I am trying to join two SKPhysicsBodies together so that the one on top stays in place and the one below falls with gravity but is attached with a joint. Imagine two rectangles, one on top and one below. The one on top stays in place "floating" and the one below is attached with a joint and can move (swing perhaps or bounce etc)
When I attempt to create this, both nodes fall with gravity even if I set the affectedByGravity to NO.
self.backgroundColor = [SKColor colorWithRed:0.15 green:0.15 blue:0.3 alpha:1.0];
self.physicsWorld.gravity = CGVectorMake(0, -9.8);
SKLabelNode *myLabel = [SKLabelNode labelNodeWithFontNamed:#"myFont"];
myLabel.text = #"Hello, World!";
myLabel.fontSize = 30;
myLabel.position = CGPointMake(CGRectGetMidX(self.frame),
CGRectGetMidY(self.frame));
myLabel.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:myLabel.frame.size];
myLabel.physicsBody.affectedByGravity = NO;
[self addChild:myLabel];
SKLabelNode *myLabel2 = [SKLabelNode labelNodeWithFontNamed:#"myFont"];
myLabel2.text = #"Hello, World!";
myLabel2.fontSize = 30;
myLabel2.position = CGPointMake(CGRectGetMidX(self.frame),
CGRectGetMidY(self.frame));
myLabel2.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:myLabel2.frame.size];
[self addChild:myLabel2];
CGPoint anchor = CGPointMake(CGRectGetMidX(self.frame),
CGRectGetMidY(self.frame));
SKPhysicsJointFixed* fixedJoint = [SKPhysicsJointFixed jointWithBodyA:myLabel.physicsBody
bodyB:myLabel2.physicsBody
anchor:anchor];
[self.scene.physicsWorld addJoint:fixedJoint];
You can set the dynamic property of the static body to NO, and that will cause the body to ignore all forces and impulses, including gravity.
Related
I have rectangle shape paddle node, my question is - is it possible to "cut" node in half so when, for example ball, hit right side of node ball will go back with bigger angle, that it came, and same thing on other side. Im bad with words so, here are image of what I want to do :
For paddle node i use this code:
paddle = [[SKSpriteNode alloc] initWithImageNamed: #"board.png"];
paddle.name = paddleCategoryName;
paddle.position = CGPointMake(self.frame.origin.x + 50, CGRectGetMidY(self.frame));
[self addChild:paddle];
paddle.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:paddle.frame.size];
paddle.physicsBody.restitution = 0.1f;
paddle.physicsBody.friction = 0.4f;
paddle.physicsBody.dynamic = NO;
and for ball :
ball = [SKSpriteNode spriteNodeWithImageNamed: #"ball.png"];
[self addChild:ball];
ball.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:ball.size.width];
ball.physicsBody.friction = 0.0f;
ball.physicsBody.restitution = 1.0f;
ball.physicsBody.linearDamping = 0.0f;
ball.physicsBody.allowsRotation = NO;
I have two body
SKShapeNode *hero = [SKShapeNode shapeNodeWithCircleOfRadius:HERO_SIZE];
hero.lineWidth = 1;
hero.fillColor = [SKColor orangeColor];
hero.name = #"Hero";
hero.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:HERO_SIZE];
hero.physicsBody.categoryBitMask = hero;
hero.physicsBody.collisionBitMask = friendlyCategory | enemyCategory;
hero.physicsBody.contactTestBitMask = friendlyCategory | enemyCategory;
hero.position = [self getStartPosition];
SKShapeNode *circle = [SKShapeNode shapeNodeWithCircleOfRadius:BALL_SIZE];
circle.position = [self randomPossition];
circle.lineWidth = 2;
circle.strokeColor = [SKColor blueColor];
circle.fillColor = color;
circle.name = #"Circle";
circle.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:BALL_SIZE];
circle.physicsBody.categoryBitMask = friendlyCategory;
circle.physicsBody.collisionBitMask = hero;
circle.physicsBody.contactTestBitMask = hero;
then,
- (void)didEndContact:(SKPhysicsContact *)contact
{
uint32_t collision = (contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask);
if (collision == (friendlyCategory | hero ))
{
SKShapeNode* node = (SKShapeNode*)contact.bodyA.node;
if ([node.name isEqualToString:#"Hero"])
{
self.activeFriendlyBall = (SKShapeNode*)contact.bodyB.node;
}
else
{
self.activeFriendlyBall = (SKShapeNode*)contact.bodyA.node;
}
self.hero.position = self.activeFriendlyBall.position;
}
}
Hero must be added above activeFriendlyBall, for him center position. But it added near him. I think it because physic body added. But I need to use physic body for other logic.
http://cl.ly/image/0g1S0d3h1h0w
must be like, how in top screen.
I find solution.
self.heroBall.physicsBody.velocity = CGVectorMake(0, 0);
[self.heroBall runAction: [SKAction moveTo:self.activeFriendlyBall.position duration:0.0]];
I believe it is because you have collision detection enabled for both, which means they can't be put on top of one another. If you are just trying to determine if one sprite comes into contact with another all you need is the contact detection. Removing either hero or friendlyball from the collision detection bit mask will allow them to be placed on top of each other/go through each other etc.
If you don't care about collisions at all for one of them (the sprite doesn't 'bounce' off anything) I'd recommend just setting collision detection to 0 for that sprite.
Best
I can't seem to get a unmovable fixed floor / wall in Sprite Kit.
I have a scene which has an SKNode as a "floor" and when the user presses the screen, a block drops from the touched position onto the "floor". That works well, but when the user adds another lets say 20 blocks or so, suddenly the floor rotates.
This is the code for my Floor:
SKSpriteNode *floorNode = [[SKSpriteNode alloc] initWithColor:[SKColor clearColor] size:CGSizeMake(self.size.width*2, 10)];
floorNode.position = CGPointMake(CGRectGetMidX(self.frame), -5);
floorNode.name = #"floor";
floorNode.zPosition = 1;
floorNode.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:floorNode.size];
floorNode.physicsBody.affectedByGravity = NO;
floorNode.physicsBody.dynamic = NO;
floorNode.physicsBody.usesPreciseCollisionDetection = YES;
return floorNode;
Sorry i'm quite new to Sprite Kit. Does anyone know what's wrong with my code?
EDIT: I've added some images to make the problem a bit more clear. Since it happens in this screen also. Those black spheres you see are flying from left to right like a canonball. I increased the amount of spheres to show the problem occurring. This is the code:
- (SKNode *)newEditButton {
SKLabelNode *editButtonNode = [SKLabelNode labelNodeWithFontNamed:#"chalkduster"];
editButtonNode.text = #"EDIT CASTLE";
editButtonNode.fontSize = 19;
editButtonNode.fontColor = [SKColor darkGrayColor];
editButtonNode.position = CGPointMake(CGRectGetMidX(self.frame) + 110, CGRectGetMidY(self.frame) + 30);
editButtonNode.name = #"edit_button";
editButtonNode.zPosition = 2;
editButtonNode.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(140, 40)];
editButtonNode.physicsBody.usesPreciseCollisionDetection = YES;
editButtonNode.physicsBody.dynamic = NO;
editButtonNode.physicsBody.affectedByGravity = NO;
SKAction *hover = [SKAction sequence:#[[SKAction moveByX:0 y:6.0 duration:0.9],
[SKAction moveByX:0 y:-6.0 duration:0.9]]];
SKAction *hoverForever = [SKAction repeatActionForever:hover];
[editButtonNode runAction:hoverForever];
return editButtonNode;
}
- (SKNode *)newPlayButton {
SKLabelNode *playButtonNode = [SKLabelNode labelNodeWithFontNamed:#"chalkduster"];
playButtonNode.text = #"SLAUGHTER";
playButtonNode.fontSize = 19;
playButtonNode.fontColor = [SKColor darkGrayColor];
playButtonNode.position = CGPointMake(CGRectGetMidX(self.frame) - 110, CGRectGetMidY(self.frame) + 30);
playButtonNode.name = #"play_button";
playButtonNode.zPosition = 2;
playButtonNode.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(140, 40)];
playButtonNode.physicsBody.usesPreciseCollisionDetection = YES;
playButtonNode.physicsBody.dynamic = NO;
playButtonNode.physicsBody.affectedByGravity = NO;
SKAction *hover = [SKAction sequence:#[[SKAction moveByX:0 y:6.0 duration:0.9],
[SKAction moveByX:0 y:-6.0 duration:0.9]]];
SKAction *hoverForever = [SKAction repeatActionForever:hover];
[playButtonNode runAction:hoverForever];
return playButtonNode;
}
After a while 5-10 seconds, the "buttons" called "slaughter" and "edit castle" start to rotate everytime a sphere collides with it. But it doesn't seem like it has to do something with physics, because, if it rotates to the left, it's rotation direction will always be left. And if it starts rotating right, it's rotation direction will always be right.
It looks funny though! But not what i want ;-)
You don't know it, but you're telling SpriteKit to apply collisions from the cannonballs to the labels, and from the blocks to the floor!
That's because you're leaving SKPhysicsBody.collisionBitMask to its default value, which is to observe collisions for everything.
From the documentation:
Discussion
When two physics bodies contact each other, a collision may occur. This body’s collision mask is compared to the other body’s category mask by performing a logical AND operation. If the result is a nonzero value, this body is affected by the collision. Each body independently chooses whether it wants to be affected by the other body. For example, you might use this to avoid collision calculations that would make negligible changes to a body’s velocity.
The default value is 0xFFFFFFFF (all bits set).
So, do:
floorNode.physicsBody.collisionBitMask = 0
I'm kind of new with SpriteKit and I'm having some troubles with the physics, I've tried many things to make a SKSpriteNode move with a force or an impulse but it never moves, only gravity affects it when i set it.
-(id)initWithSize:(CGSize)size {
if (self = [super initWithSize:size]) {
self.anchorPoint = CGPointMake(0.5, 0.5);
myWorld = [SKNode node];
[self addChild:myWorld];
SKSpriteNode* map = [SKSpriteNode spriteNodeWithImageNamed:#"grass"];
[myWorld addChild:map];
self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:map.frame];
self.physicsBody.friction = 0.0f;
self.physicsBody.categoryBitMask = 2;
self.physicsWorld.gravity = CGVectorMake(0.0, 0.0);
self.physicsWorld.contactDelegate = self;
pointOfView = [SKSpriteNode spriteNodeWithColor:[UIColor colorWithWhite:1 alpha:0.2] size:CGSizeMake(300, 548)];
[myWorld addChild:pointOfView];
pointOfView.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:pointOfView.frame.size];
pointOfView.physicsBody.friction = 0.0f;
pointOfView.physicsBody.restitution = 1.0f;
pointOfView.physicsBody.linearDamping = 0.0f;
pointOfView.physicsBody.allowsRotation = NO;
pointOfView.physicsBody.collisionBitMask = 2;
pointOfView.physicsBody.categoryBitMask = 3;
[pointOfView.physicsBody applyImpulse:CGVectorMake(10.0f, -10.0f)];
}
return self;
}
Here is most of my code in my main scene, there's nothing else except some empty methods like update or touchesBegan.. Am I missing something ? I've tried so many things, i'm starting to lose it haha
Thanks very much for any help !
It's a bit late, but the answer is here: Not able to apply impulse to SKSpriteNode physics body
The problem is that you've created a physics body with bodyWithEdgeLoopFromRect; this creates a static physics body which won't respond to applyImpulse. You need to add the physics body using bodyWithRectangleOfSize: instead.
pointOfView.physicsBody.dynamic = YES;
The dynamic property decides if a sprite should be affected by physics forces.
you have written wrong code your pointOfView not affected by gravity you are just applying a small impusle on it.
change this line self.physicsWorld.gravity = CGVectorMake(0.0, 0.0) to self.physicsWorld.gravity = CGVectorMake(0.0, -9.8); if u looking for negative gravity towards up direction and CGVectorMake(0.0, 9.8) if you looking for positive gravity towards downwards. and try to apply impulse after a interval [pointOfView.physicsBody applyImpulse:CGVectorMake(10.0f, -10.0f)];
I'm not sure if I'm correct in wording it "modal sprite-kit scene" but what I'm trying to do is have a smaller sized scene appear over a scene when the game is complete. Attached is a screenshot to show what I mean:
The screenshot is from Flappy Bird where when the player dies, the small game-over scene pops up almost like a modal effect, and displays the user's final results. I was wondering how to go about creating this.
I tried calling this when the game was done:
[self.player runAction:death completion:^{
[self removeAllActions];
GameOverNode *gameOverNode = [[GameOverNode alloc] initWithScore:self.size];
gameOverNode.gameScene = self;
gameOverNode.position = CGPointMake(self.scene.size.width/2, -150);
[self addChild:gameOverNode];
[gameOverNode runAction:[SKAction moveToY:self.scene.size.height/2 duration:0.6]];
And this was the code for the gameOverNode in the gameOverScene.m's file:
-(id)initWithSize:(CGSize)size {
if (self = [super initWithSize:size]) {
self.userInteractionEnabled = YES;
self.zPosition = 20;
SKSpriteNode *bg = [SKSpriteNode spriteNodeWithColor:[UIColor blackColor] size:CGSizeMake(280*DoubleIfIpad, 300*DoubleIfIpad)];
bg.alpha = 0.55;
But the node only shows up in the bottom left hand corner of the screen, as opposed to in the middle like I want it too.
What am I doing wrong? How can I make the small gameover node pop up and sit in the middle of the scene.
You simply can't. According to Apple Docs and multiple StackOverflow posts you cannot be running two SKScene's at the same time. To recreate the effect you want, you can create an SKShapeNode with border and line color similar to those you want, and place objects like score inside, or you can create an image for the screen that pops up and just add SKLabelNodes to the scene that show the high score and current score. I'm attaching a picture of how I created an end "view" for my app, Average Guy.
I made the popup screen using an SKShapeNode like this:
SKShapeNode *optionsMenu = [SKShapeNode node];
CGRect tempRect = CGRectMake(SELF_WIDTH/2, SELF_HEIGHT/2, SELF_WIDTH-20, (finalScoreLabel.position.y+(finalScoreLabel.frame.size.height/2)) - (mainMenuButton.position.y-(mainMenuButton.frame.size.height/2)) + 20);
CGPathRef tempPath = CGPathCreateWithRoundedRect(CGRectMake(tempRect.origin.x - tempRect.size.width/2, tempRect.origin.y - tempRect.size.height/2, tempRect.size.width, tempRect.size.height), 5, 5, Nil);
optionsMenu.path = tempPath;
optionsMenu.fillColor = [SKColor grayColor];
optionsMenu.strokeColor = [SKColor blueColor];
optionsMenu.zPosition = 30;
optionsMenu.glowWidth = 2.0f;
CGPathRelease(tempPath);
Of course, don't mind the hectic CGRect implementation, I wanted to make everything relative to fit all of the screen sizes so I didn't hardcode any of the positions. As for adding the score and the buttons, I did this:
SKLabelNode *restartButton = [SKLabelNode labelNodeWithFontNamed:#"00 Starmap Truetype"];
restartButton.text = #"Play Again";
restartButton.zPosition = 31;
restartButton.fontColor = [SKColor blueColor];
restartButton.fontSize = 30;
restartButton.position = CGPointMake(HALF_WIDTH, HALF_HEIGHT-50);
restartButton.name = #"restart_button";
SKLabelNode *restartButtonShadow = restartButton.copy;
restartButtonShadow.position = CGPointMake(restartButton.position.x+1, restartButton.position.y-1);
restartButtonShadow.color = [SKColor colorWithRed:0 green:0 blue:.5 alpha:.1];
SKLabelNode *mainMenuButton = [SKLabelNode labelNodeWithFontNamed:#"00 Starmap Truetype"];
mainMenuButton.text = #"Main Menu";
mainMenuButton.zPosition = 31;
mainMenuButton.fontColor = [SKColor blueColor];
mainMenuButton.fontSize = 30;
mainMenuButton.position = CGPointMake(HALF_WIDTH, HALF_HEIGHT - 85);
mainMenuButton.name = #"main_menu_button";