I have the same problem like here: SKSpriteKit, detect non-transparency parts
My post is deleted from there. I don't know why, in other forums, THIS is a double post!!!
But ok, if you like that. Poor danny who still have not the answer!
Ok well, here comes the question again:
There are two png files with transparent areas. Like in the post of danny huang.
If they collide the "-(void)didBeginContact:(SKPhysicsContact *)contact" method fire.
But what we looking for is that they just collied with the non-transparent areas of the image.
Here is a small code snipped:
...
SKTexture *nyanTexture1 = [SKTexture textureWithImageNamed:#"test.png"];
nyanTexture1.filteringMode = SKTextureFilteringNearest;
nyan = [SKSpriteNode spriteNodeWithTexture:nyanTexture1];
nyan.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:nyan.size.height / 2];
nyan.physicsBody.dynamic = YES;
nyan.physicsBody.allowsRotation = NO;
...
nyan.physicsBody.categoryBitMask = nyanKategorie;
nyan.physicsBody.collisionBitMask = worldKategorie | tunnelKategorie;
nyan.physicsBody.contactTestBitMask = worldKategorie | tunnelKategorie;
...
WasserFallTexture1 = [SKTexture textureWithImageNamed:#"Wasserstrahl1.png"];
SKSpriteNode* tunnel1 = [SKSpriteNode spriteNodeWithTexture:WasserFallTexture1];
tunnel1.position = CGPointMake( 0, y );
tunnel1.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:tunnel1.size];
tunnel1.physicsBody.dynamic = NO;
tunnel1.physicsBody.categoryBitMask = tunnelKategorie;
tunnel1.physicsBody.contactTestBitMask = nyanKategorie;
...
[tunnel addChild:tunnel1];
I can do that without the nice engine of Spritekit. I implement it as well, but i want to know a way to do that with the SpriteKit engine.
I know that i can change the "SKPhysicsBody" type and areas, but i'm looking for a soloution witch can catch a collision between two png files non-transparent areas.
Thanks,
Sam
Sounds like actually seeing the physics bodies in action is what you need. There is a property on SKView called showsPhysics. Set that to YES and you can see the physics bodies of your sprites in action.
Related
I want objects of the same category to not bounce off or be moved when they collide with one another. I've tried playing around with collisionBitMask, contactTestBitMask, mass, density, etc. Does anyone know how to do this?
self.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:self.frame.size];
self.physicsBody.affectedByGravity = NO;
self.physicsBody.allowsRotation = NO;
self.physicsBody.categoryBitMask = CollisionTypeRock;
self.physicsBody.collisionBitMask = CollisionTypeRock;
self.physicsBody.contactTestBitMask = CollisionTypeRock;
Thanks.
I'm trying to move a sprite in a set direction on-screen, using the physicsBody.velocity property. However, the motion is quite "jumpy" (makes the game look like it's lagging). I assume this has something to do with the different time intervals between each call to the update-method. How could I achieve a more "smooth" motion?
Right now this is the code I have in my update-loop to make the sprite move forward:
if (_movingForward) {
CGFloat forwardVel = _ball.physicsBody.velocity.dx;
forwardVel += 20.0;
if (forwardVel > bMaxForwardVelocity) {
forwardVel = bMaxForwardVelocity;
}
_ball.physicsBody.velocity = CGVectorMake(forwardVel, _ball.physicsBody.velocity.dy);
}
As you can see, I'm trying to make the speed pick up, so it doesn't immediately reach it's terminal velocity. This is to make the motion look more natural. However, the lagging is ruining this effect greatly, even when the sprite supposedly is traveling at a set speed.
EDIT 1:
I'm trying to make a platform-style game (like Super Mario etc) where the _ball moves horizontally along the ground when the user taps the screen. The code for moving the ball to the right is included above the edit. The ground is made up of multiple tiles, each 32x32 and positioned right next to each other with no gap in-between.
As per request, here's the code for setting up the _balls physicsBody:
self.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:self.size.width/2.0];
self.physicsBody.dynamic = YES;
self.physicsBody.restitution = 0.5f;
self.physicsBody.usesPreciseCollisionDetection = YES;
self.physicsBody.allowsRotation = NO;
self.physicsBody.mass = 0.5f;
self.physicsBody.friction = 0.0f;
self.physicsBody.linearDamping = 0.0f;
self.physicsBody.categoryBitMask = CollisionCategoryBall;
And here's the code for the physicsBody of each individual tile:
tile.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:tile.size];
tile.physicsBody.dynamic = NO;
tile.physicsBody.categoryBitMask = CollisionCategoryGround;
The physicsWorld is set up like this:
self.physicsWorld.gravity = CGVectorMake(0, -4);
self.physicsWorld.contactDelegate = self;
Thanks!
EDIT 2:
This is a side-scrolling game, so the "camera" follows the ball. Here's the code for moving the background layer:
- (void)centerViewOn:(CGPoint)centerOn {
CGFloat x = Clamp(centerOn.x, (self.size.width / 2.0), (_bgLayer.layerSize.width) - (self.size.width / 2.0));
_worldNode.position = CGPointMake((int)-x, _worldNode.position.y);
}
The reason for the Clamp is so the "camera" doesn't scroll beyond the bounds of the background. This is when the ball is close to either the start or end of the level.
I'm casting the position to an int because without it, small gaps sometimes occur between the tiles. I was told this was because of some inaccuracy or something. However, even without casting the position to int, it's still a bitt "laggy". But because of the gaps between the tiles, it looks even worse.
The issue was with your scrolling code.
change this line :
_worldNode.position = CGPointMake((int)-x, _worldNode.position.y);
to
_worldNode.position = CGPointMake(-x, _worldNode.position.y);
The movement is then silky smooth.
But then you do get those seams. You should solve that in the placement of those tiles. You are likely positioning your _worldNode tiles with float values.
I have the following sprite that falls to the bottom of the screen:
// The View
self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];
self.physicsWorld.contactDelegate = self;
// The Sprite
SKSpriteNode *cube = [[SKSpriteNode alloc] initWithImageNamed:#"cube"];
[cube setPosition:CGPointMake(160,250);
[self addChild:cube];
// The Physics
cube.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:cube.frame.size];
cube.physicsBody.dynamic = YES;
cube.physicsBody.affectedByGravity = YES;
cube.physicsBody.mass = 0.02;
Is there a way to make it so its sides are bulging when it hits the bottom border of the screen? Something that would be Jelly like or a soft body that still maintains its shape to some extent but bulges out under its own weight? I hope this makes sense....
Visit the site https://gist.github.com/kazukitanaka0611/4b9d4ac9dff0cd317b6c it have explanation and source code for soft bodies (jelly) in sprite kit
quick and easy way without math:
1 use flash to tween your box warping.
2 export the tweened frames as a sprite sheet (texture atlas)
3 animate the texture atlas on contact with an edge physics body in your scene.
your box will fall and on contact animate the separate images to give the impression its warping/bulging sides.
i used this method and it works - in other words it gives the desired effect, which in my view is what is important - your gamers don't care how you did it, as long as it looks great.
Reanimating a bouncing ball in sprite-kit
I have a question about the best way to reanimate a bouncing ball. Using Ray Wenderlich's tutorial on building a break out game as a reference I have a number of circular shape nodes which continually bounce around a gravity-less environment. When the user touches one of them, it centers on the screen, stops moving, and transforms into something else. When the user touches it again, it is supposed to transform back into the circular shape node and then continue bouncing around the screen.
I have it all working as I like except for reanimating the ball. The manner in which I stop the animation is simply to set the physicsBody to nil. Once I want to reanimate, I call the method that sets up the physicsBody for the node and I apply an impulse to it. But frustratingly, the impulse does not have the effect I think it should. Clearly, my expectations are incorrect.
Here is the code in question:
- (void)applyPhysics
{
// Set physics properties
self.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:self.frame.size.width/2];
self.physicsBody.friction = 0.0f;
self.physicsBody.restitution = 1.0f;
self.physicsBody.linearDamping = 0.0f;
self.physicsBody.allowsRotation = NO;
self.physicsBody.collisionBitMask = wallCategory;
self.physicsBody.categoryBitMask = bubbleCategory;
}
- (void)morphPicker
{
BOOL check = NO;
if (check) NSLog(#"morphPicker called.");
[self runAction:[SKAction fadeAlphaTo:0.0 duration:.5]];
if (self.flipped) {
if (check) NSLog(#"The information side is showing.");
self.fillColor = bubbleColors[self.index % bubbleColors.count];
self.alpha = .9;
// Resume physics:
[self applyPhysics];
[self.physicsBody applyImpulse:CGVectorMake(10.0f, -10.0f)];
} else {
// stop physics:
self.physicsBody = nil;
if (check) NSLog(#"The statistic side is showing.");
self.fillColor = [SKColor blackColor];
self.alpha = .9;
[self transformToPickerNode];
[self removeAllChildren];
}
self.flipped = !self.flipped;
}
So my questions are these:
How should I be reanimating the ball if applying an impulse to it is not the correct method?
Is there a more elegant way to stop the animation after centering the node than setting the physicsBody to nil? Even to my novice instincts it feels like a brutish method.
After all my trials and searching for an answer to this I firmly believe that there is no elegant way to apply a new impulse to a sprite and expect it to move in the physics world. Thus my answer must be "it cannot be done at this point." However, my solution of removing all the the animated sprites from the scene and recreating them turned out to be the best solution for a completely different reason. The nature of my physics world caused my "floating bubbles" to eventually end up in the corners of the scene where they remained unmoving. Occasionally removing and recreating them had the effect of sending them happily bouncing around the scene again :)
I have an iOS game, and when a ball hits a target it explodes.
What would be the best way to animate this explosion?
If you're looking for something simple.
Make a series of images that animate the explosion. Add those to a UIImageView and start the animation. Something like this:
UIImage *image0 = [UIImage imageNamed:#"explosion0.png"];
UIImage *image1 = [UIImage imageNamed:#"explosion1.png"];
UIImage *image2 = [UIImage imageNamed:#"explosion2.png"];
UIImage *image3 = [UIImage imageNamed:#"explosion3.png"];
myImageView.animationImages = [NSArray arrayWithObjects:image0, image1, image2, image3, nil];
[myImageView setAnimationDuration:0.75f];
[myImageView startAnimation];
For a bouncing ball game, the Cocos2D game- and Box2d physics- (included with Cocos2D) engines are a great way to go.
Ray Wenderlich has three great tutorials on exactly what you want to do:
Intro to Box2D with Cocos2D Tutorial: Bouncing Balls
How To Create A Breakout Game with Box2D and Cocos2D Tutorial: Part 1
How To Create A Breakout Game with Box2D and Cocos2D Tutorial: Part 2
Once you get past the basics of working with Box2d objects, the key step is to create a Contact Listener (as described in the tutorials) which will tell you when you have a collision. Check (by iterating over contacts in your tick method) if the colliding objects are the ones you want for the explosion, and if so add them to a vector of objects to be destroyed (we can't do this while iterating over contacts or we will invalidate the iterator). Remember the coordinates of the collision and set a flag for explosion.
After exiting the loop destroy the bodies and run the explosion effect at the saved position.
Cocos2D has some very nice built-in explosion effects, and the one I am using for my project is CCParticleSun. You can find some screenshots of someone using this effect here. (The curiously named CCParticleExplosion just gave a lot of confetti flying around the screen.)
Here is the relevant portion from some preliminary code I have working, which is mostly from the tutorial. You will still need to do everything else, eg. create and set up your world and bodies in your init method, update positions, apply forces, and draw in your tick method, implement your Contact Listener class, etc. For all this refer to the tutorials.
std::vector<b2Body *>toDestroy;
std::vector<MyContact>::iterator pos;
CGPoint p;
bool explode = FALSE;
for(pos = _contactListener->_contacts.begin();
pos != _contactListener->_contacts.end(); ++pos) {
MyContact contact = *pos;
if ((contact.fixtureA->GetBody() == _moonBody && contact.fixtureB->GetBody() == _moon2Body) ||
(contact.fixtureA->GetBody() == _moon2Body && contact.fixtureB->GetBody() == _moonBody)) {
NSLog(#"Moons collided!");
explode = TRUE;
p = CGPointMake(PTM_RATIO*(_moonBody->GetPosition().x + _moon2Body->GetPosition().x)/2.,PTM_RATIO*(_moonBody->GetPosition().y + _moon2Body->GetPosition().y)/2.);
if (std::find(toDestroy.begin(), toDestroy.end(), _moonBody) == toDestroy.end()) {
toDestroy.push_back(_moonBody);
}
if (std::find(toDestroy.begin(), toDestroy.end(), _moon2Body) == toDestroy.end()) {
toDestroy.push_back(_moon2Body);
}
}
}
std::vector<b2Body *>::iterator pos2;
for(pos2 = toDestroy.begin(); pos2 != toDestroy.end(); ++pos2) {
b2Body *body = *pos2;
if (body->GetUserData() != NULL) {
CCSprite *sprite = (CCSprite *) body->GetUserData();
[sprite.parent removeChild:sprite cleanup:YES]; }
world->DestroyBody(body);
}
if (explode)
{
explosion = [[CCParticleSun alloc]initWithTotalParticles:250];
explosion.texture = [[CCTextureCache sharedTextureCache] addImage:#"fire.png"];
explosion.autoRemoveOnFinish = YES;
explosion.startSize = 15.0f;
explosion.speed = 30.0f;
explosion.position = p;
explosion.duration = 1.0f;
[self addChild:explosion z:self.zOrder+1];
}
What you want, then, is a way to create a particle emission system. My suggestion is to use a CAEmitterLayer. Ray Wenderlich has a great tutorial: UIKit Particle Systems in iOS 5 Tutorial
iPhone Programming Tutorial: Animating a Game Sprite
If you need to make an explosion another alternative would to use Cocos2d and do:
CCParticleSun *anExplosion=[CCParticleGalaxy node];
[kk setPosition:ball.position];
[self addChild:anExplosion];
Not really an animation, also, from the question you don't seem to be using Cocos2d, but if you start using it you can do this...