Simple collision in Sprite Kit

Question

I have two nodes. Player and Enemy. I want Enemy node to follow Player node once it's close enough and Enemy node would stop when it collides with Player node. And what I get is Enemy node goes on top of Player and both nodes gets pushed. I thought about somehow stopping Enemy node from moving on collision with Player but it seems to me like it should be a cleaner way.

(I move Enemy node by changing it possition on Update).

Here's my GameScene.sks:

-(void)didMoveToView:(SKView *)view {

    player = [self childNodeWithName:@"character"];
    enemy  = [self childNodeWithName:@"enemy"];
    self.physicsWorld.contactDelegate = self;
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    for (UITouch *touch in touches) {
        moveToTouch = [touch locationInNode:self];
        SKNode *tile = [self nodeAtPoint:moveToTouch];
        if([tile.name isEqualToString:@"tile"])
        {
            moveToTouch = tile.position;
        }
    }
}

-(void)update:(CFTimeInterval)currentTime {

    [self walk:player to:moveToTouch];

    if((SDistanceBetweenPoints(enemy.position, player.position) < 200))
    {
        [self walk:enemy to:player.position];
    }


}

-(void)walk:(SKNode*)node to:(CGPoint)moveTo
{
    if (CGPointEqualToPoint(moveTo, CGPointZero))
    {
        return;
    }


    if(round(moveTo.y) != round(node.position.y))
    {

        if(moveTo.y > node.position.y)
        {
            node.position = CGPointMake(node.position.x,node.position.y+2);
        }
        else if (moveTo.y < node.position.y)
        {
            node.position = CGPointMake(node.position.x,node.position.y-2);
        }

    }else if(round(moveTo.x) != round(node.position.x))
    {

        if(moveTo.x > node.position.x)
        {
            node.position = CGPointMake(node.position.x+2,node.position.y);
        }
        else if (moveTo.x < node.position.x)
        {
            node.position = CGPointMake(node.position.x-2,node.position.y);
        }

    }

    float distance = SDistanceBetweenPoints(node.position, moveTo);
    if (distance < 1.0){
        moveToTouch = CGPointZero;
    }

}

Answer 1

I don't know how you have it set up that your enemy follows the player. But you could try to

• set the enemy dynamic to false
• or put velocity to 0

Use collision detection to know when the collided.