Phaser 3：初始重力设0后玩家无法跳跃的解决方法

问题根源 #

1. Update函数未正确暴露：你的update函数嵌套在create函数内部，Phaser无法全局调用它，导致键盘输入逻辑完全不执行。
2. 未初始化键盘输入对象：没有创建cursors对象来检测方向键按下状态，跳跃判断条件永远不成立。
3. 修改配置文件重力无效：config仅用于初始化游戏，运行时修改config.physics.arcade.gravity不会影响当前物理世界的状态。

修复步骤 #

1. 将update函数移到create函数外部，与preload、create同级，确保Phaser能正确调用。
2. 在create函数中初始化键盘输入对象：cursors = this.input.keyboard.createCursorKeys();。
3. 给玩家精灵单独设置重力（而非全局重力），避免影响其他物理体：
   • 初始时设置玩家重力为0，防止下落；
   • 跳跃时设置玩家重力为300，使其能下落；
   • 玩家落地后重置重力为0，保持静止。

修改后的完整代码 #

let config = {
    type: Phaser.AUTO,
    width: 800,
    height: 500,
    physics: {
        default: 'arcade',
        arcade: {
            gravity: { y: 0 },
            debug: false
        }
    },
    scene: {
        preload: preload,
        create: create,
        update: update
    },
    scale: {
        mode: Phaser.Scale.FIT,
        parent: 'root',
        autoCenter: Phaser.Scale.CENTER_BOTH,
        width: 800,
        height: 600
    },
};

new Phaser.Game(config)

function preload() {
    this.load.image('sky', require('../assets/backgrounds/sky.png'));
    this.load.image('jungle', require('../assets/backgrounds/jungle.png'));
    
    this.load.image('ground', require('../assets/tiles/ground-transp.png'))
    this.load.image('small-platform', require("../assets/tiles/small-platform-removebg-preview.png"))
    this.load.image('jungle-platform', require("../assets/tiles/jungle-platform.png"))
    this.load.image('large-platform', require("../assets/tiles/large-platform-removebg-preview.png"))
    this.load.image('tree', require("../assets/backgrounds/treetrunk.png"))
    this.load.image('plant', require("../assets/backgrounds/plant.png"))
    this.load.image('plant2', require("../assets/backgrounds/plants2.png"))
    this.load.image('rock', require("../assets/backgrounds/rock.png"))

    this.load.atlas('sacred', require('../assets/spritesheets/sacredRock.png'), require('../assets/spritesheets/sacredRock.json'))
    this.load.atlas('player', require('../assets/spritesheets/dilopodon.png'), require('../assets/spritesheets/dilopodon.json'))

    this.load.tilemapTiledJSON('Ground', require('../assets/maps/simple-tutorial.json'));
}

function create () {
    this.bg = this.add.image(-41, -41, 'sky');
    this.bg = this.add.image('jungle');
    this.add.image(67, 370, 'tree')
    this.add.image(167, 429, 'plant')
    this.add.image(700, 405, 'plant2')
    this.add.image(300, 440, 'rock')
    
    const map = this.make.tilemap({ key: 'Ground' })
    
    // 创建 tilesets
    const groundTileSet = map.addTilesetImage('Ground', 'ground')
    const platformTileset = map.addTilesetImage('small-platform', 'small-platform')
    const junglePlatformTileset = map.addTilesetImage('jungle-platform', 'jungle-platform')
    const largePlatformTileset = map.addTilesetImage('large-platform', 'large-platform')
    
    let groundLayer = map.createLayer('Ground', [groundTileSet, platformTileset, junglePlatformTileset, largePlatformTileset])
    groundLayer.setCollisionByExclusion([-1]);
    
    // 创建玩家
    player = this.physics.add.sprite(100, 420, 'player')
    player.setBounce(0.2);
    player.setCollideWorldBounds(true)
    player.setGravityY(0); // 初始玩家重力为0，防止下落

    player.body.width = 60
    player.body.height = 60
    player.body.offset.x = 10
    player.body.offset.x = 10

    // 创建圣石
    sacredStone = this.physics.add.sprite(400, 270, 'sacred')
    sacredStone.setCollideWorldBounds(true)
    sacredStone.setGravityY(0); // 固定圣石，不受重力影响

    sacredStone.body.width = 60
    sacredStone.body.height = 230

    // 物理碰撞
    this.physics.add.collider(groundLayer, player )
    this.physics.add.collider(groundLayer, sacredStone )

    // 初始化键盘输入
    cursors = this.input.keyboard.createCursorKeys();
}

function update() {
    sacredStone.anims.play('glow', true)

    if (cursors.left.isDown) {
        player.setVelocityX(-160);
        player.anims.play('walkLeft', true);
    } else if (cursors.right.isDown) {
        player.setVelocityX(160);
        player.anims.play('walkRight', true);
    } else {
        player.setVelocityX(0);
        player.anims.play('idle', true);
    }

    // 跳跃逻辑
    if (cursors.up.isDown && player.body.blocked.down) {   
        player.setGravityY(300); // 设置玩家重力，使其下落
        player.setVelocityY(-330);
    }

    // 玩家落地后重置重力为0，保持静止
    if (player.body.blocked.down) {
        player.setGravityY(0);
    }
}

额外说明 #

• 如果需要全局重力生效，可改用this.physics.world.gravity.y = 300修改全局重力，但需给不需要下落的物体（如圣石）单独设置setGravityY(0)。
• 确保你的动画（如walkLeft、glow）已正确定义，否则会出现报错。

内容的提问来源于stack exchange，提问作者Jordan