Can't get collisions to work?!

[fiverivers]

// Initialize Phaser, and creates a 400x490px gamevar game = new Phaser.Game(400, 490, Phaser.AUTO, 'game_div');// Creates a new 'main' state that wil contain the gamevar main_state = {    preload: function() { // Function called first to load all the assets                // Change the background color of the game        this.game.stage.backgroundColor = '#71c5cf';                // Load the bird sprite        this.game.load.image('bird', 'assets/bird.png');                // Load the pipe sprite        this.game.load.image('pipe', 'assets/pipe.png');      },    create: function() {             game.physics.startSystem(Phaser.Physics.ARCADE);    // Fuction called after 'preload' to setup the game                // Display the bird on the screen    this.bird = this.game.add.sprite(100, 245, 'bird');    // Add gravity to the bird to make it fall   this.bird.body.gravity.y = 1000;            // Call the 'jump' function when the spacekey is hit    var space_key =     this.game.input.keyboard.addKey(Phaser.Keyboard.SPACEBAR);    space_key.onDown.add(this.jump, this);            // Create multiple pipes    this.pipes = game.add.group();     this.pipes.createMultiple(20, 'pipe');     this.pipes.enableBody = true;        // Timer and adds rows of pipes    this.timer = this.game.time.events.loop(1500,       this.add_row_of_pipes, this);        // Adding key values.    upKey = game.input.keyboard.addKey(Phaser.Keyboard.UP);    downKey = game.input.keyboard.addKey(Phaser.Keyboard.DOWN);    leftKey = game.input.keyboard.addKey(Phaser.Keyboard.LEFT);    rightKey = game.input.keyboard.addKey(Phaser.Keyboard.RIGHT);    this.bird.body.collideWorldBounds = true;            this.score = 0;      var style = { font: "30px Arial", fill: "#ffffff" };      this.label_score = this.game.add.text(20, 20, "0", style);          game.physics.arcade.enable(this.bird);    },        update: function() {            // Function called 60 times per second                // If the bird is out of the world (too high or too low), call the 'restart_game' function//        if (this.bird.inWorld   == false)//            this.restart_game();                        if (leftKey.isDown)        {            this.bird.body.velocity.x = -350        }        else if (rightKey.isDown)        {            this.bird.body.velocity.x = 350        }                 game.physics.arcade.collide(this.bird, this.pipes);    },        // Make the bird jump     jump: function() {          // Add a vertical velocity to the bird        this.bird.body.velocity.y = -350;},    // Restart the game    restart_game: function() {          // Start the 'main' state, which restarts the game        this.game.state.start('main');        this.game.time.events.remove(this.timer);},        add_one_pipe: function(x, y) {          // Get the first dead pipe of our group        var pipe = this.pipes.getFirstDead();        // Set the new position of the pipe        pipe.reset(x, y);        // Add velocity to the pipe to make it move left        pipe.body.velocity.y = -200;         // Kill the pipe when it's no longer visible         pipe.outOfBoundsKill = true;    },        add_row_of_pipes: function() {          var hole = Math.floor(Math.random()*5)+1;//        for (var i = 0; i < 8; i++)//            if (i != hole && i != hole +1) //                this.add_one_pipe(400, i*60+10);                        for (var i = 0; i < 8; i++)            if (i != hole && i != hole +1)                 this.add_one_pipe(i*60+10, 500);                 this.score += 1;          this.label_score.content = this.score;      },};// Add and start the 'main' state to start the gamegame.state.add('main', main_state);  game.state.start('main'); 

I can't figure out for the life of me why this won't work I get an error saying gravity is null...

[ragnarok]

Try to add  "this.game.physics.enable(bird, Phaser.Physics.ARCADE)" before modifying body-variables.

 

I think bird has no body before this, so using "this.bird.body.gravity" is doomed to fail.

[fiverivers]

Try to add  "this.game.physics.enable(bird, Phaser.Physics.ARCADE)" before modifying body-variables.

 

I think bird has no body before this, so using "this.bird.body.gravity" is doomed to fail.

 

Thanks for that! Through adding that code to the bird and pipes both have collision however..... after 3 pipes spawn the entire code crashes and I get an error saying cannot read property of 'reset' null.

add_one_pipe: function(x, y) {          // Get the first dead pipe of our group        var pipe = this.pipes.getFirstDead();        // Set the new position of the pipe        pipe.reset(x, y);        // Add velocity to the pipe to make it move left        pipe.body.velocity.y = -200;         // Kill the pipe when it's no longer visible         pipe.outOfBoundsKill = true;    },

In this function the x and y parameters are null for some reason, any ideas?