I recently came across an issue where I would increase the size of a node, but the physics body would remain the same size. I tried to look up solutions to this with no success. How can I make the body scale with the size of the node?
CGPoint location = CGPointMake(randX, -self.frame.size.height - expander.size.height);
SKAction *moveAction = [SKAction moveTo:location duration:randDuration];
SKAction *expandAction = [SKAction resizeToWidth:(expander.size.width * 1.4) height:(expander.size.width * 1.4) duration:1.0];
SKAction *collapseAction = [SKAction resizeToWidth:(expander.size.width) height: (expander.size.height) duration:1.0];
SKAction *doneAction = [SKAction runBlock:(dispatch_block_t)^() {
expander.hidden = YES;
}];
SKAction *expandCollapseAction = [SKAction repeatActionForever:[SKAction sequence:#[expandAction, collapseAction]]];
SKAction *moveExpandAction = [SKAction group:#[moveAction, expandCollapseAction]];
SKAction *moveExpanderActionWithDone = [SKAction sequence: #[moveExpandAction, doneAction ]];
[expander runAction:moveExpanderActionWithDone withKey: #"expanderMoving"];
I thought this won't work, but it looks like that physics body is scaled after all. Here is the code which can reproduce physics body scaling on iOS8 :
- (void)didMoveToView:(SKView *)view {
/* Setup your scene here */
SKSpriteNode *s = [SKSpriteNode spriteNodeWithColor:[SKColor yellowColor] size:CGSizeMake(100,100)];
s.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMinY(self.frame)+100);
s.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:s.size];
s.physicsBody.dynamic = YES;
s.physicsBody.affectedByGravity = NO;
[self addChild:s];
[s runAction:[SKAction scaleTo:0.3f duration:5]];
[s.physicsBody applyImpulse:CGVectorMake(0,30)];
}
If I recall correctly , this wasn't worked earlier, but I just tried it and it looks like it work. Still, this is not fully tested and I am not sure if this will mess up the physics simulation. Contact detection will probably work though. I just wanted to show that actual physics bodies are scaled when sprite is scaled . Here is the result:
From the gif above it can be seen that physics body is scaled along with sprite (without re-creating another different sized physics body). The blue bounding box around the sprite is visual representation of sprite's physics body (enabled in view controller with skView.showsPhysics = YES);
this is strange you can do it add physics body before adding it to the SKNode or SKScene for e.g.
SKTexture *texture=[_gameTexture textureNamed:#"mysprite"];
SKSpriteNode *bubble=[SKSpriteNode spriteNodeWithTexture:texture];
bubble.anchorPoint=CGPointMake(0.5,0.5);
//_bubble.name=[#"bubble" stringByAppendingFormat:#"%d ",index];
bubble.name=newcolor;
// _bubble.userInteractionEnabled=YES;
_bubble.position=CGPointMake(newPosition.x, newPosition.y);
//
bubble.physicsBody=[SKPhysicsBody bodyWithCircleOfRadius:60];
bubble.physicsBody.dynamic=NO;
bubble.physicsBody.linearDamping=0;
bubble.physicsBody.restitution=0;
bubble.physicsBody.density=1;
bubble.physicsBody.allowsRotation=NO;
bubble.physicsBody.affectedByGravity=NO;
//_bubble.physicsBody.velocity=CGVectorMake([self getRandomNumberBetween:-10 to:7], [self getRandomNumberBetween:-10 to:7]);
// _bubble.physicsBody.usesPreciseCollisionDetection=YES;
bubble.physicsBody.categoryBitMask=ballCategory;
bubble.physicsBody.collisionBitMask=ballCategory | pathCategory ;
bubble.physicsBody.contactTestBitMask=ballCategory | pathCategory ;
[self addChild:_bubble];
bubble.xScale=_bubble.yScale=2;
bubble.alpha=0.5;
Related
I have two nodes one near another. And I want one node to be on top of another when I tap. I do so like this:
SKAction *moveUp= [SKAction moveByX:0 y:25 duration:0.1];
SKAction *moveDown= [SKAction moveByX:0 y:-25 duration:0.1];
SKAction *playerSequence = [SKAction sequence:#[moveUp,moveDown]];
[self.player runAction:[SKAction repeatAction:playerSequence count:1] withKey:#"attack"];
And instead I get that one node pushes the other (bots nodes created via editor and both body type is set to none).
I tried adding these to didMoveToView on both nodes:
node.physicsBody.dynamic = NO;
node.physicsBody.collisionBitMask = 0;
node.physicsBody.contactTestBitMask = 0;
node.physicsBody.affectedByGravity = NO;
I even tried setting velocity to 0 on Update. And still no effect.
Set your bit masks in
-(void)didBeginContact:(SKPhysicsContact *)contact
as shown in this post.
I think you have a timing issue if you set the bit masks in
didMoveToView
because only one of those will be run at a time and both physics bodies will need to mutually agree not contact each other.
You have to set the physics body to nil:
node.physicsBody = nil;
I am building a platform game in Xcode 6.0 using Sprite Kit. The problem that I have is related to the "monster sprite node" which are created by the following method
-(void) generateMonster {
monster = [SKSpriteNode spriteNodeWithImageNamed:#"monster.png"];
monster.name = #"monster";
monster.size = CGSizeMake(monster.frame.size.width, monster.frame.size.height);
monster.position = CGPointMake(self.currentMonsterX, ground.position.y + monster.frame.size.height);
monster.zPosition = 3.0;
monster.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:monster.size];
monster.physicsBody.categoryBitMask = monsterCategory;
SKAction *moveRight = [SKAction moveByX:30.0 y:0 duration:1.0];
SKAction *moveLeft = [SKAction moveByX:-30.0 y:0 duration:0.5];
SKAction *pulseMovement = [SKAction sequence:#[moveRight, moveLeft]];
[monster runAction:[SKAction repeatActionForever:pulseMovement]];
[self.world addChild:monster];
self.currentMonsterX += (arc4random() % 400) + 100;
}
the position of monster in the debugging is OK "about 50.0", but when it placed to the other SKNode *World which contains all other contents like clouds, stars and hero, the monster.position.y gets a negative value which moves it way below "about -9000"!!?
Any help is appreciated.
My bad ..
I had a little logic mistake in the order of creation .. Here is what I was doing, just in case someone else stuck with the same mistake.
The problem was in the code line:
monster.position = CGPointMake(self.currentMonsterX, ground.position.y + monster.frame.size.height);
Precisely at "ground.position.y" since the node "ground" was not yet created and hence the monsters were falling and thus the -9000 or lower.
Sorry about that.
I am having trouble getting collision detection to work with my two objects. Here is my current code:
_firstPosition = CGPointMake(self.frame.size.width * 0.817f, self.frame.size.height * .40f);
_squirrelSprite = [SKSpriteNode spriteNodeWithImageNamed:#"squirrel"];
_squirrelSprite.position = _firstPosition;
_atFirstPosition = YES;
[self addChild:_squirrelSprite];
SKAction *wait = [SKAction waitForDuration:3.0];
SKAction *createSpriteBlock = [SKAction runBlock:^{
SKSpriteNode *lightnut = [SKSpriteNode spriteNodeWithImageNamed:#"lightnut.png"];
BOOL heads = arc4random_uniform(100) < 50;
lightnut.position = (heads)? CGPointMake(257,600) : CGPointMake(50,600);
[self addChild: lightnut];
SKAction *moveNodeUp = [SKAction moveByX:0.0 y:-700.0 duration:1.3];
[lightnut runAction: moveNodeUp];
}];
SKAction *waitThenRunBlock = [SKAction sequence:#[wait,createSpriteBlock]];
[self runAction:[SKAction repeatActionForever:waitThenRunBlock]];
I was following this answer at first: Sprite Kit Collision Detection but when I set the physics body to my squirrel and nut they would just fall. Is there any way to not mess with the physics (I'm happy with how everything currently works in the app) and just make it so that when one object touches the other the game will end? Is there a way to just set a radius around a sprite? Thank you for any help or information that can be provided.
Physics bodies are required for collision detection. If you don't also want gravity, either set the physics world's gravity to zero or turn off the affectedByGravity property on each physics body.
You can use the Pythagorean theorem to determine the distance between two sprite nodes. Here's an example of how to do that:
CGFloat dx = sprite1.position.x - sprite2.position.x;
CGFloat dy = sprite1.position.y - sprite2.position.y;
CGFloat distance = sqrt(dx*dx+dy*dy);
// Check if the two nodes are close
if (distance <= kMaxDistance) {
// Do something
}
I'm creating an ongoing learning project (basically I code while learning to use the framework in hope it will be useful for me and for someone else) for Sprite Kit (you can find it here if you are interested) but I'm facing some performance problems with my code.
The project puts cubes on the screen and make them falling. Here's the class that creates the piece
// The phisics for our falling piece:
// It will be a square, subject to gravity of 5: check common.h (9.8 is way too much for us)
self.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(self.size.width, self.size.height)];
self.physicsBody.dynamic = YES;
self.physicsBody.mass = 100;
self.physicsBody.collisionBitMask = piecesCollisionBitmask;
self.physicsBody.allowsRotation = NO;
and here is the scene file with the loop.
//schedule pieces
SKAction *wait = [SKAction waitForDuration:1];
SKAction *pieceIsFalling = [SKAction runBlock:^{
FLPPiece *piece = [[FLPPiece alloc] init];
[self addChild:piece];
}];
SKAction *fallingPieces = [SKAction sequence:#[wait,pieceIsFalling]];
[self runAction:[SKAction repeatActionForever:fallingPieces]];
I suspect that physics is behind my frame rate drop. I would like to stop physics execution on node while keeping it on the screen as soon as it collides with something else.
Is that possible? How can I do that?
I'm working in IOS/spritekit where I have a sprite that rotates. The rotation works fine, but in addition I want that the sprite jumps. Therefore I added dynamic and restitution to my physicsBody of my sprite:
SKSpriteNode *sprite = [SKSpriteNode spriteNodeWithImageNamed:#"bigball"];
sprite.position = location;
sprite.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:sprite.size.width/2];
sprite.physicsBody.dynamic = YES;
sprite.physicsBody.restitution = 0.7;
SKAction *action = [SKAction rotateByAngle:M_PI duration:1];
[sprite runAction:[SKAction repeatActionForever:action]];
This also works, but the sprite only jumps 2 times and then comes to a standstill, which is logical because I've added the dynamic, but I want that the sprite jumps infinitely.
Can anyone explain how I can do it?
Thanks in advance
Try this:
sprite.physicsBody.restitution = 1.0;
If the restitution property is at 1.0, its bounciness will be at the maximum level - the physics body will not lose any energy while bouncing, so it should bounce indefinitely.