SpriteKit changing SKAction for one Node

Question

I try to let the node moving faster after a specific System time. For example, after 30 seconds, the nodes move faster. In my Project it goes after the the BOOL Faster is true. With my Code, the nodes will move faster, but the ones, that already spawned, still using the old SKAction. So it looks weird, if there are 2 Nodes moving slower than the Node that is spawned. How can I fix that?

-(id)initWithSize:(CGSize)size {    
if (self = [super initWithSize:size]) {

..... 

SKAction * Spawn = [SKAction performSelector:@selector(Enemy) onTarget:self];
SKAction * Delay = [SKAction waitForDuration:1.5];
SKAction * SpawnThenDelay = [SKAction sequence:@[Spawn, Delay]];
SKAction * SpawnThenDelayForever = [SKAction repeatActionForever:SpawnThenDelay];
[self runAction:SpawnThenDelayForever];

.....
}

-(void)Enemy {

switch (arc4random_uniform(4)){

    case 0:
        if(Day){

            SKTexture * MenschSTexture1 = [SKTexture textureWithImageNamed:@"MenschSchwert1"];
            MenschSTexture1.filteringMode = SKTextureFilteringNearest;
            SKTexture * MenschSTexture2 = [SKTexture textureWithImageNamed:@"MenschSchwert2"];
            MenschSTexture2.filteringMode = SKTextureFilteringNearest;

            SKAction * Run = [SKAction repeatActionForever:[SKAction animateWithTextures:@[MenschSTexture1, MenschSTexture2] timePerFrame:0.25]];

            MenschSchwert = [SKSpriteNode spriteNodeWithTexture:MenschSTexture1];
            MenschSchwert.size = CGSizeMake(50, 50);
            MenschSchwert.zPosition = 2;

            MenschSchwert.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(15, 40)];
            MenschSchwert.physicsBody.dynamic = NO;
            MenschSchwert.physicsBody.allowsRotation = NO;
            MenschSchwert.physicsBody.usesPreciseCollisionDetection = YES;
            MenschSchwert.physicsBody.restitution = 0;
            MenschSchwert.physicsBody.velocity = CGVectorMake(0, 0);

            [MenschSchwert runAction:Run];

            MenschSchwert.physicsBody.categoryBitMask = HindernissCategory;
            MenschSchwert.physicsBody.collisionBitMask = BodenCategory | MenschCategory;
            MenschSchwert.physicsBody.contactTestBitMask = BodenCategory | MenschCategory;

            Feind = MenschSchwert;

            Feind.position = CGPointMake(self.frame.size.width * 1.25, Boden.position.y + 75);
        }

        if(Night){

            Zombie = [SKSpriteNode spriteNodeWithImageNamed:@"Zombie.png"];
            Zombie.size = CGSizeMake(50, 50);
            Zombie.zPosition = 2;

            Zombie.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(20, 40)];
            Zombie.physicsBody.dynamic = NO;
            Zombie.physicsBody.allowsRotation = NO;
            Zombie.physicsBody.usesPreciseCollisionDetection = YES;
            Zombie.physicsBody.restitution = 0;
            Zombie.physicsBody.velocity = CGVectorMake(0, 0);

            Zombie.physicsBody.categoryBitMask = HindernissCategory;
            Zombie.physicsBody.collisionBitMask = BodenCategory | MenschCategory;
            Zombie.physicsBody.contactTestBitMask = BodenCategory | MenschCategory;

            Feind = Zombie;

            Feind.position = CGPointMake(self.frame.size.width * 1.25, Boden.position.y + 75);
        }
        break;
    case 1:

        Steine = [SKSpriteNode spriteNodeWithImageNamed:@"Stein.png"];
        Steine.size = CGSizeMake(50, 55);
        Steine.zPosition = 2;

        Steine.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:10];
        Steine.physicsBody.dynamic = NO;
        Steine.physicsBody.allowsRotation = NO;
        Steine.physicsBody.usesPreciseCollisionDetection = YES;
        Steine.physicsBody.restitution = 0;

        Steine.physicsBody.categoryBitMask = HindernissCategory;
        Steine.physicsBody.collisionBitMask = BodenCategory | MenschCategory;
        Steine.physicsBody.contactTestBitMask = BodenCategory | MenschCategory;

        Feind = Steine;

        Feind.position = CGPointMake(self.frame.size.width * 1.25, Boden.position.y + 69);
        break;
    case 2:

        Block = [SKSpriteNode spriteNodeWithImageNamed:@"Block.png"];
        Block.size = CGSizeMake(40, 35);
        Block.zPosition = 2;

        Block.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(25, 25)];
        Block.physicsBody.dynamic = NO;
        Block.physicsBody.allowsRotation = NO;
        Block.physicsBody.usesPreciseCollisionDetection = YES;
        Block.physicsBody.restitution = 0;
        Block.physicsBody.velocity = CGVectorMake(0, 0);

        Block.physicsBody.categoryBitMask = LuftHindernissCategory;
        Block.physicsBody.collisionBitMask = MenschCategory;
        Block.physicsBody.contactTestBitMask = MenschCategory;

        Feind = Block;

        Feind.position = CGPointMake(self.frame.size.width * 1.25, Boden.position.y + 110);
        break;
    case 3:

        Stachel = [SKSpriteNode spriteNodeWithImageNamed:@"Stachel.png"];
        Stachel.size = CGSizeMake(60, 60);
        Stachel.zPosition = 2;

        Stachel.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(25, 25)];
        Stachel.physicsBody.dynamic = NO;
        Stachel.physicsBody.allowsRotation = NO;
        Stachel.physicsBody.usesPreciseCollisionDetection = YES;
        Stachel.physicsBody.restitution = 0;
        Stachel.physicsBody.velocity = CGVectorMake(0, 0);

        Stachel.physicsBody.categoryBitMask = LuftHindernissCategory;
        Stachel.physicsBody.collisionBitMask = MenschCategory;
        Stachel.physicsBody.contactTestBitMask = MenschCategory;

        Feind = Stachel;

        Feind.position = CGPointMake(self.frame.size.width * 1.25, Boden.position.y + 100);
        break;
    default:
        break;

}

if(Faster){

actionMove2 = [SKAction moveToX:-100 duration:4];
actionMoveDone2 = [SKAction removeFromParent];

[Feind runAction:[SKAction repeatActionForever:[SKAction sequence:@[actionMove2,actionMoveDone2]]]];

}

else{
actionMove = [SKAction moveToX:-100 duration:5];
actionMoveDone = [SKAction removeFromParent];

[Feind runAction:[SKAction repeatActionForever:[SKAction sequence:@[actionMove,actionMoveDone]]]];
}

[self addChild:Feind];

}

What do you mean by looks so weird? Does it look weird or behave strangely? — 0x141E
You need to cancel the old node's current SKAction and apply a new one with the updated speed. — sangony
Yes it seems so. Enemy spawns every 1.5 seconds, and after the 'faster' Action is used, the Nodes, that already spawned, move slower than the one that is spawned with the new Action. So the faster Node moves into the other nodes, which it shouldnt be. I want to avoid that. — user3452594

0x141E 0x141E · Accepted Answer · 2014-08-01T08:25:44

Replace your if statement with the following code...

if (Faster) {
    [self addActionToNode:Feind withDuration:4 andKey:@"faster"];
}
else {
    [self addActionToNode:Feind withDuration:5 andKey:@"slower"];
}

This method adds an action (with a key) to a node. The key allows you to find the slower nodes so they can be updated when the game speeds up.

- (void) addActionToNode:(SKSpriteNode *)node withDuration:(NSTimeInterval)duration andKey:(NSString *)key
{
    SKAction *move = [SKAction moveToX:-100 duration:duration];
    SKAction *remove = [SKAction removeFromParent];
    SKAction *action = [SKAction repeatActionForever:[SKAction sequence:@[move,remove]]];

    [node runAction:action withKey:key];

    if (!node.parent) {
        [self addChild:node];
    }
}

Call this to update the slower nodes when the game speeds up...

- (void) updateActions
{
    for (SKSpriteNode *node in self.children) {
        if ([node actionForKey:@"slower"]) {
            [node removeAllActions];
            [self addActionToNode:node withDuration:4 andKey:@"faster"];
        }
    }
}

SpriteKit changing SKAction for one Node

1 Answers