如何使用镜框网格系统防止相机运动更新

Question

[我正在尝试引入一种Aframe系统，该系统通过在场景上覆盖网格并防止运动到标记为已满的网格单元中来防止摄像机移动到场景的某些部分。

目前，我仅检查一个维度（z轴）以了解相机是否在球体附近。当检测到摄像头位于不应该存在的网格单元中时，当前代码会将摄像头移回最后允许的位置。

组件，系统注册

AFRAME.registerSystem('gridsystem', {
    init: function () {
        // start with 1d

        this.grid = Array(20).fill(0)
        // set the sphere at 5
        this.grid[5] = 1
        this.camera = {}
        // stop motion a quarter of a grid from a boundary
        this.boundarydist = 2
    },
    registerCam: function (el) {
        let v = new THREE.Vector3()
        console.log(el)
        this.camera.e = el
        console.log(el.object3D.position)
        el.object3D.getWorldPosition(v)
        this.camera.v = v
        this.lastpermitted = this.camera.v.z
    },
    // abstract this into multiple dimensions later
    checkPosition: function () {
        // 
        // find position that the camera is in
        // convert z position 
        // need to make it possible to handle positive and negative
        let z = this.camera.e.object3D.position.z
        for (let sign of [-1, 1]) {
            let index = Math.floor(z + sign * this.boundarydist)
            if (this.grid[index] == 1) {
                // we proceeded into a grid we shouldn't be
                console.log("bumped into")
                this.camera.e.object3D.position.z = this.lastpermitted
                return
            }

        }
        this.lastpermitted = this.camera.e.object3D.position.z



    }

})

AFRAME.registerComponent("gridsystem", {
    init: function () {
        this.system.registerCam(this.el)
        setInterval(() => {
            this.system.checkPosition()
        }, 100)
    }
})

场景降价

<a-scene>
  <a-entity
    id="sphere"
    geometry="primitive: sphere"
    material="color: tomato; shader: flat"
    position="0 0.15 5"
    light="type: point; intensity: 5"
    />
    <a-entity id="camera" camera  wasd-controls gridsystem look-controls />
</a-scene>

问题

相反，如果该运动会将摄像机放置在不允许的单元格中，那么我想防止发生初始摄像机更改位置的情况。

当特定的现有组件（在这种情况下为相机）的属性更新时，如何引入一个函数来调用？

Answer 1

检查tick method中的无效摄像机位置，并在满足条件时禁用摄像机移动的源。在提供的示例中为wasd-controls和look-controls。