如何使用帧网格系统防止相机运动更新

Question

我试图引入一个Aframe系统，通过在场景上覆盖网格来防止相机移动到场景的某些部分，并防止移动到标记为满的网格单元中。

现在我只检查一个维度(z轴(，以确定相机是否在球体附近。当前代码将相机移回最后一个允许的位置，当相机被检测到在网格的一个单元格中时，它不应该是。

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)
}
})

场景标记

<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，如果运动会将相机放置在不允许的单元格中，我希望防止初始相机更改位置。

当一个特定的现有组件(在这种情况下是相机(的属性更新时，应该如何引入一个函数来调用？

Answer 1

在勾选方法中检查无效的相机位置，并在满足条件时禁用相机移动源。所提供示例中的wasd控件和look控件。