You’re making a SpriteKit game. You have a sprite on the screen. You run the game, and the sprite falls off the screen. Why is this happening? The answer is gravity. If you add a physics body to a sprite, it is initially affected by gravity. Gravity is a downward force. The game launches, and the sprite moves down. Because there’s nothing in the scene to stop the sprite’s downward movement, it moves off the screen.

If you have a game where the scene doesn’t scroll, you want to prevent the player from moving off the screen. SpriteKit constraints provide a nice way to keep the player on the screen at all times. Creating a Position Constraint Start by creating a range that specifies the lower and upper limits for a sprite’s position. Call the SKRange initializer and supply the lower and upper limits. The initializer for SKRange takes floating point values.

Many games have a need to generate random numbers. If you are making an iOS game with SpriteKit, the GameplayKit framework has classes for generating random numbers. Generating random numbers has two steps. Create a random number generator Generate a random number Creating a Random Number Generator Create an instance of GKRandomDistribution, which is GameplayKit’s class for generating random numbers. Supply the low and high values to define the range of numbers the generator can generate.

When you add a sprite to a SpriteKit scene from the scene editor, the only option is to create a sprite with a single color. A sprite with one color is OK for prototyping. But you’re going to eventually need to use real images for your sprite. Textures are the way to apply an image to a sprite so it looks like a spaceship, car, person, animal, or whatever your game needs.

In the Creating Your First SpriteKit Project article you created a game project in Xcode and removed Apple’s boilerplate code. Now you’re ready to start adding content to your game. Xcode’s scene editor is the tool most SpriteKit games use to add game content. Use Xcode’s scene editor to do things like build your game’s levels, design your game’s main menu, and create an end of game screen. Opening the Scene Editor Select a file with the extension .

Xcode playgrounds are good for prototyping game ideas, but if you want to get a SpriteKit game on your iPhone or iPad, you must create a project in Xcode. This article guides you through creating a SpriteKit project in Xcode. Choose the Game Project Template Launch Xcode and choose File > New > Project to create a project. When you choose File > New > Project the New Project Assistant opens.

I have seen many questions lately on Stack Overflow from people creating an iOS SpriteKit game project and having black bars on the edges of the screen. The cause of the issue is a bug in Xcode’s iOS game project template. When you create the project, the project does not include a storyboard for the launch screen. If you create a multiplatform game project, you will see a file called LaunchScreen.

Many iOS games use tap to move. Tap on the screen, and the player character will move to where you tapped. Use the SpriteKit action moveTo to add tap to move. Supply the destination location and the time interval (in seconds). When you run the action, the sprite will smoothly move to the destination over the time interval. func touchDown(atPoint pos : CGPoint) { let action = SKAction.move(to: pos, duration: 1.

When I see SpriteKit questions on Stack Overflow, I notice a common problem people make. They make every visible entity in their game, such as the player and enemies, a subclass of SKSpriteNode. They also add a property to the subclass for the sprite node. class Player: SKSpriteNode { var sprite: SKSpriteNode } Subclassing SKSpriteNode and having a property of SKSpriteNode is redundant. If you have a property for the sprite, you don’t need to subclass SKSpriteNode.

One thing most iOS games must do is handle touch input from the player. If you use SpriteKit, handling touch input isn’t too difficult. When you create a SpriteKit project or playground, the GameScene.swift file includes the following functions to handle touch input: touchesBegan touchesMoved touchesEnded touchesCancelled The two functions you’ll use the most are touchesBegan and touchesMoved. You use touchesBegan to handle taps and use touchesMoved to move a sprite with your finger.