I have a sprite that the user is able to move side to side by pressing on the left or right side of the screen. If you hold down on either side, the player sprite will leave the screen. I want to stop that from happening using physic bodies, but I can't seem to make it work.
To start, here are my categories.
//Categories for physics bodies
let sceneCategory:UInt32 = 0x1 << 0 // Equal to 1
let playerCategory:UInt32 = 0x1 << 1 // Equal to 2
Here is where I set the physics body of the scene itself.
self.physicsWorld.contactDelegate = self
self.physicsBody = SKPhysicsBody(edgeLoopFrom: self.frame)
self.physicsBody?.categoryBitMask = sceneCategory
self.physicsBody?.contactTestBitMask = playerCategory
self.physicsBody?.collisionBitMask = 0
self.physicsBody?.isDynamic = false
This is how I have the physics set for the player itself. I'm trying to set the physics body around the car itself. Is the way I have it setup the same as setting an alpha mask physics body?
let texture = SKTexture(imageNamed: "PorscheBlue")
player.physicsBody = SKPhysicsBody(texture: texture, size: player.size)
player.physicsBody?.isDynamic = false
player.physicsBody?.categoryBitMask = playerCategory
player.physicsBody?.contactTestBitMask = sceneCategory
player.physicsBody?.collisionBitMask = 0
Then, in the didBegin method, I just wanted it to print showing that the method was called. This isn't happening though for some reason.
func didBegin(_ contact: SKPhysicsContact)
{
print("called")
}
Why isn't the didBegin method being called? Do I have the physics set up properly? How can I make it so the player isn't allowed to leave the screen when moving?
Thank you
EDIT: So when having the physics boundaries visible, it looks like the boundaries for the scene are only being drawn on the top and bottom. I can't see any lines being drawn on the sides. That may be the issue, but I can't get it to show on the sides.
I resolved my issue by changing the dynamic value. I had both set to false, which causes the didBegin function to not be called. At least one of the nodes needs to be dynamic.
Related
I'm trying to create a floating bubble view on my Watch App. The bubbles can collide & bounce off each other & the sides of the screen. But for some reason the bubbles are appearing out of the view bounds & getting stuck on the sides of the frame instead of bouncing off. This code works as expect on my iOS application but when using the same code in my Watch app, it doesn't.
It doesn't make much sense to me that this exact code works perfectly on my iOS app but not on the Watch App.
I'm passing the below code into a SpriteView in my SwiftUI View
let ballCategory: UInt32 = 0xb0001
let edgeCategory: UInt32 = 0xb0010
var nodeCount = 0
override func sceneDidLoad() {
//set physicsWorld properties
physicsWorld.contactDelegate = self
physicsWorld.gravity = CGVector(dx: 0.0, dy: 0.0)
//set edges as PhysicsBody
let edge = SKPhysicsBody(edgeLoopFrom: self.frame)
edge.friction = 0
edge.categoryBitMask = edgeCategory
self.physicsBody = edge
makebubble()
makebubble()
makebubble()
makebubble()
}
func makebubble() {
let bubbleTexture = SKTexture(imageNamed: "bubble")
let bubble = SKSpriteNode(texture: bubbleTexture)
let bphysicsBody = SKPhysicsBody(circleOfRadius: bubbleTexture.size().height/2)
bphysicsBody.isDynamic = true
bphysicsBody.usesPreciseCollisionDetection = true
bphysicsBody.restitution = 0.5
bphysicsBody.friction = 0
bphysicsBody.angularDamping = 0
bphysicsBody.linearDamping = 0
bphysicsBody.categoryBitMask = ballCategory
bphysicsBody.collisionBitMask = ballCategory | edgeCategory
bphysicsBody.contactTestBitMask = ballCategory | edgeCategory
bubble.physicsBody = bphysicsBody
bubble.name = "bubble"
// Get a random possition within the width of the scene
let x = CGFloat(randomize(number: Int(size.width - 40)))
let y = CGFloat(randomize(number: Int(size.height - 40)))
// position the bubble
bubble.position.x = x
bubble.position.y = y
// Add the bubble
addMyChild(node: bubble)
}
func addMyChild(node:SKSpriteNode){
self.addChild(node)
node.physicsBody!.applyImpulse(CGVector(dx: 10.0, dy: -2.0))
nodeCount += 1
}
// function that returns a random int from 0 to n-1
func randomize(number: Int) -> Int{
return Int(arc4random()) % number
}
This has nothing to to with watchOS and everything to do with the small screen size of Apple Watches. Try running your code on iOS with a frame modifier of width 150 and height 150 and you'll see what I mean; the bubbles will likely stick to the side.
Your bubbles look like they stick to the edges because they slow down over time (due to restitution being 0.5 instead of 1) and it's statistically more probable for a bubble to have its final movement close to the screen edge (since they will eventually move to the edge, bounce off from it, thus slowing down and eventually halting).
Here are 3 things you can do about this:
as mentioned, increase restitution to 1 (this is optional, as it won't solve the "sticking to the edge" problem on its own, but it helps making the slowing down issue better)
detect when the bubbles stop (you can do this by checking the x and y velocity in the update(_:) function of your SKScene) and make a force that moves them slightly in a random direction. If you are in a fancy mood, you can even make a timer to make random, barely noticable forces that act like small air movements (chances are, it will even make the animation a bit more realistic)
create an outside bounding box with slightly non-linear/circular borders and corners to make the bubbles bounce off the walls in a different way
I'm trying to develop an IOS game using SpriteKit, and I want to add a Physics body to the scene so that the player won't be able to go through the edges of the screen. At the same time, I want some nodes (for example - bombs that fall from the sky) to be able to go through the edges of the screen.
I know that I can use the following line to add a physics body to the scene:
self.physicsBody = SKPhysicsBody (edgeLoopFrom: self.frame)
My question is how can I allow a "bomb" object to go through such body while having a "player" object obligated to those boundaries.
The answer is relative to categoryBitMask and collisionBitMask of the involved physic bodies.
For example, for the scene:
if let scenePB = scene.physicsBody {
scenePB.categoryBitMask = 1
scenePB.collisionBitMask = 2 // collides with player
}
For the player:
if let playerPB = player.physicsBody {
playerPB.categoryBitMask = 2
playerPB.collisionBitMask = 1+4 // collides with scene and bombs
}
For any bomb:
if let bombPB = bomb.physicsBody {
bombPB.categoryBitMask = 4
bombPB.collisionBitMask = 2 // collides with player
}
I'm currently working on a small iOS game. In its current iteration, 20 targets spawn and move across the screen space-invaders style, and you control a little ship to shoot and destroy them. The code for my targets, the player ship's bullets, and a simple collision detection function I've written in the interim are as follows:
class Red_Target: SKSpriteNode{
var game_scene: GameScene!
private var ship_texture: SKTexture!
convenience init(scale: CGFloat, game_world: GameScene){
self.init(texture: SKTexture(imageNamed: "Proto Target"))
self.ship_texture = SKTexture(imageNamed: "Proto Target")
self.setScale(scale)
game_scene = game_world
game_scene.addChild(self)
self.position = CGPoint(x: game_scene.view!.bounds.width/10, y: 9 * game_scene.view!.bounds.height/10)
//self.physicsBody = SKPhysicsBody(texture: ship_texture, size: self.size)
self.physicsBody = SKPhysicsBody(circleOfRadius: 13)
self.physicsBody!.affectedByGravity = false
self.physicsBody!.collisionBitMask = 0x0
self.physicsBody!.categoryBitMask = CollisionType.Enemy.rawValue
self.physicsBody!.contactTestBitMask = CollisionType.Player_Bullet.rawValue
}
func move() {
self.run(space_invaders(scene: game_scene))
}
}
class PC_Bullet: SKSpriteNode{
convenience init(scale: CGFloat){
self.init(imageNamed: "Goodbullet")
self.setScale(scale)
self.physicsBody = SKPhysicsBody(circleOfRadius: 3)
self.physicsBody!.affectedByGravity = false
self.physicsBody!.categoryBitMask = CollisionType.Player_Bullet.rawValue
self.physicsBody!.collisionBitMask = 0x0
self.physicsBody!.contactTestBitMask = CollisionType.Enemy.rawValue
}
}
func didBegin(_ contact: SKPhysicsContact) {
contact.bodyA.node!.removeFromParent()
contact.bodyB.node!.removeFromParent()
}
}
This code, in its current iteration, works just fine. However, if the line defining the target's physicsbody as its texture is uncommented and the line defining physicsbody as circleOfRadius is removed, the game will consistently crash after the 5th target is destroyed, claiming that didBegin unwraps a nil value. Why does this only happen from physics bodies with textures? Is there any way I could change the code for this to work? I would love to be able to use the physics body from texture function later on, when working with more irregular shapes.
You are pulling a classic nooby mistake. You are removing your bodies too early. If you browse Stackoverflow you will find a plethera of ways to solve it.
The basic idea is do not remove your sprites until the end of the physics phase because your 1 sprite could have multiple contact points to handle. So come up with a way to flag sprites that need to be deleted, and remove them during the didSimulatePhysics function.
I'm trying to add a hitbox to the bottom of my player to only detect platforms. After a lot of trial and error I figured out to have an additional physicsbody attached as a child in a fixed position to another physicsbody I need to use an SKPhysicsJoint. I did this and it seems to have an unforeseen consequence. when I add the hitbox to the player in this way, it alters the players collision / contact bit masks slightly.
In my game you tap the screen to jump and it works seamlessly with no lag like so:
Player jumping
But when I add this hitbox with the joint I have to hold the screen with my finger and eventually the player jumps, but most of the time the input is ignored. Almost as if there's some sort of severe lag when reading the input.In this gif I'm tapping the screen constantly trying to make my player jump and a lot of the inputs are being ignored or blocked:
Player hitbox not behaving
This function setups up the player in my gamescene.swift and adds the hitbox to the player via a fixed SKPhysicsJoint to the scene:
func playerSetup(){
//setups player
addChild(player)
player.addChild(playerPlatformHitbox)
let myCGPoint = player.position // sets joint position
let myJoint = SKPhysicsJointFixed.joint(withBodyA: playerPlatformHitbox.physicsBody!, bodyB: player.physicsBody!, anchor: myCGPoint)
scene?.physicsWorld.add(myJoint)
}
And this is the hitbox class I made to only detect platforms for the player. you'll see it should ignore everything expect platforms from the bit masks. For some reason it's not allowing the player to accept contact with it's bit masks even though this hitbox and player arent touching:
import Foundation
import SpriteKit
class PlayerPlatformHitbox: SKSpriteNode{
init() {
super.init(texture: nil, color: SKColor.blue, size: CGSize(width: playerTexture.size().width, height: 10))
physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: self.size.width, height: self.size.height))
position = CGPoint(x:0, y: (-playerTexture.size().height * 0.6))
physicsBody?.categoryBitMask = CollisionTypes.jumpHitBox.rawValue
physicsBody?.contactTestBitMask = CollisionTypes.platform.rawValue
physicsBody?.collisionBitMask = CollisionTypes.platform.rawValue
physicsBody?.restitution = 0.0
physicsBody?.friction = 0.0
zPosition = 20
physicsBody?.linearDamping = 0.0
physicsBody?.angularDamping = 0.0
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)}
}
And this is my player class
class Player: SKSpriteNode {
init() {
super.init(texture: nil, color: SKColor.clear, size: playerTexture.size())
//starts accelerameter
motionManager = CMMotionManager()
motionManager.startAccelerometerUpdates()
physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: playerTexture.size().width,
height: playerTexture.size().height))
physicsBody?.categoryBitMask = CollisionTypes.player.rawValue
physicsBody?.contactTestBitMask = CollisionTypes.memoryModule.rawValue | CollisionTypes.spikes.rawValue | CollisionTypes.finish.rawValue | CollisionTypes.enemy.rawValue | CollisionTypes.ground.rawValue
physicsBody?.collisionBitMask = CollisionTypes.ground.rawValue | CollisionTypes.sceneEdge.rawValue
physicsBody?.affectedByGravity = true
physicsBody?.restitution = 0.0
physicsBody?.friction = 0.3
physicsBody?.isDynamic = true
//physicsBody?.friction = 0.0
physicsBody?.allowsRotation = false
setScale(0.65)
zPosition = 1
physicsBody?.linearDamping = 0.0
physicsBody?.angularDamping = 0.0
animateWalk()
}
The goal of all this is to use the hitbox to detect platforms instead of the player in this function I have in my update method:
//jump through platform check
if let body = player.physicsBody {
let dy = body.velocity.dy
if dy > 0{
// Prevent collisions if the hero is jumping
body.collisionBitMask &= ~CollisionTypes.platform.rawValue
body.contactTestBitMask &= ~CollisionTypes.platform.rawValue
}
else {
// Allow collisions if the hero is falling
body.collisionBitMask |= CollisionTypes.platform.rawValue
body.contactTestBitMask |= CollisionTypes.platform.rawValue
}
}
and the only reason I need to do this is because when the player is falling, if he falls and hits the side of the platform he will stop and slide down it because collisions are back on and the players physicsbody is a square.
If i can use the platform detection hitbox to detect the platforms instead of the players bulky hitbox it will get rid of this issue.
Thanks for any and all advice.
EDIT: this is the childs behavior with a physics body and no joint:
Odd behavior
I found the solution.
It seems there's some bugs with fixed joints and the answer was to use a "pin" joint instead. This StackO question goes into detail about a rotation bug with fixed joints. On a whim I decided to change my fixed joint to a pin and now the child behaves as you would expect, positionally speaking anyway.
So it appears fixed joints have a few bugs that need to be worked out.
Alright, so my sprite node savior needs to be static so that when it collides with my other node chicken1, it doesn't get flipped upside down or onto its side. It needs to stay right side up.
I set up savior here:
var saviorTexture = SKTexture(imageNamed: "1.png")
saviorTexture.filteringMode = SKTextureFilteringMode.Nearest
savior = SKSpriteNode(texture: saviorTexture)
savior.setScale(0.2)
savior.position = CGPoint(x: self.frame.size.width * 0.5, y: self.frame.size.height * 0.2)
//Savior physics
savior.physicsBody?.allowsRotation = false
savior.physicsBody?.dynamic = false
savior.physicsBody?.affectedByGravity = false
savior.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(savior.size.width, savior.size.height))
savior.physicsBody?.categoryBitMask = ColliderType.Savior.toRaw()
savior.physicsBody?.contactTestBitMask = ColliderType.Chicken1.toRaw()
savior.physicsBody?.collisionBitMask = ColliderType.Chicken1.toRaw()
self.addChild(savior)
As you can see, I have allowsRotation set to false and dynamic set to false, and yet rotation is still being allowed and the node is still dynamic.
Also When I turn on viewing the physics bodies, my 2 other static nodes have green physics bodies while savior has a dark blue physics body, leading me to believe that green is for static and blue is for dynamic. That makes savior definitely dynamic.
What am I doing wrong?
You are setting physics body properties before you are actually declaring one. First declare it like you already do
savior.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(savior.size.width, savior.size.height))
then set all the properties.