Scaling Physics Bodies in Xcode Spritekit

Scale a SKPhysicsBody, how?

If you assign a physics body to a sprite and scale that sprite, the physics body will scale with it.

SKAction scale physicsBody

If you set the size of the physicsbody to the size of the circle, you may achieve what you seek.

_circle = [SKSpriteNode spriteNodeWithImageNamed:@"cirlce"];
_circle.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:_circle.size.width/2];

Increasing the size of a spriteNode using spriteKit in update function (Swift)

Whoever told you to not use SKActions is wrong. This is exactly when you want to use an SKAction, and if you have multiple circles pulsing, you use the same action on all circles.

You really want to keep your update function as small as possible. Trust in apple’s optimizations because they have better access to the API than you do.

Change SpriteNode PhysicsBody Size at Run Time

According to SpriteKit documentation the area of a SKPhysicsBody can't be modified, so you need to create another SKPhysicsBody instance and copy the values you want to keep from the previous instance.

SpriteKit: Physics bodies breaking under too much force (applyForce)

The higher the nodes with physics bodies, the lower the framerate.

The lower the framerate, the crazier the engine gets. One time I've even see it make some kind of blackhole.

It'll help if you lessen the force against the wall, whether gravity, or velocity from applyforce. Also making sure there's enough space for them will help.

Using precise collision detection will even lessen the framerate further.

SpriteKit help understanding scaling

iPhone 6 is close enough in resolution to iPhone 5 that it's meant to use 2x images.

1136 x 640 - iphone5

1334 x 750 - iphone 6

Because your background is 640 pixels tall, it will have some space missing on the top and bottom in portrait mode. You need to make a background with areas that you don't mind being cut off on smaller devices (iphone 4 and 5). Or you need to have a black frame around your game on the iphone 6. I wouldn't recommend scaling every image..

This was a common issue even before iphone 6 was around. This image kind of shows what I'm talking about

http://cdn5.raywenderlich.com/wp-content/uploads/2013/09/Aspect-Ratio-Diff.jpg

Image Sizes

You need three image sizes.

@2x = iphone4s, 5, 5s, 6 (you use this for non retina ipads as well)

@3x (1.5 * 2x) = iphone 6 PLUS

@2x~ipad (2 * 2x) = ipad retina and retina mini

the way you want to organize this is up to you. In my game I split my images up into two sets of atlases. one for iPad and one for Iphone.

My way of organizing my atlases

Images with no suffix are for the non-retina ipads.

In my code I have a simple function to decide which texture atlas I want to load.

func getTextureAtlas(filename: String) -> SKTextureAtlas {
    var name = filename
    if UIDevice.currentDevice().userInterfaceIdiom != .Phone {
        name = "\(name)-ipad"
    }

    return SKTextureAtlas(named: name)
}

example useage:

shipAtlas = getTextureAtlas("ship")

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