Html 防止摄像头移动'；通过'；帧对象
假设我有一个圆柱体模型，我将其加载到我的webvr场景中。如何使对象成为实体？也就是说，用户（摄像机视图）不能在对象内占据任何位置或“穿过”对象。我怎样才能做到这一点Html 防止摄像头移动'；通过'；帧对象,html,three.js,aframe,webvr,Html,Three.js,Aframe,Webvr,假设我有一个圆柱体模型，我将其加载到我的webvr场景中。如何使对象成为实体？也就是说，用户（摄像机视图）不能在对象内占据任何位置或“穿过”对象。我怎样才能做到这一点 <a-scene> <a-assets> <a-asset-item id="cube-obj" src="cube.obj"></a-asset-item> </a-assets> <a-entity id="cameraWrapper" po
<a-scene>
<a-assets>
<a-asset-item id="cube-obj" src="cube.obj"></a-asset-item>
</a-assets>
<a-entity id="cameraWrapper" position="0 2 10" rotation="0 0 0">
<a-camera near="0.1" user-height="0" id="camera" listener></a-camera>
</a-entity>
<a-entity obj-model="obj: #cube-obj; mtl: #cube-mtl" scale="1 1 1" rotation="-90 0 0"></a-entity>
<a-plane position="0 4 4" rotation="-90 0 -90" width="4" height="4" color="#7BC8A4"></a-plane>
<a-sky color="#ECECEC"></a-sky>
</a-scene>
这取决于您计划支持哪些设备，以及您如何允许用户支持这些设备 在场景中导航。对于大多数虚拟现实体验，请遵循最佳实践，仅限 根据用户的运动按比例移动相机。如果用户 在roomscale空间中向前移动，相机被“阻挡”，这是一个非常糟糕的问题 经验对于大多数VR应用程序，最好使用 , 设计场景以避开障碍物，或探索更具创意的场景 在世界各地移动用户的方式 用于使用gamepad或WASD控件的非VR桌面体验，或用于VR场景 如果摄像头位于车辆内部，则可以添加 到 防止通过障碍物移动
^我会尽快将其添加到A-Frame常见问题解答或文档中。这已被添加到。这里有一个，还有一个。自从我来到这里寻找一个更简单的答案（不是处理自定义对象，而是标准的AFrame对象）以来，也许这不是您想要的。但是如果你只是要求“防止相机穿过一帧物体”，也许这会对你有所帮助 在下面的示例中，我使用管理物理。 我从中复制了名为kinema body（请参见嵌入脚本）的
运动学bodykinema主体静态主体kinema bodystatic body
/**
*Kinema身体。
*
*基于运动学体，从帧附加（现在，基本上是一个副本，
*只是因为我读到它在一个框架中被弃用）
*
* https://github.com/donmccurdy/aframe-extras/blob/master/src/misc/kinematic-body.js
*
*托管动态实体，可移动但不受
*物理引擎。这不是一个真正的运动学体，从我们的意义上说
*让物理引擎有选择地计算与它的碰撞
*将这些碰撞应用于对象。物理引擎无法决定
*元素的位置/速度/旋转。
*
*用于摄影机对象，因为完整的物理模拟将创建
*对玩家来说感觉不自然的动作。两足动物的运动不需要
*很好地转化为刚体物理。
*
*见：http://www.learn-cocos2d.com/2013/08/physics-engine-platformer-terrible-idea/
*以及：http://oxleygamedev.blogspot.com/2011/04/player-physics-part-2.html
*/
常数EPS=0.000001；
AFRAME.registerComponent（'kinema-body'{
依赖项：['velocity']，
/*******************************************************************
*模式
*/
模式：{
质量：{默认值：5}，
半径：{默认值：1.3}，
linearDamping:{默认值：0.05}，
enableSlopes:{default:true}，
enableJumps:{default:false}，
},
/*******************************************************************
*生命周期
*/
init：函数（）{
this.system=this.el.sceneEl.systems.physics；
this.system.addComponent（this）；
const el=this.el，
data=this.data，
position=（new CANNON.Vec3（））.copy（el.object3D.getWorldPosition（new THREE.Vector3（））；
this.body=新的CANNON.body({
材质：this.system.getMaterial（'staticMaterial'），
职位:职位,，
mass:data.mass，
linearDamping:data.linearDamping，
固定旋转：正确
});
这个。body。addShape(
新加农炮。球体（数据。半径），
新加农炮.Vec3（0，data.radius，0）
);
this.body.el=this.el；
this.el.body=this.body；
this.system.addBody（this.body）；
if（el.hasAttribute（'wasd-controls'））{
控制台。警告（“[kinema body]与wasd控件不兼容，请使用移动控件”）；
}
},
删除：函数（）{
this.system.removeBody（this.body）；
this.system.removeComponent（this）；
删除此.el.正文；
},
/*******************************************************************
*更新
*/
/**
*检查CANNON.World是否存在碰撞并尝试将其应用于
*元素自动，以玩家友好的方式。
*
*对于水平表面，这里有额外的逻辑。基本要求：
*（1）仅在不接触任何水平面时施加重力。
*（2）移动时，将速度正好投射到一个地面上。
*如果与两个地面（例如地面+坡道）接触，选择
*与流速发生碰撞的那个，如果有的话。
*/
beforeStep：函数（t，dt）{
如果（！dt）返回；
const el=this.el；
const data=this.data
const body=this.body；
如果（！data.enableJumps）body.velocity.set（0,0,0）；
body.position.copy（el.getAttribute（'position'））；
},
步骤：（函数（）{
常数速度=新的3.Vector3（），
normalizedVelocity=new THREE.Vector3（），
currentSurfaceNormal=new THREE.Vector3（），
groundNormal=新的3.Vector3（）；
返回函数（t，dt）{
如果（！dt）返回；
让body=this.body，
data=this.data，
didclide=false，
高度，地面高度=-无穷大，
地体，
contacts=this.system.getContacts（）；
dt=Math.min（dt，this.system.data.maxInterval*1000）；
groundNormal.set（0,0,0）；
velocity.copy（this.el.getAttribute
<!DOCTYPE html>
<html>
<head>
<script src="//aframe.io/releases/0.8.2/aframe.min.js"></script>
<script src="//cdn.rawgit.com/donmccurdy/aframe-extras/v5.0.0/dist/aframe-extras.min.js"></script>
<script src="//cdn.rawgit.com/donmccurdy/aframe-physics-system/v3.3.0/dist/aframe-physics-system.min.js"></script>
<script>
/**
* Kinema body.
*
* Based on kinematic-body, from AFrame Extras (for now, basically a copy,
* just because I read it is deprecated in AFrame Extras)
*
* https://github.com/donmccurdy/aframe-extras/blob/master/src/misc/kinematic-body.js
*
* Managed dynamic body, which moves but is not affected (directly) by the
* physics engine. This is not a true kinematic body, in the sense that we are
* letting the physics engine _compute_ collisions against it and selectively
* applying those collisions to the object. The physics engine does not decide
* the position/velocity/rotation of the element.
*
* Used for the camera object, because full physics simulation would create
* movement that feels unnatural to the player. Bipedal movement does not
* translate nicely to rigid body physics.
*
* See: http://www.learn-cocos2d.com/2013/08/physics-engine-platformer-terrible-idea/
* And: http://oxleygamedev.blogspot.com/2011/04/player-physics-part-2.html
*/
const EPS = 0.000001;
AFRAME.registerComponent('kinema-body', {
dependencies: ['velocity'],
/*******************************************************************
* Schema
*/
schema: {
mass: { default: 5 },
radius: { default: 1.3 },
linearDamping: { default: 0.05 },
enableSlopes: { default: true },
enableJumps: { default: false },
},
/*******************************************************************
* Lifecycle
*/
init: function () {
this.system = this.el.sceneEl.systems.physics;
this.system.addComponent(this);
const el = this.el,
data = this.data,
position = (new CANNON.Vec3()).copy(el.object3D.getWorldPosition(new THREE.Vector3()));
this.body = new CANNON.Body({
material: this.system.getMaterial('staticMaterial'),
position: position,
mass: data.mass,
linearDamping: data.linearDamping,
fixedRotation: true
});
this.body.addShape(
new CANNON.Sphere(data.radius),
new CANNON.Vec3(0, data.radius, 0)
);
this.body.el = this.el;
this.el.body = this.body;
this.system.addBody(this.body);
if (el.hasAttribute('wasd-controls')) {
console.warn('[kinema-body] Not compatible with wasd-controls, use movement-controls.');
}
},
remove: function () {
this.system.removeBody(this.body);
this.system.removeComponent(this);
delete this.el.body;
},
/*******************************************************************
* Update
*/
/**
* Checks CANNON.World for collisions and attempts to apply them to the
* element automatically, in a player-friendly way.
*
* There's extra logic for horizontal surfaces here. The basic requirements:
* (1) Only apply gravity when not in contact with _any_ horizontal surface.
* (2) When moving, project the velocity against exactly one ground surface.
* If in contact with two ground surfaces (e.g. ground + ramp), choose
* the one that collides with current velocity, if any.
*/
beforeStep: function (t, dt) {
if (!dt) return;
const el = this.el;
const data = this.data
const body = this.body;
if (!data.enableJumps) body.velocity.set(0, 0, 0);
body.position.copy(el.getAttribute('position'));
},
step: (function () {
const velocity = new THREE.Vector3(),
normalizedVelocity = new THREE.Vector3(),
currentSurfaceNormal = new THREE.Vector3(),
groundNormal = new THREE.Vector3();
return function (t, dt) {
if (!dt) return;
let body = this.body,
data = this.data,
didCollide = false,
height, groundHeight = -Infinity,
groundBody,
contacts = this.system.getContacts();
dt = Math.min(dt, this.system.data.maxInterval * 1000);
groundNormal.set(0, 0, 0);
velocity.copy(this.el.getAttribute('velocity'));
body.velocity.copy(velocity);
for (var i = 0, contact; contact = contacts[i]; i++) {
// 1. Find any collisions involving this element. Get the contact
// normal, and make sure it's oriented _out_ of the other object and
// enabled (body.collisionReponse is true for both bodies)
if (!contact.enabled) { continue; }
if (body.id === contact.bi.id) {
contact.ni.negate(currentSurfaceNormal);
} else if (body.id === contact.bj.id) {
currentSurfaceNormal.copy(contact.ni);
} else {
continue;
}
didCollide = body.velocity.dot(currentSurfaceNormal) < -EPS;
if (didCollide && currentSurfaceNormal.y <= 0.5) {
// 2. If current trajectory attempts to move _through_ another
// object, project the velocity against the collision plane to
// prevent passing through.
velocity.projectOnPlane(currentSurfaceNormal);
} else if (currentSurfaceNormal.y > 0.5) {
// 3. If in contact with something roughly horizontal (+/- 45º) then
// consider that the current ground. Only the highest qualifying
// ground is retained.
height = body.id === contact.bi.id
? Math.abs(contact.rj.y + contact.bj.position.y)
: Math.abs(contact.ri.y + contact.bi.position.y);
if (height > groundHeight) {
groundHeight = height;
groundNormal.copy(currentSurfaceNormal);
groundBody = body.id === contact.bi.id ? contact.bj : contact.bi;
}
}
}
normalizedVelocity.copy(velocity).normalize();
if (groundBody && (!data.enableJumps || normalizedVelocity.y < 0.5)) {
if (!data.enableSlopes) {
groundNormal.set(0, 1, 0);
} else if (groundNormal.y < 1 - EPS) {
groundNormal.copy(this.raycastToGround(groundBody, groundNormal));
}
// 4. Project trajectory onto the top-most ground object, unless
// trajectory is > 45º.
velocity.projectOnPlane(groundNormal);
} else if (this.system.driver.world) {
// 5. If not in contact with anything horizontal, apply world gravity.
// TODO - Why is the 4x scalar necessary.
// NOTE: Does not work if physics runs on a worker.
velocity.add(this.system.driver.world.gravity.scale(dt * 4.0 / 1000));
}
body.velocity.copy(velocity);
this.el.setAttribute('velocity', body.velocity);
this.el.setAttribute('position', body.position);
};
}()),
/**
* When walking on complex surfaces (trimeshes, borders between two shapes),
* the collision normals returned for the player sphere can be very
* inconsistent. To address this, raycast straight down, find the collision
* normal, and return whichever normal is more vertical.
* @param {CANNON.Body} groundBody
* @param {CANNON.Vec3} groundNormal
* @return {CANNON.Vec3}
*/
raycastToGround: function (groundBody, groundNormal) {
let ray,
hitNormal,
vFrom = this.body.position,
vTo = this.body.position.clone();
ray = new CANNON.Ray(vFrom, vTo);
ray._updateDirection(); // TODO - Report bug.
ray.intersectBody(groundBody);
if (!ray.hasHit) return groundNormal;
// Compare ABS, in case we're projecting against the inside of the face.
hitNormal = ray.result.hitNormalWorld;
return Math.abs(hitNormal.y) > Math.abs(groundNormal.y) ? hitNormal : groundNormal;
}
});
</script>
<body>
<a-scene physics="debug: true">
<a-box static-body position="0 0 0" height="3" width="4" color="red"></a-box>
<a-plane static-body position="0 0 0" rotation="-90 0 0" width="8" height="14" color="#7BC8A4"></a-plane>
<a-sky color="#ECECEC"></a-sky>
<a-entity kinema-body="radius: 0.8" movement-controls="fly: false" position="0 0 4" look-controls>
<a-entity camera position="0 1.6 0" ></a-entity>
</a-entity>
</a-scene>
</body>
</html>