SpriteKit: Removing gravity from SKSpriteNode doesn't work

Question

I'm trying to remove the gravity from SKSpriteNode but is not working. Here is my code:

I add add the SKSpriteNode:

let block: SKSpriteNode = self.childNode(withName: "block") as! SKSpriteNode

I add the gravity thru the Scene.sks

I tried all this ways to remove the gravity but none of the worked:

block.physicsBody?.affectedByGravity = false
block.physicsBody?.isDynamic = false
block.physicsBody?.velocity.dy = 0
block.physicsBody?.categoryBitMask = 0

How can I remove the gravity from SKSpriteNode ? any of you knows

I'll really appreciate your help.

Answer 1

It looks like (from the given code.) that your sprite is a color sprite in GameScene.sks. If so, this is an easy fix.

Just remove gravity from inside the GameScene.sks file:

Switch physics definition to none, or remove the tick from "Affected By Gravity"

If you are trying to remove gravity from the sprite in the code, correct me if I'm wrong, but I don't think you can. I prefer to set up the physics in my scene manually to avoid errors like this.

Answer 2

Only use the ? when you want to allow for a null/nil

block.physicsBody!.affectedByGravity = false
block.physicsBody!.isDynamic = false
block.physicsBody!.velocity.dy = 0
block.physicsBody!.categoryBitMask = 0

This will crash when physicsBody does not exist, which is what you want to be checking for (or you could do proper checks using guard.)

If this fails, you know that your block does not have a physics body (which would mean you are grabbing the wrong block.)

The question you need to ask yourself now is many block sprites exist in your scene, because the way your code is, it will only pull the first one it finds.

To disable all gravity on block sprites, you can do:

enumerateChildNodes(withName:"block")
{
    block,finished in
    block.physicsBody!.isDynamic = false
}

If our code is crashing at the spot where physicsBody is not nil, then we need to rethink of how our nodes are named, since it is not a good idea to have 2 different nodes with the same name.