I'm trying to make a overlay in my SpriteKit game.
let overlay = SKSpriteNode(color: UIColor.blackColor(), size: self.size)
overlay.alpha = 0.3
self.addChild(overlay)
The Overlay is not been shown on the screen, what is wrong?
You can set the zPosition to a higher value to ensure it is drawn above sprites with a lower zPosition value.
For overlays, an arbitrary high value can be used to ensure it is drawn above all other sprites.
node.zPosition = 100;
You can read more about zPosition here.
Related
I have a SpriteKit game in which balls bounce around, interacting with other objects.
One of those other objects is a spinner that should rotate around its center, but NOT change its x/y position. It should be stationary except for the rotation.
According to Apple's documentation, node.physicsBody.pinned = true should do exactly what I want, making it so that:
"the node’s position is fixed relative to its parent. The node’s position cannot be changed by actions or physics forces. The node can freely rotate around its position in response to collisions or other forces."
However, that's not what's happening. What's happening is that the spinner's y-axis position changes when a ball hits it squarely -- briefly moving down and then popping back into the correct position.
My code for the spinner (please assume all variables are defined):
for i in 0..<spinners.count {
let spinnerNode = SKSpriteNode(texture: texture)
spinnerNode.position = CGPoint(x: spinners[i].minX, y: spinners[i].minY)
spinnerNode.size = CGSize(width: spinners[i].width, height: spinners[i].height)
spinnerNode.physicsBody = SKPhysicsBody(texture: spinnerNode.texture!, size: CGSize(width: spinners[i].width, height: spinners[i].height))
spinnerNode.physicsBody?.isDynamic = true
spinnerNode.physicsBody?.affectedByGravity = false
spinnerNode.physicsBody?.pinned = true
addChild(spinnerNode)
}
Why on earth is my spinner node moving vertically when a ball collides with it? Why isn't .pinned working as advertised?
Thank you for your help!
I solved the problem by setting the spinner node's mass to a value slightly greater than that of the ball nodes.
node.physicsBody?.mass = 6.0
I'm building a menu Game Scene where I have a Logo and 4 buttons, all of those have a SKPhysicsBody with the rectangle size of the image.
All of those I only set:
logo.physicsBody = SKPhysicsBody(rectangleOf: logo.size)
logo.physicsBody?.affectedByGravity = false
Full code of creating the objects (all are the same)
logo = SKSpriteNode(imageNamed: "logo")
logo.anchorPoint = CGPoint.zero
logo.name = "logo"
logo.zPosition = 2
logo.size = CGSize(width: 309, height: 272)
logo.setScale(Generic.utilities.getScale())
self.addChild(logo)
logo.position = CGPoint(x: self.frame.width/2 - logo.size.width/2, y: self.frame.height - logo.size.height - 40)
logo.physicsBody = SKPhysicsBody(rectangleOf: logo.size)
logo.physicsBody?.affectedByGravity = false
and during a button press I change all the nodes affectedByGravity to true so they can fall of the screen and new elements can come in.
The problem I'm having is that when I run the app, the elements are all shifted/tilted on the screen and not in their original position
All I wanted is for them to stay in their position until I click one of the buttons and then they can fall off the screen.
Any reason why when I set a physics body and affectedByGravity they all tilt like this?
Well, Thanks to #RonMyschuk and #Knight0fDragon I found out (didn't know before) that I could add to my Scene loading the following:
skView.showsPhysics = true
Which add border lines around the physicsBody of your nodes, that way you can see them interacting. And by doing that I saw that the physicsBody of one of my nodes was completely in a different position then it should
By taking care of this issue, everything went back to normal
What do I need to code in order to have an image (that is already in the assets.xcassets) displayed as the background of the GameScene.swift?
First of all you could call you scene with the scaleMode .resizeFill that modify the SKScene's actual size to exactly match the SKView :
scene.scaleMode = .resizeFill
.resizeFill – The scene is not scaled. It is simply resized so that its fits the view. Because the scene is not scaled, the images will all remain at their original size and aspect ratio. The content will all remain relative to the scene origin (lower left).
By default, a scene’s origin is placed in the lower-left corner of the view. So, a scene is initialized with a height of 1024 and a width of 768, has the origin (0,0) in the lower-left corner, and the (1024,768) coordinate in the upper-right corner. The frame property holds (0,0)-(1024,768).The default value for the anchor point is CGPointZero (so you don't need to change it), which places it at the lower-left corner.
Finally, you can use the code below to add your background image (called of example bg.jpg):
// Set background
let txt = SKTexture(imageNamed: "bg.jpg")
let backgroundNode = SKSpriteNode(texture: txt, size:size)
self.addChild(backgroundNode)
backgroundNode.position = CGPoint(x: self.frame.midX, y: self.frame.midY)
Although this might not be the best way, but it's what I always do, and it works.
Assuming that you have an image that is exactly the same aize as your scene, you can do this:
// please declare bg as a class level variable
bg = SKSpriteNode(imageNamed: "name of your texture")
// the below two lines of code is my preference only. I want the
// background's anchor point to be the bottom left of the screen
// because IMO it's easier to add other sprites as children of the background.
bg.anchorPoint = CGPoint.zero
bg.position = CGPoint(x: self.frame.width / -2, y: self.frame.height / -2)
self.addChild(bg)
Alernatively, just do this in an sks file. It's much easier.
After that, add all your game sprites as children of bg instead of self because it is easier to manage.
I can't understand why the "strokeTexture" option isn't working on a SKShapeNode. Or, how can I do border with texture? Thanks in advance!
let shape = SKShapeNode(circleOfRadius: 100)
shape.position = CGPoint(x: 200, y: 400)
shape.fillColor = SKColor.white
shape.fillTexture = SKTexture(imageNamed: "test")
shape.lineWidth = 50
shape.strokeColor = SKColor.white
shape.strokeTexture = SKTexture(imageNamed: "test(5)")
Output:
Test image:
Test(5) image:
It doesn't work in Simulator!
Try it on your device.
I get the feeling this stroke might be being done with metal, whereas the fill is somehow not being done with metal, so is visible in the simulator.
The fill also doesn't rotate with the object on the device, but the stroke/outline and its texture do.
This would tend to indicate that an SKShapeNode without a fill might have reasonable performance.
Set the width and height of the texture, that is used to render the stroke, multiple of 8 pixels. In your case Test(5) has dimensions 100x100. If you change this texture for another one with dimensions, e.g. 96x96 pixels, the stroke will be rendered correctly and displayed. I don't know, why there are no reference to this fact in the official documentation.
I am trying to add a physicsBody to an SKShapeNode that is a rectangle. I built my PhysicsBody using fromEdgesWithLoop using the Node's frame as the CGRect to build it.
Using the debug option to show PhysicsBody, I see that it is actually not centered on my Sprite.
I searched the web to find that I should use this:
scene.scaleMode = .ResizeFill
Sadly, I tried all scaleModes and there are no differences.
I also verified my GameScene's size and it fits the iPad2 screen (my target), 1024x720.
The SKShapeNode is a child of the Scene.
I tried to set the position of my node in the center of the Scene before adding a PhysicsBody with its frame, but this changed nothing. The node was already in the center of the scene.
myShape.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
myShape.physicsBody = SKPhysicsBody(edgeLoopFromRect: myShape.frame)
The position of an Edge Loop is relative to the node it's attached to. In general, for an edgeLoopFromRect, the position is given by
edge_loop_position = node.position + rect.frame.origin
In this case, your physics body is offset by the position of myShape. One way to fix this issue is to attach the edge loop to the scene instead of the shape node:
self.physicsBody = SKPhysicsBody(edgeLoopFromRect: myShape.frame )
Alternatively, you can subtract the node's position from the frame's position with
let rect = CGRect(origin:CGPoint(x:myShape.frame.origin.x-myShape.position.x, y:myShape.frame.origin.y-myShape.position.y), size:myShape.frame.size)
myShape.physicsBody = SKPhysicsBody(edgeLoopFromRect:rect)