -10))
self.addChild(ball)
The problem is that the sprite is not being affected in anyway by the physics and stays on the center of the screen. What did I do wrong?
you need to add the ball to your scene before you apply the impulse to it.
import SpriteKit
class GameScene: SKScene {
override func didMoveToView(view: SKView) {
let borderBody = SKPhysicsBody(edgeLoopFromRect: self.frame)
borderBody.friction = 0
self.physicsBody = borderBody
physicsWorld.gravity = CGVectorMake(0, 0)
let ball = SKSpriteNode(color: SKColor.redColor(), size: CGSizeMake(30, 30))
ball.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
ball.physicsBody = SKPhysicsBody(circleOfRadius: ball.size.width/2)
ball.physicsBody?.allowsRotation = false
ball.physicsBody?.restitution = 1.0
ball.physicsBody?.linearDamping = 0.0
ball.physicsBody?.friction = 0.0
self.addChild(ball)
ball.physicsBody?.applyImpulse(CGVectorMake(10, -10))
}
}
Related
It's my very first post in coding forum - it means i'm REEAAAAALLLY stuck (I've searched everywhere and tested many options).
Creating a simple bouncing ball on my ipad screen, coding the app using SpriteKit.
The below code prevent the ball to move at all BUT when i remove the SKPhysicsBody created out the frame.edge : the ball falls.
I've got the feeling that the self.physicsBody is ultimately made as a volume despite I ask it to be made from an edge...
Can you please help ?
override func didMove(to view: SKView) {
self.physicsWorld.gravity = CGVector(dx: 0,dy: -6)
self.physicsBody = SKPhysicsBody(edgeLoopFrom: self.frame) // ball's cage
self.physicsBody?.friction = 0;
let fbound = SKShapeNode(rect: self.frame)
fbound.lineWidth = 1
fbound.strokeColor = .red
addChild(fbound)
let path = CGMutablePath()
path.addArc(center: CGPoint(x: view.bounds.width / 2, y: view.bounds.height / 2),
radius: 15,
startAngle: 0,
endAngle: CGFloat.pi * 2,
clockwise: true)
let ball = SKShapeNode(path: path)
ball.lineWidth = 1
ball.fillColor = .red
ball.strokeColor = .black
ball.glowWidth = 0.5
ball.physicsBody = SKPhysicsBody(circleOfRadius: ball.frame.size.width/2)
ball.physicsBody?.friction = 0
ball.physicsBody?.restitution = 1
ball.physicsBody?.mass = 0.6
ball.physicsBody?.linearDamping = 0
ball.physicsBody?.allowsRotation = false
ball.physicsBody?.isDynamic = true
addChild(ball)
}
Please let me know if you need more details
Thanks a mil in advance
Rgds
This code is supposed to drop a ball from the top of the screen to the bottom. And once it touches the bottom of the screen, it should appear back to the top of the screen. It doesn't relocate to the top and it stops moving. I want it to be a continuous loop that resets the ball.y position every time it touches the bottom.
import SpriteKit
class GameScene: SKScene {
let ball = SKShapeNode(circleOfRadius: 20)
let label = SKLabelNode(fontNamed: "Futura")
let movingObjects = SKSpriteNode()
override func didMoveToView(view: SKView) {
let sceneBody = SKPhysicsBody(edgeLoopFromRect: self.frame)
self.physicsBody = sceneBody
//Ball Transition
let ballTransition = SKAction.sequence([SKAction.fadeInWithDuration(1)])
ball.runAction(ballTransition)
//Ball function
ball.fillColor = SKColor.redColor()
ball.physicsBody = SKPhysicsBody(circleOfRadius: 25)
ball.physicsBody?.affectedByGravity = false
//Ball Movement
ball.position = CGPoint(x: self.frame.size.width/2, y: CGFloat(self.frame.size.height*1))
ballMovement()
movingObjects.addChild(ball)
self.addChild(label)
}
func ballMovement() {
let moveBall = SKAction.moveToY(self.frame.size.height*0, duration: 3)
let removeBall = SKAction.removeFromParent()
let moveAndRemove = SKAction.sequence([moveBall, removeBall])
ball.runAction(moveAndRemove)
//Label Sprite
label.position = CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))
label.fontColor = SKColor.redColor()
label.fontSize = 30
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
label.text = "\(ball.position.y)"
if ball.position.y < 26 {
ball.position = CGPoint(x: self.frame.size.width/2, y: CGFloat(self.frame.size.height*1))
}
}
}
removing the ball from its parent within the action and still acting on it elsewhere is going to become very fragile as your program gets more complex. Why not just do it all with the actions and let sprite kit worry about it ?
let moveBall = SKAction.moveToY(0, duration: 3)
let goBackUp = SKAction.moveToY(self.frame.size.height, duration:0)
let keepFalling = SKAction.sequence([moveBall, goBackUp])
ball.runAction(SKAction.repeatActionForever(keepFalling))
I am trying to make my 'Enemy' bounce off all the boundaries. For example, when the Enemy collides with the left, right, top and bottom of the screen, it should change direction.
This is my current code:
import SpriteKit
import GameplayKit
struct Physics {
static let Enemy: UInt32 = 0x1 << 1
let BorderCategory : UInt32 = 0x1 << 2
let BottomCategory : UInt32 = 0x1 << 3
let BallCategory : UInt32 = 0x1 << 4
}
class GameScene: SKScene {
var Enemy = SKSpriteNode()
var gameStarted = Bool()
var gameState = "running"
var destX : CGFloat = 0.0
var destY : CGFloat = 0.0
var score = 0
override func didMove(to view: SKView) {
let borderBody = SKPhysicsBody(edgeLoopFrom: self.frame)
borderBody.friction = 0
self.physicsBody = borderBody
let screenSize: CGRect = UIScreen.main().bounds // get the screen size
let screenWidth = screenSize.width //get the width
let screenHeight = screenSize.height //get the height
Enemy = SKSpriteNode(imageNamed: "red2")
Enemy.size = CGSize(width: 60, height: 70)
Enemy.position = (CGPoint(x: self.frame.width / 6 - Enemy.frame.width, y: self.frame.height / 10))
Enemy.physicsBody = SKPhysicsBody(circleOfRadius: Enemy.frame.height / 2)
Enemy.physicsBody?.categoryBitMask = Physics.Enemy
//Enemy.physicsBody?.categoryBitMask = Physics.Ground | Physics.wall
//Enemy.physicsBody?.contactTestBitMask = Physics.Ground | Physics.wall
Enemy.physicsBody?.affectedByGravity = false
Enemy.physicsBody?.isDynamic = true
self.addChild(Enemy)
Enemy.physicsBody?.velocity = CGVector(dx: 50, dy: 50)
if (Enemy.position.x == screenWidth) {
Enemy.physicsBody?.velocity = CGVector(dx: -50, dy: 0) // change direction at edge DOESN'T WORK
}
if(Enemy.position.y == screenHeight){
Enemy.physicsBody?.velocity = CGVector(dx: 0, dy: -50) //change direction at edge DOESN'T WORK
}
}
OK, based on your code I've written a working bouncing sprite. It uses the physics-engine to achieve this, rather than manually changing the direction (which I guess is how you should go about doing this).
override func didMove(to view: SKView) {
let borderBody = SKPhysicsBody(edgeLoopFrom: frame)
borderBody.friction = 0
borderBody.categoryBitMask = Physics.wall
physicsBody = borderBody
let enemy = enemySprite(size: CGSize(width: 60, height: 70), position: CGPoint(x: frame.size.width/2, y: frame.size.height/2))
addChild(enemy)
let force = SKAction.applyForce(CGVector(dx: 300, dy: 300) , duration: 0.1)
enemy.run(force)
}
func enemySprite(size: CGSize, position: CGPoint) -> SKSpriteNode {
let enemy = SKSpriteNode(color: SKColor.red(), size: CGSize(width: 60, height: 80))
enemy.position = CGPoint(x: frame.width/2, y: frame.height/2)
enemy.physicsBody = SKPhysicsBody(circleOfRadius: enemy.frame.height / 2) // A bit silly with circle, but you seem to have an image for this use
enemy.physicsBody?.categoryBitMask = Physics.enemy
enemy.physicsBody?.restitution = 1
enemy.physicsBody?.friction = 0
enemy.physicsBody?.collisionBitMask = Physics.wall
enemy.physicsBody?.affectedByGravity = false
enemy.physicsBody?.angularDamping = 0
enemy.physicsBody?.linearDamping = 0
return enemy
}
A question to consider is also how you set up the scene? Is the scene-size the same as the view-size? Otherwise the scene's physicsBody will not make the ball bounce where you expect it to...
It won't (in most cases) because of your conditions - using equal to operators instead of greater/lower than.
import SpriteKit
class GameScene: SKScene {
override func didMoveToView(view: SKView) {
// Create enemy with physics body attached and add it to the scene
let enemy = SKSpriteNode(color: SKColor.greenColor(), size: CGSize(width: 20, height: 20))
enemy.name = "enemy"
enemy.position = CGPoint(x: size.width / 2, y: size.height / 2)
enemy.physicsBody = SKPhysicsBody(rectangleOfSize: enemy.size)
enemy.physicsBody!.affectedByGravity = false
enemy.physicsBody!.linearDamping = 0
enemy.physicsBody!.mass = 0.1
enemy.physicsBody!.velocity = CGVector(dx: 150, dy: 0)
addChild(enemy)
}
override func didSimulatePhysics() {
let enemy = childNodeWithName("enemy")!
if (enemy.position.x > size.width && enemy.physicsBody!.velocity.dx > 0)
|| (enemy.position.x < 0 && enemy.physicsBody!.velocity.dx < 0) {
enemy.physicsBody!.velocity.dx *= -1
}
}
}
I learn how to create games on iOS. And now I create a Flappy bird clone.
Flappy Bird Clone
And I'm stack on that - when bird touch some pipe it begin rotate. And game of course is over. But when I start a new game Bird still rotates.
If I put this line
bird.physicsBody?.allowsRotation = false
in the GameScene.swift then bird stop rotate at all. That is not what I want. I want to allow rotation. But when start a new game Bird should be in default position and do not rotate.
What should I do to make it work? Thanks for help.
//
// GameScene.swift
// Flappy Bird
//
// Created by Admin on 10.10.15.
// Copyright (c) 2015 Alex. All rights reserved.
//
import SpriteKit
class GameScene: SKScene, SKPhysicsContactDelegate {
var score = 0
var gameOver = false
var gameOverLabel = SKLabelNode()
var scoreLabel = SKLabelNode ()
var bird = SKSpriteNode()
var bg = SKSpriteNode()
var movingObjects = SKSpriteNode()
var labelContainer = SKSpriteNode()
var pipe1 = SKSpriteNode()
var pipe2 = SKSpriteNode()
enum ColliderType: UInt32 {
case Bird = 1
case Object = 2
case Gap = 4
}
func makeBg () {
let bgTexture = SKTexture(imageNamed: "bg.png")
let movebg = SKAction.moveByX(-bgTexture.size().width, y: 0, duration: 10)
let replacebg = SKAction.moveByX(bgTexture.size().width, y: 0, duration: 0)
let movebgForever = SKAction.repeatActionForever(SKAction.sequence([movebg,replacebg]))
for var i: CGFloat = 0; i<2; i++ {
bg = SKSpriteNode(texture: bgTexture)
bg.position = CGPoint(x: bgTexture.size().width / 2 + bgTexture.size().width * i, y: CGRectGetMidY(self.frame))
bg.zPosition = -5
bg.size.height = self.frame.height
bg.runAction(movebgForever)
movingObjects.addChild(bg)
}
}
override func didMoveToView(view: SKView) {
self.physicsWorld.contactDelegate = self
self.addChild(movingObjects)
self.addChild(labelContainer)
makeBg()
scoreLabel.fontName = "Helvetica"
scoreLabel.fontSize = 60
scoreLabel.text = "0"
scoreLabel.position = CGPointMake(CGRectGetMidX(self.frame), self.frame.size.height - 70)
addChild(scoreLabel)
let birdTexture = SKTexture(imageNamed: "flappy1.png")
let birdTexture2 = SKTexture(imageNamed: "flappy2.png")
let animation = SKAction.animateWithTextures([birdTexture,birdTexture2], timePerFrame: 0.1)
let makeBirdFlap = SKAction.repeatActionForever(animation)
bird = SKSpriteNode(texture: birdTexture)
bird.position = CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))
bird.runAction(makeBirdFlap)
bird.physicsBody = SKPhysicsBody(circleOfRadius: birdTexture.size().height/2)
bird.physicsBody!.dynamic = true
bird.physicsBody!.categoryBitMask = ColliderType.Bird.rawValue
bird.physicsBody?.contactTestBitMask = ColliderType.Object.rawValue
bird.physicsBody?.collisionBitMask = ColliderType.Object.rawValue
self.addChild(bird)
var ground = SKNode()
ground.position = CGPointMake(0, 0)
ground.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(self.size.width, 1))
ground.physicsBody!.dynamic = false
ground.physicsBody!.categoryBitMask = ColliderType.Object.rawValue
ground.physicsBody?.contactTestBitMask = ColliderType.Object.rawValue
ground.physicsBody?.collisionBitMask = ColliderType.Object.rawValue
self.addChild(ground)
_ = NSTimer.scheduledTimerWithTimeInterval(3, target: self, selector: Selector("makePipes"), userInfo: nil, repeats: true)
}
func makePipes () {
let gapHeight = bird.size.height * 4
let movementAmount = arc4random() % UInt32(self.frame.size.height / 2)
let pipeOffset = CGFloat(movementAmount) - self.frame.size.height / 4
let movePipes = SKAction.moveByX(-self.frame.size.width * 2, y: 0, duration: NSTimeInterval (self.frame.size.width / 100))
let removePipes = SKAction.removeFromParent()
let moveAndRemovePipes = SKAction.sequence([movePipes,removePipes])
let pipeTexture1 = SKTexture(imageNamed: "pipe1.png")
let pipe1 = SKSpriteNode(texture: pipeTexture1)
pipe1.position = CGPoint(x: CGRectGetMidX(self.frame) + self.frame.size.width, y: CGRectGetMidY(self.frame) + pipeTexture1.size().height/2 + gapHeight/2 + pipeOffset)
pipe1.runAction(moveAndRemovePipes)
pipe1.physicsBody = SKPhysicsBody(rectangleOfSize: pipeTexture1.size())
pipe1.physicsBody?.dynamic = false
pipe1.physicsBody!.categoryBitMask = ColliderType.Object.rawValue
pipe1.physicsBody?.contactTestBitMask = ColliderType.Object.rawValue
pipe1.physicsBody?.collisionBitMask = ColliderType.Object.rawValue
movingObjects.addChild(pipe1)
let pipeTexture2 = SKTexture(imageNamed: "pipe2.png")
let pipe2 = SKSpriteNode(texture: pipeTexture2)
pipe2.position = CGPoint(x: CGRectGetMidX(self.frame) + self.frame.size.width, y: CGRectGetMidY(self.frame) - pipeTexture2.size().height/2 - gapHeight/2 + pipeOffset)
pipe2.runAction(moveAndRemovePipes)
pipe2.physicsBody = SKPhysicsBody(rectangleOfSize: pipeTexture2.size())
pipe2.physicsBody!.dynamic = false
pipe2.physicsBody!.categoryBitMask = ColliderType.Object.rawValue
pipe2.physicsBody!.contactTestBitMask = ColliderType.Object.rawValue
pipe2.physicsBody!.collisionBitMask = ColliderType.Object.rawValue
movingObjects.addChild(pipe2)
var gap = SKNode()
gap.position = CGPoint(x: CGRectGetMidX(self.frame) + self.frame.size.width, y: CGRectGetMidY(self.frame) + pipeOffset)
gap.runAction(moveAndRemovePipes)
gap.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(pipe1.size.width, gapHeight))
gap.physicsBody?.dynamic = false
gap.physicsBody!.categoryBitMask = ColliderType.Gap.rawValue
gap.physicsBody!.contactTestBitMask = ColliderType.Bird.rawValue
gap.physicsBody!.collisionBitMask = ColliderType.Gap.rawValue
movingObjects.addChild(gap)
}
func didBeginContact(contact: SKPhysicsContact) {
if contact.bodyA.categoryBitMask == ColliderType.Gap.rawValue || contact.bodyB.categoryBitMask == ColliderType.Gap.rawValue {
score++
scoreLabel.text = String(score)
} else {
if gameOver == false {
gameOver = true
self.speed = 0
gameOverLabel.fontName = "Helvetica"
gameOverLabel.fontSize = 30
gameOverLabel.text = "Game is over. Tap to play again."
gameOverLabel.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
labelContainer.addChild(gameOverLabel)
}
}
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
if gameOver == false {
bird.physicsBody!.velocity = CGVectorMake(0, 0)
bird.physicsBody!.applyImpulse(CGVectorMake(0, 50))
} else {
score = 0
scoreLabel.text = "0"
bird.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
bird.physicsBody?.velocity = CGVectorMake(0, 0)
bird.physicsBody!.allowsRotation = false
movingObjects.removeAllChildren()
makeBg()
self.speed = 1
gameOver = false
labelContainer.removeAllChildren()
}
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
}
}
An easy solution is to reset the bird's angular speed and rotation angle. Modify the code in touchesBegan which is invoked when game is over:
bird.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
bird.physicsBody?.velocity = CGVectorMake(0, 0)
bird.physicsBody?.angularVelocity = 0
bird.zRotation = 0
I just created a very basic scene in SpriteKit and first problem just appeared.
When two SKShapeNode get in contact, the player node is overlapping the ground node, I can't see why.
Here is my code and a screenshot:
import SpriteKit
class GameScene: SKScene, SKPhysicsContactDelegate {
var contentCreated = false
var player: SKShapeNode?
override func didMoveToView(view: SKView) {
if !contentCreated {
createSceneContents()
contentCreated = true
}
}
func createSceneContents() {
self.backgroundColor = SKColor(white: 1.0, alpha: 1.0)
self.physicsBody = SKPhysicsBody(edgeLoopFromRect: self.frame)
self.physicsWorld.gravity = CGVectorMake(0, -10)
self.physicsWorld.contactDelegate = self
let groundCategory: UInt32 = 0x1 << 0
let playerCategory: UInt32 = 0x1 << 0
let ground = SKShapeNode(rect: CGRectMake(0, 0, self.frame.width, 50))
ground.fillColor = UIColor.blueColor()
ground.lineWidth = 0
ground.position = CGPoint(x: 0, y: 0)
ground.physicsBody = SKPhysicsBody(rectangleOfSize: ground.frame.size)
ground.physicsBody?.dynamic = false
ground.physicsBody?.categoryBitMask = groundCategory
ground.physicsBody?.collisionBitMask = groundCategory
ground.physicsBody?.contactTestBitMask = groundCategory
self.addChild(ground)
player = SKShapeNode(rect: CGRectMake(0, 0, 30, 30))
player?.fillColor = UIColor.blackColor()
player?.lineWidth = 0
player?.position = CGPoint(x: 20, y: 400)
player?.physicsBody = SKPhysicsBody(rectangleOfSize: player!.frame.size)
player?.physicsBody?.mass = 1.0
player?.physicsBody?.categoryBitMask = playerCategory
player?.physicsBody?.collisionBitMask = playerCategory
player?.physicsBody?.contactTestBitMask = playerCategory
self.addChild(player!)
}
}
Thanks.
You might want to have a different bitmask for your ground and player :
let groundCategory: UInt32 = 0x1
let playerCategory: UInt32 = 0x1 << 1
Then you might also want to set the collision / contact bitmask differently :
ground.physicsBody?.categoryBitMask = groundCategory
ground.physicsBody?.collisionBitMask = playerCategory
ground.physicsBody?.contactTestBitMask = playerCategory
player?.physicsBody?.categoryBitMask = playerCategory
player?.physicsBody?.collisionBitMask = groundCategory
player?.physicsBody?.contactTestBitMask = groundCategory
Even so, you'll have something like you already have. However if you turn on the showPhysics (as suggested by #Skoua) :
You can see that the physics body is attached to the bottom left anchor point.
Here is how to fix that :
func createSceneContents() {
self.backgroundColor = SKColor(white: 1.0, alpha: 1.0)
self.physicsBody = SKPhysicsBody(edgeLoopFromRect: self.frame)
self.physicsWorld.gravity = CGVectorMake(0, -10)
self.physicsWorld.contactDelegate = self
let groundCategory: UInt32 = 0x1
let playerCategory: UInt32 = 0x1 << 1
let ground = SKShapeNode(rectOfSize: CGSize(width: self.frame.width, height: 50)) // HERE
ground.fillColor = UIColor.blueColor()
ground.lineWidth = 0
ground.position = CGPoint(x: ground.frame.size.width/2, y: ground.frame.size.height/2) // HERE
ground.physicsBody = SKPhysicsBody(rectangleOfSize: ground.frame.size)
ground.physicsBody?.dynamic = false
ground.physicsBody?.categoryBitMask = groundCategory
ground.physicsBody?.collisionBitMask = playerCategory
ground.physicsBody?.contactTestBitMask = playerCategory
self.addChild(ground)
player = SKShapeNode(rectOfSize: CGSize(width: 30, height: 30)) // HERE
player?.fillColor = UIColor.blackColor()
player?.lineWidth = 0
player?.position = CGPoint(x: 20, y: 400)
player?.physicsBody = SKPhysicsBody(rectangleOfSize: player!.frame.size)
player?.physicsBody?.mass = 1.0
player?.physicsBody?.categoryBitMask = playerCategory
player?.physicsBody?.collisionBitMask = groundCategory
player?.physicsBody?.contactTestBitMask = groundCategory
self.addChild(player!)
}
Don't forget, when placing your node, that the default anchor point is the bottom left of the scene.