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第一人称移动

此应用实现第一人称角色移动。

这个控制器对场景配置有要求：角色除了挂载脚本外，还必须具有刚体和碰撞组件。脚本还支持将相机实体作为 Player 的子级，并在检查器中手动指定；如果没有相机实体，脚本会创建一个。

完整场景配置见教程项目。

下面的脚本实现以下功能：

  • 监听鼠标和键盘输入。
  • 根据鼠标输入更新相机实体。
  • 施加力，使玩家实体在场景中移动。

注意，脚本从不直接设置玩家速度，而是通过刚体 API 的 applyForce 函数施力来移动玩家。

我们还在编辑器检查器中为刚体组件设置了以下属性：

  • 应用线性阻尼以限制最大速度，并防止玩家松开输入按键后继续滑行。
  • 将所有轴上的 Angular Factor（角运动因子）降为 0，防止玩家翻倒。

刚体属性

var FirstPersonMovement = pc.createScript('firstPersonMovement');

FirstPersonMovement.attributes.add('camera', {
    type: 'entity',
    description: 'Optional, assign a camera entity, otherwise one is created'
});

FirstPersonMovement.attributes.add('power', {
    type: 'number',
    default: 2500,
    description: 'Adjusts the speed of player movement'
});

FirstPersonMovement.attributes.add('lookSpeed', {
    type: 'number',
    default: 0.25,
    description: 'Adjusts the sensitivity of looking'
});

// initialize code called once per entity
FirstPersonMovement.prototype.initialize = function() {
    this.force = new pc.Vec3();
    this.eulers = new pc.Vec3();

    var app = this.app;

    // Listen for mouse move events
    app.mouse.on("mousemove", this._onMouseMove, this);

    // when the mouse is clicked hide the cursor
    app.mouse.on("mousedown", function () {
        app.mouse.enablePointerLock();
    }, this);

    // Check for required components
    if (!this.entity.collision) {
        console.error("First Person Movement script needs to have a 'collision' component");
    }

    if (!this.entity.rigidbody || this.entity.rigidbody.type !== pc.BODYTYPE_DYNAMIC) {
        console.error("First Person Movement script needs to have a DYNAMIC 'rigidbody' component");
    }
};

// update code called every frame
FirstPersonMovement.prototype.update = function(dt) {
    // If a camera isn't assigned from the Editor, create one
    if (!this.camera) {
        this._createCamera();
    }

    var force = this.force;
    var app = this.app;

    // Get camera directions to determine movement directions
    var forward = this.camera.forward;
    var right = this.camera.right;


    // movement
    var x = 0;
    var z = 0;

    // Use W-A-S-D keys to move player
    // Check for key presses
    if (app.keyboard.isPressed(pc.KEY_A) || app.keyboard.isPressed(pc.KEY_Q)) {
        x -= right.x;
        z -= right.z;
    }

    if (app.keyboard.isPressed(pc.KEY_D)) {
        x += right.x;
        z += right.z;
    }

    if (app.keyboard.isPressed(pc.KEY_W)) {
        x += forward.x;
        z += forward.z;
    }

    if (app.keyboard.isPressed(pc.KEY_S)) {
        x -= forward.x;
        z -= forward.z;
    }

    // use direction from keypresses to apply a force to the character
    if (x !== 0 || z !== 0) {
        force.set(x, 0, z).normalize().scale(this.power);
        this.entity.rigidbody.applyForce(force);
    }

    // update camera angle from mouse events
    this.camera.setLocalEulerAngles(this.eulers.y, this.eulers.x, 0);
};

FirstPersonMovement.prototype._onMouseMove = function (e) {
    // If pointer is disabled
    // If the left mouse button is down update the camera from mouse movement
    if (pc.Mouse.isPointerLocked() || e.buttons[0]) {
        this.eulers.x -= this.lookSpeed * e.dx;
        this.eulers.y -= this.lookSpeed * e.dy;
    }
};

FirstPersonMovement.prototype._createCamera = function () {
    // If user hasn't assigned a camera, create a new one
    this.camera = new pc.Entity();
    this.camera.setName("First Person Camera");
    this.camera.addComponent("camera");
    this.entity.addChild(this.camera);
    this.camera.translateLocal(0, 0.5, 0);
};