I'm trying to make a sidescroller using SKTileMapNode and SKTileMaps, but I'm having trouble with the physics bodies of individual tiles. I create them in a loop as described in this link:
https://forums.developer.apple.com/thread/50043
However my player node passes through the ground. What am I doing wrong?
guard let landBackground = childNode(withName: "ground")
as? SKTileMapNode else {
fatalError("Background node not loaded")
}
self.landBackground = landBackground
self.tileSize = landBackground.tileSize
for x in 0...(landBackground.numberOfColumns-1){
for y in 0...(landBackground.numberOfRows-1){
let tile = landBackground.tileDefinition(atColumn: x, row: y)
if(tile != nil){
let rect = CGRect(x: 0, y: 0, width: tileSize.width, height: tileSize.height)
let tileNode = SKShapeNode(rect: rect)
tileNode.position = self.landBackground.centerOfTile(atColumn: x, row: y)
tileNode.position.x -= (tileSize.width * 0.5)
tileNode.position.y -= (tileSize.height * 0.5)
tileNode.physicsBody = SKPhysicsBody(rectangleOf: tileSize, center: tileNode.position)
tileNode.physicsBody?.isDynamic = false
tileNode.physicsBody?.collisionBitMask = playerCategory|groundCategory
//tileNode.physicsBody?.contactTestBitMask = playerCategory
tileNode.physicsBody?.categoryBitMask = groundCategory
landBackground.addChild(tileNode)
}
}
}
SKPhysicsBody(rectangleOf: tileSize, center: tileNode.position)
This is probably not correct. The documentation for the call says:
The center of the square in the owning node’s coordinate system.
This means you should probably use .zero. The physics body is always assumed to be at the same location as the node it belongs to, unless specifically offset. You should never use scene coordinates for this.
Also make sure you have showsPhysics set to true on your SKView so you can see where they really are.
Related
I'm trying to incorporate GameplayKit into a SpriteKit project.
Specifically, I'm trying to use GameplayKit's seek-and-avoid behavior wherein an "enemy" character chases a moving "player" character while avoiding obstacles.
I have managed to make the enemy seek the player, but the enemy's movement is weird/undesirable: The enemy's speed should adjust so that it comes to a halt at the desired end point, however its speed does not change, which makes it overshoot its target considerably.
Think of a fast-moving train: Once it gets up to speed, it's hard to stop; it wants to just keep on moving. It's the same phenomenon with the enemy character sprite. It moves like a heavy, lumbering object that can't stop quickly enough.
Here's what I'm doing (please assume that properties such as node are defined):
Configure the player character's GameplayKit stuff:
let entity1 = GKEntity()
heroAgent = GKAgent2D()
heroComponent = GKSKNodeComponent(node: node)
heroAgent.delegate = self
node.entity = entity1
heroEntity = entity1
if let comp = heroComponent {
entity1.addComponent(comp)
entity1.addComponent(heroAgent)
}
Configure the enemy character's GameplayKit stuff:
let entity = GKEntity()
let agent = GKAgent2D()
let avoid = GKGoal(toAvoid: obstaclesForThisLevel!, maxPredictionTime: 1000.0)
let pursue = GKGoal(toInterceptAgent: heroAgent, maxPredictionTime: 0.0)
nodeComponent = GKSKNodeComponent(node: node)
agent.maxSpeed = 100.0
agent.maxAcceleration = 50.0
agent.position = vector_float2(x: Float(levelData.enemies[i].x), y: Float(levelData.enemies[i].y))
agent.radius = Float(node.size.width*0.5)
agent.behavior = GKBehavior(goals: [avoid, pursue], andWeights: [100.0, 100.0])
agent.delegate = self
node.entity = entity
enemyAgent = agent
if let comp = nodeComponent {
entity.addComponent(comp)
entity.addComponent(agent)
}
nodeEntity = entity
In the SKScene's update(_:) method, set the player agent's position and call the enemy character's update(deltaTime:) method:
//Coordinate the hero agent's position with the hero's actual position. Without this, the values in agentDidUpdate() are nan.
heroAgent.position = vector_float2(x: Float(mainCharacter?.position.x ?? 0.0), y: Float(mainCharacter?.position.y ?? 0.0))
nodeComponent?.node.entity?.update(deltaTime: currentTime-lastFrameTime)
Set the enemy character's position in agentDidUpdate(_:):
func agentDidUpdate(_ agent: GKAgent) {
if let a = agent as? GKAgent2D {
nodeComponent?.node.position = CGPoint(x: CGFloat(a.position.x), y: CGFloat(a.position.y))
}
}
Question: Why is the enemy character overshooting its designated target point instead of managing its speed correctly, and how do I fix the issue?
Thank you!
I decided to only use GameplayKit for the purpose of generating a path around the obstacles (findPath(from:to:) is very helpful), and to simply move the enemy character along that path via SKAction.follow(_:asOffset:orientToPath:speed:) when I want to send the enemy back to its starting position.
So, to accomplish the "seeking" behavior, I'm just doing the following from inside my SKScene's update(_:) method:
let dx = mainCharacter.position.x - enemy.position.x
let dy = mainCharacter.position.y - enemy.position.y
let angle = atan2(dy, dx)
let vx = cos(angle) * enemySpeed
let vy = sin(angle) * enemySpeed
enemy.physicsBody?.velocity.dx = vx
enemy.physicsBody?.velocity.dy = vy
This seeking behavior does not consider obstacles, so the enemy can get kind of stuck behind an obstacle that's located between the enemy and the player. So, it's not ideal, but I think it's going to work for me because of other factors in my game.
To generate a path that does consider obstacles, for use with SKAction, I'm doing the following:
let graph = GKObstacleGraph(obstacles: obstaclesForThisLevel, bufferRadius: 0.0)
let startingPoint = GKGraphNode2D(point: vector_float2(x: Float(enemy.position.x), y: Float(enemy.position.y)))
let endPoint = GKGraphNode2D(point: vector_float2(x: Float(enemy.enemyOriginalPosition.x), y: Float(enemy.enemyOriginalPosition.y)))
graph.connectUsingObstacles(node: startingPoint)
graph.connectUsingObstacles(node: endPoint)
let path = (graph as GKGraph).findPath(from: startingPoint, to: endPoint)
if path.count >= 2 {
let realPath = GKPath(graphNodes: path, radius: 100.0)
let myPath: UIBezierPath = UIBezierPath()
for j in 1..<realPath.numPoints {
let previousPoint = realPath.float2(at: j-1)
let nextPoint = realPath.float2(at: j)
if j == 1 {
myPath.move(to: CGPoint(x: CGFloat(previousPoint.x), y: CGFloat(previousPoint.y)))
}
myPath.addLine(to: CGPoint(x: CGFloat(nextPoint.x), y: CGFloat(nextPoint.y)))
}
}
And finally:
let followPath = SKAction.follow(myPath.cgPath, asOffset: false, orientToPath: false, speed: enemySpeed)
enemy.run(followPath)
Log: Here
Please excuse me if this is a stupid, horrid question, but I have been stuck on it and can't find answers anywhere. I have a few nodes: leftMaze, rightMaze, and player. I am trying to detect when the player collides with any of the other two nodes.
Keep in mind that the only physics I want to actually apply to the two maze nodes is gravity. Other than that, I just want them to pass through the player. Also, feel free to give me all the constructive criticism on my code as I am very new and want to get better! Thank you all so much!
override func didMove(to view: SKView) {
backgroundColor = SKColor.white
// PLAYER CONFIG //
player.xScale = 0.25
player.yScale = 0.25
player.position = CGPoint(x:0,y:0 - (self.frame.height/4))
player.physicsBody = SKPhysicsBody(circleOfRadius: max(player.size.width / 2,
player.size.height / 2))
player.physicsBody!.affectedByGravity = false
player.physicsBody!.collisionBitMask = 0
// SPAWNING GAME OBJECTS //
addChild(player)
// DEBUG //
print(size.width, " / " ,size.height)
print(CGPoint(x: size.width * 0.5 ,y: size.height * 0.1))
timer = Timer.scheduledTimer(timeInterval: 5, target: self, selector: #selector(createMaze),userInfo:nil, repeats: true)
}
func didBegin(_ contact: SKPhysicsContact) {
if contact.bodyA.node == player && contact.bodyB.node == leftMaze{
print("Left Collision!")
}
}
func createMaze(){
/*-------- Right Maze Init --------*/
// HOW BIG THE RIGHT PART OF THE MAZE IS
let randomNumber = arc4random_uniform(UInt32(self.frame.width * 0.66))
// HOW FAR TO PLACE THE RIGHT PART OF THE MAZE FROM THE RIGHT PART OF THE SCREEN
let distanceRight = self.frame.maxX-CGFloat(randomNumber)
// DEFINITION OF RIGHT MAZE
rightMaze.path = UIBezierPath(roundedRect: CGRect(x: 0, y: 0, width: Int(randomNumber), height: mazeHeight), cornerRadius: 0).cgPath
rightMaze.position = CGPoint(x: CGFloat(distanceRight), y: frame.maxY)
rightMaze.fillColor = UIColor.black
//ADDING A PHYSICS BODY AND GRAVITY
rightMaze.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: Int(randomNumber), height: mazeHeight))
rightMaze.physicsBody!.affectedByGravity = true
rightMaze.physicsBody!.collisionBitMask = 0
/*-------- End of Right Maze Init --------*/
/*-------- Left Maze Init --------*/
// WHERE TO PLACE THE LEFT PART OF THE MAZE
let distanceLeft = self.frame.minX
// DEFINITION OF THE LEFT MAZE
leftMaze.path = UIBezierPath(roundedRect: CGRect(x: 0, y: 0, width: Int(self.frame.width-CGFloat(randomNumber)-(player.size.width+20)), height: mazeHeight), cornerRadius: 0).cgPath
leftMaze.position = CGPoint(x: CGFloat(distanceLeft), y: frame.maxY)
leftMaze.fillColor = UIColor.black
//ADDING A PHYSICS BODY AND GRAVITY
leftMaze.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: Int(self.frame.width-CGFloat(randomNumber)-(player.size.width+20)), height: mazeHeight))
leftMaze.physicsBody!.affectedByGravity = true
leftMaze.physicsBody!.collisionBitMask = 0
/*-------- End of Left Maze Init --------*/
addChild(rightMaze)
addChild(leftMaze)
You have no contactTestBitMask on your sprites, so your didBegin is never called.
I am making a platforming game in Swift with SpriteKit involving a main character that jumps around. However, once the level loads the player immediately falls through the ground. You can see it in action here.
I am using SKTilemapNode to create the ground, and looping through the tiles when a level loads to create an SKPhysicsBody on a child node of the tile map. This is very similar to what is demoed in the "What's new in SpriteKit" video at WWDC 2016:
So, here we've got a little platform that I built. A little guy that can run around. And you can see that I got the parallax scrolling going on in the background. And you'll note that I'm colliding with the tiles here. And I achieve this by leveraging custom user data that we can put on each of our tiles. Here, I'll show you in our tile set. Select one of the variants here.
And you can see that we have some user data over here. And I just have a value called edgeTile which is a Boolean, and I set to 1.
So, in code, I'm going through the tile map in our platform demo here, and I'm looking for all of these edge tiles.
And whenever I find one, I create some physics data to allow the player to collide with it.
My function to create a physics body based off of an SKTilemapNode is as follows:
extension SKTileMapNode {
//In order for this to work, edge tile definitions must have the "edge" property in user data
func createPhysicsBody() -> SKPhysicsBody {
var physicsBodies = [SKPhysicsBody]()
for row in 0 ..< self.numberOfRows {
for column in 0 ..< self.numberOfColumns {
if self.tileDefinition(atColumn: column, row: row)?.userData?["edge"] != nil {
physicsBodies.append(SKPhysicsBody(rectangleOf: self.tileSize, center: self.centerOfTile(atColumn: column, row: row)))
}
}
}
let body = SKPhysicsBody(bodies: physicsBodies)
body.affectedByGravity = false
body.isDynamic = false
body.allowsRotation = false
body.pinned = true
body.restitution = 0
body.collisionBitMask = 0b1111
body.categoryBitMask = 0b1111
body.contactTestBitMask = 0b1000
return body
}
func initializePhysicsBody() {
let node = SKNode()
node.name = "Tilemap"
node.physicsBody = createPhysicsBody()
addChild(node)
}
}
So, in my scene setup all I have to do is call tileMap.initializePhysicsBody() to do everything that I need.
The SKPhysicsBody for my player is as follows:
let rect = CGSize(width: 16 * xScale, height: 24 * yScale)
let physics = SKPhysicsBody(rectangleOf: rect)
physics.isDynamic = true
physics.allowsRotation = false
physics.pinned = false
physics.affectedByGravity = true
physics.friction = 0
physics.restitution = 0
physics.linearDamping = 0
physics.angularDamping = 0
physics.density = 100
physics.categoryBitMask = 0b0001
physics.collisionBitMask = 0b0001
physics.contactTestBitMask = 0b0011
physics.usesPreciseCollisionDetection = true
physicsBody = physics
I'm not sure what the problem is here, but if I set the SKTilemapNode's physics body to be dynamic, it works. This is how I had the game working up until this point, however, this creates a lot of jitter in the ground because it's moving as a result of the player hitting it. So, thanks for reading this far at least, and any suggestions would be appreciated.
EDIT.
I think the ERROR Here is not using UInt 32
body.categoryBitMask: UInt32 = 2
body.collisionBitMask: UInt32 = 1
body.contactTestBitMask: UInt32 = 1
And Player
physics.categoryBitMask: UInt32 = 1
physics.collisionBitMask: UInt32 = 2
physics.contactTestBitMask: UInt32 = 2
This should definitely Work
Also try this way for the tileMapNode (given below) rather than creating the extension. This was given in a apple developer forum by dontangg
self.tileMap = self.childNode(withName: "Tile Map") as? SKTileMapNode
guard let tileMap = self.tileMap else { fatalError("Missing tile map for the level") }
let tileSize = tileMap.tileSize
let halfWidth = CGFloat(tileMap.numberOfColumns) / 2.0 * tileSize.width
let halfHeight = CGFloat(tileMap.numberOfRows) / 2.0 * tileSize.height
for col in 0..<tileMap.numberOfColumns {
for row in 0..<tileMap.numberOfRows {
let tileDefinition = tileMap.tileDefinition(atColumn: col, row: row)
let isEdgeTile = tileDefinition?.userData?["edgeTile"] as? Bool
if (isEdgeTile ?? false) {
let x = CGFloat(col) * tileSize.width - halfWidth
let y = CGFloat(row) * tileSize.height - halfHeight
let rect = CGRect(x: 0, y: 0, width: tileSize.width, height: tileSize.height)
let tileNode = SKShapeNode(rect: rect)
tileNode.position = CGPoint(x: x, y: y)
tileNode.physicsBody = SKPhysicsBody.init(rectangleOf: tileSize, center: CGPoint(x: tileSize.width / 2.0, y: tileSize.height / 2.0))
tileNode.physicsBody?.isDynamic = false
tileNode.physicsBody?.collisionBitMask = playerCollisionMask | wallCollisionMask
tileNode.physicsBody?.categoryBitMask = wallCollisionMask
tileMap.addChild(tileNode)
}
}
}
I've created a subclass for a certain type of node, which is called TargetNode. Here's what that looks like, and how I've defined the PhysicsBody for that subclass.
class TargetNode: SKSpriteNode, CustomNodeEvents {
func didMoveToScene() {
isUserInteractionEnabled = true
physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: self.size.width, height: self.size.height))
physicsBody!.isDynamic = true
physicsBody!.restitution = 1.0
physicsBody!.allowsRotation = true
physicsBody!.affectedByGravity = true
}
}
Then, in the scene, I try and add that to the scene (it's a game).
let name = createTarget()
let targetNode = TargetNode(imageNamed: name)
targetNode.didMoveToScene() // added this after question below
targetNode.name = name
fgNode.addChild(targetNode)
chickenNodes.append(targetNode)
targetNode.physicsBody?.velocity = CGVector(dx: 100, dy: 0)
targetNode.position = generateZoneAndPoint()
However, the node is not responding to gravity, even though I've defined the PhysicsWorld, etc., for the scene:
let playableRect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
self.physicsBody = SKPhysicsBody(edgeLoopFrom: playableRect)
self.physicsWorld.contactDelegate = self
It also isn't responding to any kind of impulse that I apply to it. Why is this the case? What do I need to adjust or change?
EDIT: I also called these nodes previously... the code for that was:
enumerateChildNodes(withName: "*//*, using: { node, _ in
if let customNode = node as? CustomNodeEvents {
customNode.didMoveToScene()
}
})
I currently have two SKSpriteNodes that I have added SKPhysicsBodies to. When they have no SKJoint attached, they collide as expected. As soon as I add the SKPhysicsJoint, they just pass right through each other. Any joint I add functions properly, but the SKPhysicsJointLimit only limits the extent to which the nodes can travel apart from each other, not how close they can get. How can I fix this?
Here is code I am using for the joint:
let joint = SKPhysicsJointLimit.joint(withBodyA: object1.physicsBody!, bodyB: object2.physicsBody!, anchorA: CGPoint(x: object1.position.x + iconController.position.x, y: object1.position.y + iconController.position.y), anchorB: CGPoint(x: object2.position.x + iconController.position.x, y: object2.position.y + iconController.position.y))
joint.maxLength = screen.height * 0.4
physicsWorld.add(joint)
PhysicsBody of both nodes:
self.physicsBody = SKPhysicsBody(circleOfRadius: self.size.width / 2)
self.physicsBody?.allowsRotation = false
self.physicsBody?.friction = 0
self.physicsBody?.mass = 0.1
I have tested it with different values for the above modifications of the SKPhysicsBody and it performs the same.
An SKPhysicsJoint object connects two physics bodies so that they are simulated together by the physics world.
You can use also SKPhysicJointPin:
A pin joint allows the two bodies to independently rotate around the
anchor point as if pinned together.
If your objects work well before the SKPhysicsJoint addition with the physic engine so they fired the didBeginContact as you wish and as you have setted, I think your problem is simply a wrong anchor. Try to add:
let skView = self.view as! SKView
skView.showsPhysics = true
to your scene initialization code: you will see an outline of the physic bodies and maybe you'll see the issue immediatly.
To help you I'll try to make an example of elements configured to collide each other:
enum CollisionTypes: UInt32 {
case Boundaries = 1
case Element = 2
}
class GameScene: SKScene,SKPhysicsContactDelegate {
private var elements = [SKNode]()
override func didMoveToView(view: SKView) {
physicsWorld.gravity = CGVector(dx: 0, dy: 0)
self.physicsWorld.contactDelegate = self
let boundariesFrame = CGRectMake(20, 20, 200, 400)
let boundaries = SKShapeNode.init(rect: boundariesFrame)
boundaries.position = CGPointMake(350,150)
let boundariesBody = SKPhysicsBody.init(edgeLoopFromRect: boundariesFrame)
boundariesBody.dynamic = false
boundariesBody.categoryBitMask = CollisionTypes.Boundaries.rawValue
boundariesBody.contactTestBitMask = CollisionTypes.Element.rawValue
boundaries.physicsBody = boundariesBody
addChild(boundaries)
for index in 0..<5 {
let element = SKShapeNode(circleOfRadius: 10)
let body = SKPhysicsBody(circleOfRadius: 10)
body.linearDamping = 0
// body.mass = 0
body.dynamic = true
body.categoryBitMask = CollisionTypes.Element.rawValue
body.contactTestBitMask = CollisionTypes.Boundaries.rawValue | CollisionTypes.Element.rawValue
body.collisionBitMask = CollisionTypes.Boundaries.rawValue | CollisionTypes.Element.rawValue
element.physicsBody = body
element.position = CGPoint(x: size.width / 2, y: size.height / 2 - 30 * CGFloat(index))
elements.append(element)
addChild(element)
}
}
}
Hope it can help you to find your issue.