How to Improve SKEffectNode Performance (Swift)? - swift

so in my project I have an SKEffectNode that I use to provide a glow effect around some of my spriteNodes. I use a spriteNode (blurNode) to get the color of my obstacle and then give it to the effectNode. This works fine.
let blurNode = SKSpriteNode(imageNamed: "neonLine.png")
blurNode.color = obstacle.color
blurNode.colorBlendFactor = 1.0
blurNode.size = CGSize(width: obstacle.size.width + 30, height: obstacle.size.height + 30)
let effectNode = SKEffectNode()
effectNode.shouldRasterize = true
obstacle.addChild(effectNode)
effectNode.addChild(blurNode)
effectNode.filter = CIFilter(name: "CIGaussianBlur", withInputParameters: ["inputRadius":30])
effectNode.alpha = 1.0
My issue occurs here.
let colorFadegreen = SKAction.sequence([SKAction.colorize(with: UIColor(red: 0, green: 0.6471, blue: 0.3569, alpha: 1.0), colorBlendFactor: 1.0, duration: 3)])
obstacle.removeAllActions()
obstacle.run(colorFadegreen)
blurNode.removeAllActions()
blurNode.run(colorFadegreen)
What I want to do is have the "glow" that's around the obstacle change colors with the obstacle. That is exactly what happens; however, when I do so my frame rate drops down to 30fps.
So, my question is does anyone know how to improve the performance of this task? Or is there maybe another way I could go about doing this.
One of the ideas I thought of would be to manually blur the "neonLine.png" in photoshop and then add it to the blur node like so
let blurNode = SKSpriteNode(imageNamed: "bluredNeonLine.png"). The only thing is I can never get the blur right it always looks off.
Any help would be very much appreciated. Thanks!
EDIT:
Here are some photos of the glows in my project:
Here is the glow and lines changing color:

Three answers to the performance question with regards glows:
Use a pre-rendered glow, as per your mentioning in the question, done in Photoshop or similar bitmap editor, exported as bitmap with opacity and used as an SKSpriteNode texture, probably with additive blending for best results, and colour caste to taste.
Bake a texture of the SKEffectNode that's creating a desirable glow within SpriteKit by making it into a texture, and then loading it into an SKSpriteNode, as per this example: https://stackoverflow.com/a/40137270/2109038
Rasterise the results from your SKEffectNode and then hope your changes to colour casts don't cause re-rendering. This is shown in a wonderful extension, here: https://stackoverflow.com/a/40362874/2109038
In all cases, you're best off rendering a white glow that fades out as you like, and then applying colour blend changes to it, since SpriteKit has this built in, and it's reasonably performant in the few tests I've done. This is known as colorizing:
You can change and animate both the blend amount: https://developer.apple.com/reference/spritekit/skspritenode/1519780-colorblendfactor
and the color being blended with the texture: https://developer.apple.com/reference/spritekit/skspritenode/1519639-color

Related

SceneKit Node Lighting

I have a scenekit node that I want to add a glow effect to.
let newScene = SCNScene(named: "art.scnassets/cubeOne.scn")!
let newNode = (newScene.rootNode.childNode(withName: "cubeOneNode", recursively: false))!
newNode.geometry?.firstMaterial?.selfIllumination = UIColor.red
newNode.geometry?.firstMaterial?.ambientOcclusion = UIColor.red
sceneView.scene.rootNode.addChildNode(newNode)
You could achieve this by using a so called CIFilter and attach it to you node - but I personally don't recommend this, because it is incredibly performance intense and uses like three times more memory.
I recommend configuring this on your camera. It will also cost you more GPU performance and some memory, but not as much as a CIFilter does. Give it a try:
camera.wantsHDR = true
camera.bloomThreshold = 0.8
camera.bloomIntensity = 2
camera.bloomBlurRadius = 16.0
camera.wantsExposureAdaptation = false
and then use the emission.intensity property of the node material. Set it between 2.0 to 5.0, depending on how much you want the effect to be visible. I usually use the .physicallyBased lighting option for my on scene stuff. (I never tried to use it with selfIllumination.)
PS: Using the red color does not add a very intense effect. Really intense is cyan or green. Using the red color you might screw up the emission.intensity value to 10.0 or higher.

Is there a way to add a fading trail or stroke to a moving SKSpriteNode?

Still new, but slowly building my first app/game, and am slowly getting there.
I'd like to be able to add a fading streak or trail as one of my SKSpriteNodes moves. Whether it is moving due to touchesMoved or being sent back to its original spot by code. I just want to add a nice visual effect.
The only thing I can think of is calculating the distance, breaking it down into x movements, then gradually move the Sprite a little, with some fade options, and then repeat in a loop till it gets back to home base, using a lot of nested SKActions and sequences.
I know that has to be wrong because it's just so ugly.
When I look at the Sprite Kit's Particle File, it has so few options. And I'm not really sure that's what I should be looking at. I have also looked at SKAction's options, and if there's an option there I'm missing it.
Surely in Swift's huge animation library there has to be something?
Let's create a basic sprite and an emitter, and make the emitter a child of the sprite so that it follows it:
let sprite = SKSpriteNode(color: .white, size: CGSize(width: 20, height: 10))
let emitter = SKEmitterNode() // better to use the visual designer in Xcode...
emitter.particleLifetime = 1.0
emitter.particleBirthRate = 50.0
emitter.particleSpeed = 100.0
emitter.emissionAngleRange = .pi / 5
emitter.particleTexture = SKTexture(imageNamed: "spark")
emitter.particleScale = 0.1
emitter.particleAlphaSpeed = -1.0
emitter.emissionAngle = -.pi
sprite.addChild(emitter) // attach it to the sprite
emitter.position.x = -15 // but not to the center
scene.addChild(sprite)
sprite.run(SKAction.group([ // let's run some actions to test it:
SKAction.sequence([
SKAction.move(to: CGPoint(x: 200, y: 200), duration: 5),
SKAction.move(to: CGPoint(x: 50, y: 50), duration: 5),
]),
SKAction.rotate(byAngle: .pi * 2.0, duration: 10)
]))
(Click to open animated GIF if it doesn't display correctly:)
To the casual observer, it looks fine… Except that, after some scrutiny, you'll realize what's off: the particles emitted live in the universe of the parent sprite, moving and rotating with it, even long after they were emitted! That's not right!
That's because the targetNode of the emitter is its parent, and it should be the scene!
So let's insert this line somewhere:
emitter.targetNode = scene // otherwise the particles would keep moving with the sprite
(Click to open animated GIF if it doesn't display correctly:)
Okay, this is a no-go: the particles now stay in the "universe" of the scene, but apparently their emission angle fails to follow that of the parent (which looks like a bug to me).
Luckily, we can attach a custom action to the emitter which keeps aligning this angle to the parent sprite:
emitter.run(SKAction.repeatForever(
SKAction.customAction(withDuration: 1) {
($0 as! SKEmitterNode).emissionAngle = sprite.zRotation + .pi
_ = $1
}))
(Click to open animated GIF if it doesn't display correctly:)
Okay, now new particles are launched in the correct direction, and keep moving that way even if the sprite moves or rotates in the meantime. This seems to be the most realistic simulation so far, though there may still be ways to improve it by modifying the behavior of the emitter on the fly.
Sorry for the jaggy GIFs, apparently my Mac is too slow to render and capture at the same time. The animations themselves run just fine.

SKPhysicBodies appear to be slightly off-place

Edit: I have been able to solve this problem by using PhysicsEditor to make a polygonal physicsbody instead of using SKPhysicsBody(... alphaThreshold: ... )
--
For some reason I'm having trouble with what I'm assuming is SKPhysicBodies being slightly off-place. While using showPhysics my stationary obstacle nodes appear to have their physicbodies in the correct position, however I am able to trigger collisions without actually touching the obstacle. If you look at the image below it shows where I have found the physicsbodies to be off centre, despite showPhysics telling me otherwise. (Note, the player node travels in the middle of these obstacle nodes).
I also thought it would be worth noting that while the player is travelling, its physicbody appears to travel slightly ahead but I figured this is probably normal.
I also use SKPhysicsBody(... alphaThreshold: ... ) to create the physicbodies from .png images.
Cheers.
Edit: Here's how I create the obstacle physicbodies. Once they're added into the worldNode they are left alone until they need to be removed. Apart from that I don't change them in any way.
let obstacleNode = SKSpriteNode(imageNamed: ... )
obstacleNode.position = CGPoint(x: ..., y: ...)
obstacleNode.name = "obstacle"
obstacleNode.physicsBody = SKPhysicsBody(texture: obstacleNode.texture!, alphaThreshold: 0.1, size: CGSize(width: obstacleNode.texture!.size().width, height: obstacleNode.texture!.size().height))
obstacleNode.physicsBody?.affectedByGravity = false
obstacleNode.physicsBody?.isDynamic = false
obstacleNode.physicsBody!.categoryBitMask = CC.wall.rawValue
obstacleNode.physicsBody!.collisionBitMask = CC.player.rawValue
obstacleNode.physicsBody!.contactTestBitMask = CC.player.rawValue
worldNode.addChild(obstacleNode)
The player node is treated the same way, here is how the player moves.
playerNode.physicsBody?.velocity = CGVector(dx: dx, dy: dy)
I'm assuming you aren't showing the exact images that you used to create your SKSpriteNode and SKPhysicsBody instances. Since you are using a texture to define the shape of your SKPhysicsBody you are likely running up against this:
SKPhysicsBody documentation
If you do not want to create your own shapes, you can use SpriteKit to create a shape for you based on the sprite’s texture.
This is easy and convenient but it can sometimes give unexpected results depending on the textures you are using for your sprite. Perhaps try making an explicit mask or using a simple shape to represent your physics body. There are very good examples and guidelines in that documentation.
I would also follow this pattern when you set the properties on your objects:
// safely unwrap and handle failure if it fails
guard let texture = obstacleNode.texture else { return }
// create the physics body
let physicsBody = SKPhysicsBody(texture: texture,
alphaThreshold: 0.1,
size: CGSize(width: texture.size().width,
height: texture.size().height))
// safely set its properties without the need to unwrap an Optional
physicsBody.affectedByGravity = false
// set the rest of the properties
// set the physics body property on the node
obstacleNode.physicsBody = physicsBody
By setting the properties on a concrete instance of SKPhysicsBody and fully unwrapping and testing Optionals you minimize the chances for a run-time crash that may be difficult to debug.

Prevent SKPhysicsBody From Pushing SKSpriteNode Upwards

I currently have two SKSpriteNodes on top of each other like so (The white part is one and the brown round circle part is the other one):
The white part is positioned 1/3 the way down on top of the round brown sprite node. In the picture, the brown round part has a SKPhysicsBody applied to it already as seen by the light blue outline around it. When I add a SKPhysicsBody around the top ovalish white part it pushes it up and not in the position I wanted it.
How can I have a SKPhysics body coving both bodies of sprites but not have the physics bodies push on one another which makes the white part move upwards? I would like the white part to stay in the position it was in the first image.
Thanks for anyone help!
Here's the code I used for the SKPhysicsBody's:
// create, position, scale & add the round body
roundBody = SKSpriteNode( imageNamed: "roundBody" )
roundBody.position = CGPoint( x: 207, y: 70 )
roundBody.zPosition = 1
roundBody.xScale = 0.3
roundBody.yScale = 0.3
// add sprite node to view
self.addChild( roundBody )
// create, position, scale & add the head
theHead!.position = CGPoint( x: 207, y: roundBody.frame.maxY / 1.15 )
theHead!.zPosition = 2
theHead!.xScale = 0.3
theHead!.yScale = 0.3
// setting up a SKPhysicsBody for the round body
roundBody.physicsBody = SKPhysicsBody( circleOfRadius: roundBody.size.width / 4 )
roundBody.physicsBody!.dynamic = true
roundBody.physicsBody!.affectedByGravity = true
roundBody.physicsBody!.allowsRotation = false
roundBody.physicsBody!.pinned = false
// setting up a SKPhysicsBody for the head
theHead!.physicsBody = SKPhysicsBody(circleOfRadius: theHead!.size.width / 2 )
theHead!.physicsBody!.dynamic = true
theHead!.physicsBody!.affectedByGravity = false
theHead!.physicsBody!.allowsRotation = false
theHead!.physicsBody!.pinned = false
I was able to figure out that if you use SKPhysicsJointPin it does the exact thing I needed! (Which was to basically pin a sprite head on it's body and share a physics body)
let joinTogether = SKPhysicsJointPin.jointWithBodyA(
roundBody.physicsBody!,
bodyB:theHead!.physicsBody!,
anchor: GPointMake(CGRectGetMidX(roundBody.frame),
CGRectGetMinY(theHead!.frame)))
scene!.physicsWorld.addJoint(joint)
Hope this helps someone in the future!
If you never want it to move, set it's .dynamic property to false. Then other objects may or may not bounce/collide with it (depending upon their collisionBitMask) but it won't move in response to those collisions.
Your own answer is correct and a better solution but just to explain further.
The reason of the bodies colliding is that by default a physics body's collision bit mask is set to all categories which means it will collide with everything. In your code you are not calling
roundBody.physicsBody?.collisionBitMask = ...
which is why its using the default values.
To change that you could give your body and head a different collisionBitMask.
Im sure you will deal with this sooner or later when you handle collisions
Also as a tip it's a better idea to not force unwrap the physics bodies unless you have too, even though you know they exist. So you should replace your ! with ? whenever possible.

SpriteNode not rendered at first time when using atlases - works with xcassets

I have a very strange behaviour when rendering SKSpriteNodes using an atlas via imageNamed.
sprite = SKSpriteNode(imageNamed: triangle.triangleType1.spriteName)
sprite.size.height = TileHeight
sprite.size.width = TileWidth
sprite.zRotation = DegreesToRadians(triangle.rotation)
sprite.position = pointForColumn(triangle.column, row:triangle.row, columnOffset: TileWidth, rowOffset: TileHeight, tw: TileWidth,th: TileHeight)
triangleLayer.addChild(sprite)
triangle.sprite1 = sprite
addedTriangles++
print(sprite)
Some of those Sprites are not rendered adding them to the layer (another SKSpriteNode) for first time - printing the "sprite" shows that they're size 0,0 and the image shows "TrViolet" instead of "TrViolet#2x.png".
Other ones are rendered as they supposed to be.
Removing all the nodes and executing the same code for a second time DOES work though.
When I put the image in xcassets it works like a charm - even for the first time.
Is there any way to debug this kind of behavior or you have any idea on what might be happening here?