i have car body and 2 tiers as seprate images .
how to fix as car body(box2d with cocos2d-x) and moving animation.(i need to rotate tier) and jumping etc.,?
in normal cocos2d-x i can make something like this..
car = CCSprite::spriteWithFile("car.png");
car->setPosition(ccp(car->getContentSize().width/2+30, car->getContentSize().height-19));
this->addChild(car, 10);
tire = CCSprite::spriteWithFile("tire.png");
tire->setPosition(ccp(tire->getContentSize().width/2+43, tire->getContentSize().height+8));
this->addChild(tire, 10);
tire1 = CCSprite::spriteWithFile("tire.png");
tire1->setPosition(ccp(tire->getContentSize().width/2+136, tire->getContentSize().height+8));
this->addChild(tire1, 10);
CCRotateBy *Rot = CCRotateBy::actionWithDuration (1.0f, 360);
CCRepeatForever *rep = CCRepeatForever::actionWithAction(Rot);
CCRotateBy *Rot1 = CCRotateBy::actionWithDuration(1.0f, 360);
CCRepeatForever *rep1 = CCRepeatForever::actionWithAction(Rot1);
tire->runAction(rep);
tire1->runAction(rep1);
but in box2d how to make? any example..
for collison detction for all thing planing to use box2d.
cocos2D-x Doc contains an article about Box2D..
http://www.cocos2d-x.org/docs/manual/framework/native/physics/physics-integration/en
not that detailed, but good enough to start with.
Also cocos2D-x framework test contains example of both Box2D and Chipmumk physics example.
http://www.cocos2d-x.org/docs/manual/framework/native/getting-started/v3.0/how-to-run-cpp-tests-on-win32/en
Related
I am building a game with Xcode's spritekit. Its a platform game and right now it functions well with flat ground pieces. I was wondering if it was possible to ignore transparency in the png for collisions. That is to say, If i have a ground piece with a curved floor and transparency filling the troughs, can i make the player walk the curves instead of a square bounding box covering the whole thing? The only example i can find is in the Gamemaker GML language, you can do "precise" collisions such that blank space in the images do not count as part of the sprite. I can supply code if necessary but this seems like more of a conceptual question. Thanks in advance
Hey there's a easy solution for this provided in the Apple Documentation.
SKSpriteNode *sprite = [SKSpriteNode spriteNodeWithImageNamed:#"Spaceship"];
sprite.physicsBody = [SKPhysicsBody bodyWithTexture:sprite.texture size:sprite.texture.size];
This creates a physics body around the physical paths of the texture.
Simulating Physics - SpriteKit Programming Guide
It's all in how you instantiate the physicsBody of the node in question.
node.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:node.size];
is probably the easiest and most common way of making a physicsBody, but will also create the issue you've identified above, because, for all collision purposes, the node is a rectangle.
take a look at the documentation for SKPhysicsBody to see the other options available to you. PolygonFromPath and BodyWithBodies are probably the best suited for what you're doing.
SKPhysicsBody is the right move, just wanted to note that it does make sense to have a separate (simplified) mask-image for SKPhysicsBody to improve your performance, simplified from color and geometry standpoint, and here's the code:
let birdMask: UInt32 = 0x1 << 0
let pipeMask: UInt32 = 0x1 << 1
//...
pipeImage = SKSpriteNode(imageNamed: "realImage")
//... size and position
let maskTexture = SKSpriteNode(imageNamed: mask)
maskTexture.size = pipeImage!.size // size of texture w/ real imageNamed
pipeImage!.physicsBody?.usesPreciseCollisionDetection = true
pipeImage!.physicsBody = SKPhysicsBody(texture: maskTexture.texture!, size: size)
pipeImage!.physicsBody?.affectedByGravity = false // disable falling down...
pipeImage!.physicsBody?.allowsRotation = false
pipeImage!.physicsBody?.isDynamic = true
pipeImage!.physicsBody?.friction = 0
pipeImage!.physicsBody?.categoryBitMask = pipeMask
pipeImage!.physicsBody?.collisionBitMask = birdMask | pipeMask
pipeImage!.physicsBody?.contactTestBitMask = birdMask | pipeMask
and more detailed example/guide.
I'm fiddling around with cocos2d v3 in combination with sprite builder.
The game is a simple catch and avoid game, objects coming down an the hero is standing in the bottom of the screen and you can move him around with the accelerometer.
I have a level file (cclayer) with some objects (ccnode) in it, the have physics enabled.
In my update function I move the layer slowly down.
If the objects have physics enabled, they just drop down. If I switch it to statics physics, they stay in place.
The only way I can find to move the object along with the layer is to turn off the physics completely. But then the collisions won't work anymore...
This kept me buys for the past 4 hours or so.
What is the best approach for this situation?
Thanks in advance guys!
this is my update function:
- (void)update:(CCTime)delta {
float maxX = winSize.width - _hero.contentSize.width/2;
float minX = _hero.contentSize.width/2;
CMAccelerometerData *accelerometerData = _motionManager.accelerometerData;
CMAcceleration acceleration = accelerometerData.acceleration;
CGFloat newXPosition = _hero.position.x + acceleration.x * 1000 * delta;
newXPosition = clampf(newXPosition, minX, maxX);
_hero.position = CGPointMake(newXPosition, _hero.position.y);
//level position
CGPoint oldLayerPosition = _levelNode.position;
float xNew = oldLayerPosition.x;
float yNew = oldLayerPosition.y -1.4f;
_levelNode.position = ccp(xNew, yNew);
}
This is a design decision made within the physics engine. Physics bodies do not move with their parents. See: https://github.com/cocos2d/cocos2d-iphone/issues/570
You need to change the design of your game so that your hero moves, and the obstacles stay in the same position. Then you implement a camera like mechanism to follow your moving hero.
We have used the same approach in our flappy bird tutorial.
i want to create path projection like angry birds.
When i throw my ball i want to show projection on ball that on this path my ball has thrown.
I have seen a post on stackoverflow and i have implemented it .
if(trailtimer % 2 == 0 && isFired)
{
CCSprite * dot_Sprite = [[CCSprite alloc] initWithFile:#"whitedot.png"];
dot_Sprite.position = ccp(b->GetPosition().x * PTM_RATIO,b->GetPosition().y * PTM_RATIO);
dot_Sprite.scale = 0.1;
[self addChild:dot_Sprite z:2 tag:111];
}
}
In this code its working fine . but adding multiple sprites will slow my game.
Is there anyother option/way to implement path projection in my game.
You could try to create the dot like this:
CCSprite * dot_Sprite = [[CCSprite spriteWithFile:#"whitedot.png"];
and see if it helps.
This will add the dot to the auto release pool and make sure memory is free after usage
I see everyone saying that you add gravity like so in a Box2D world:
b2Vec2 gravity = b2Vec2(0.0f, -10.0f);
bool doSleep = false;
world = new b2World(gravity, doSleep);
The thing is though, what if I want gravity only on a specific b2Body which contains userData from a CCSprite? AFAIK this will apply gravity to everything in the world which I do not want, so can someone explain to me how I can apply this gravity only to a specific b2Body?
Thanks!
Edit1:
Can I just do this line,
_bottomBody->ApplyForce(gravity, _bottomBody->GetPosition());
Instead of the world = new b2World... etc... Wouldn't that work with gravity only on that b2Body?
Just apply a force/impulse to the specific b2Body every frame. It will emulate gravity.
// a procedure called every frame
void Application::on_update_world(double t)
{
m_body_with_custom_gravity->applyForce(CUSTOM_GRAVITY * m_body_with_custom_gravity->getMass());
m_phys_world->Step(t, VEL_ITERATIONS, POS_ITERATIONS);
}
A thread with a question closely related to your:
How to apply constant force on a Box2D body?
So I have a XNA application set up. The camera is in first person mode, and the user can move around using the keyboard and reposition the camera target with the mouse. I have been able to load 3D models fine, and they appear on screen no problem. Whenever I try to draw any primitive (textured or not), it does not show up anywhere on the screen, no matter how I position the camera.
In Initialize(), I have:
quad = new Quad(Vector3.Zero, Vector3.UnitZ, Vector3.Up, 2, 2);
quadVertexDecl = new VertexDeclaration(this.GraphicsDevice, VertexPositionNormalTexture.VertexElements);
In LoadContent(), I have:
quadTexture = Content.Load<Texture2D>(#"Textures\brickWall");
quadEffect = new BasicEffect(this.GraphicsDevice, null);
quadEffect.AmbientLightColor = new Vector3(0.8f, 0.8f, 0.8f);
quadEffect.LightingEnabled = true;
quadEffect.World = Matrix.Identity;
quadEffect.View = Matrix.CreateLookAt(cameraPosition, cameraTarget, Vector3.Up);
quadEffect.Projection = this.Projection;
quadEffect.TextureEnabled = true;
quadEffect.Texture = quadTexture;
And in Draw() I have:
this.GraphicsDevice.VertexDeclaration = quadVertexDecl;
quadEffect.Begin();
foreach (EffectPass pass in quadEffect.CurrentTechnique.Passes)
{
pass.Begin();
GraphicsDevice.DrawUserIndexedPrimitives<VertexPositionNormalTexture>(
PrimitiveType.TriangleList,
quad.Vertices, 0, 4,
quad.Indexes, 0, 2);
pass.End();
}
quadEffect.End();
I think I'm doing something wrong in the quadEffect properties, but I'm not quite sure what.
I can't run this code on the computer here at work as I don't have game studio installed. But for reference, check out the 3D audio sample on the creator's club website. They have a "QuadDrawer" in that project which demonstrates how to draw a textured quad in any position in the world. It's a pretty nice solution for what it seems you want to do :-)
http://creators.xna.com/en-US/sample/3daudio