我曾在另一个论坛上提问，但我想我对自己的问题更加清楚。
我的意图是什么？目前，我在Android设备上的WebView中使用three.js，并创建了一个场景，其中包含一个简单的框（应将其用作边界框）和一个摄像头。我的相机需要与我的android设备互动，这意味着我可以通过动态移动设备来设置位置。这些向量来自名为Direct Sparse Odometry的SLAM算法，该算法重新创建了相机位置，我也可以使用Android提供的WebViewInterface使用javascript调用这些值。我的目标是在每次更改值时都无需使用camera.lookAt（）-方法来动态地“遍历”框，因为如果我离开框，则视图不应再居中（如AR-Application ），因此应该动态创建视点，例如摄像机朝向对象的位置和旋转。我的目标是使用three.js将对象放置在现实世界对象上，以便稍后在DSO中四处走动以检测特征点，从而使用DSO对其进行扫描。整个可视化效果应使用three.js创建。
什么是DSO？DSO是一个库，用于通过检测来自Android的camera 2 API的摄像机帧中的点来跟踪真实环境。这会向我发送一个具有当前姿势的4x4转换矩阵，我尝试将其应用于three.js的相机位置。由于该算法的复杂性，我们假装这可以为我提供适当的值（以米为单位，但我还尝试将这些值乘以10或100以得到比0.XX大的结果）。
我有什么问题？即使值似乎是固定的，该框似乎也没有绝对位置。每次放置盒子时，它似乎都朝相反的方向移动。在对dso值进行了许多调整之后，我非常清楚地发现问题出在three.js上。我还尝试应用场景/相机的矩阵和/或将盒子用作子级（由于对象的遗传），但是盒子似乎在场景内没有绝对位置。另外，我也无法旋转看似真实的对象。
附上，您会找到我的代码，但p请注意，我正在使用动态虚拟值代替dso值。
<body>
<canvas id="mCanvas">
</canvas>
</body>
<script>
// Var Init
var renderer, scene, camera, box, transformControl, orbitControl, geometry, material, poseMatrix;
var mPoints = [];
//Box coordinate
var xBCordinate, yBCordinate, zBCordinate, isScaled, posVec, startPosVec, lookPos, helper;
var process = false;
var scanActive = false;
var pointArr = [];
init();
animate();
function init() {
// renderer
renderer = new THREE.WebGLRenderer({canvas: document.getElementById("mCanvas"),
alpha: true});
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
renderer.setClearColor(0xffffff, 0);
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// scene
scene = new THREE.Scene();
// camera
camera = new THREE.PerspectiveCamera(
45,
window.innerWidth / window.innerHeight,
0.1,
1000
);
camera.up.set(0, 0, 1); // Definition of coordinationsystem
// set initial scale position of camera
camera.position.x = 0;
camera.position.y = -0.5;
camera.position.z = 0.15;
scene.add(camera);
// set position to look at
camera.lookAt(0,2.5,-0.2);
// apply values
camera.updateMatrix();
// light
var light = new THREE.HemisphereLight( 0xeeeeee, 0x888888, 1 );
light.position.set( 0, -0.75, 2.5 );
scene.add(light);
placeBox();
}
function placeBox()
{
geometry = new THREE.BoxGeometry(0.5, 1, 0.5); //3,5,3
material = new THREE.MeshLambertMaterial({color: 0xfece46});
box = new THREE.Mesh(geometry, material);
box.position.set(0, 2.5, -0.2);
box.updateMatrix();
scene.add(box);
}
function animate() {
requestAnimationFrame(animate);
if(process == false){
setCurrentPose();
}
renderer.render(scene, camera);
}
function setCurrentPose(){
process = true;
// this is where I receive the position data via Android
// but lets try using random numbers between 0.01 - 0.99 (which are the results interval of dso)
moveRotateCamera();
}
function moveRotateCamera(){
// Create Vector to work with
posVec = new THREE.Vector3();
posVec.x = getRandomFloat(0.01, 0.99);
posVec.y = pgetRandomFloat(0.01, 0.99);
posVec.z = getRandomFloat(0.01, 0.99);
camera.position.x = posVec.x;
camera.position.y = (posVec.y) - 0.50; // minus initial scale position
camera.position.z = (posVec.z) + 0.15;
// camera.updateMatrix(); <- seem to change nothing such as UpdateWorldMatrix() etc.
// camera rotation tried to calculate with quaternions (result NaN) and/or euler by using former and current point.
process = false;
}
function getRandomFloat(min, max) {
return Math.random() * (max - min) + min;
}
// My attempts in trying to calculate the rotation
/*
function setQuaternionRotation(poseMatrix){
// TODO: delete if not needed!
// adapted from http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/index.htm, 2.12.2019, 2.34pm
mQuaternion = new THREE.Quaternion();
// Calculate Angle w
mQuaternion.w = ((Math.sqrt(Math.max(0, (1.0 + poseMatrix.elements[0] + poseMatrix.elements[5] + poseMatrix.elements[10])))/2.0));
//Sign x,y,z values of quaternion
mQuaternion.x = ((Math.sqrt(Math.max(0, (1.0 + poseMatrix.elements[0] - poseMatrix.elements[5] - poseMatrix.elements[10])))/2.0));
mQuaternion.y = ((Math.sqrt(Math.max(0, (1.0 - poseMatrix.elements[0] + poseMatrix.elements[5] - poseMatrix.elements[10])))/2.0));
mQuaternion.y = ((Math.sqrt(Math.max(0, (1.0 - poseMatrix.elements[0] - poseMatrix.elements[5] + poseMatrix.elements[10])))/2.0));
//Sign element values
mQuaternion.x = (Math.sign(mQuaternion.x * (poseMatrix.elements[6] - poseMatrix.elements[9])));
mQuaternion.y = (Math.sign(mQuaternion.y * (poseMatrix.elements[8] - poseMatrix.elements[2])));
mQuaternion.z = (Math.sign(mQuaternion.z * (poseMatrix.elements[1] - poseMatrix.elements[4])));
// debug
console.log("QuaternionVal: "+mQuaternion.x+ ", " +mQuaternion.y+", "+mQuaternion.z+", "+mQuaternion.w);
camera.applyQuaternion(mQuaternion);
camera.quaternion.normalize();
// debug
console.log("newCamRotation: "+camera.rotation.x +", "+camera.rotation.y+", "+ camera.rotation.z);
// camera.updateMatrix(true);
}
*/
</script>
您有什么建议吗？
非常感谢！
最诚挚的问候，
FWIW。我认为部分原因是该框未围绕相机旋转居中。除了使用球面坐标来移动相机之外，我还通过将框居中于原点来调整了小提琴。这样可以使相机与框保持均匀的距离，并且框以旋转为中心，似乎不会围绕视口移动...
<body>
<canvas id="mCanvas">
</canvas>
</body>
<script src="https://threejs.org/build/three.js"></script>
<script>
// Var Init
var renderer, scene, camera, box, transformControl, orbitControl, geometry, material, poseMatrix;
var mPoints = [];
//Box coordinate
var xBCordinate, yBCordinate, zBCordinate, isScaled, posVec, startPosVec, lookPos, helper;
var process = false;
var scanActive = false;
var pointArr = [];
var cameraSpherical;
init();
animate();
function init() {
// renderer
renderer = new THREE.WebGLRenderer({canvas: document.getElementById("mCanvas"),
alpha: true});
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
renderer.setClearColor(0xffffff, 0);
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// scene
scene = new THREE.Scene();
// camera
camera = new THREE.PerspectiveCamera(
45,
window.innerWidth / window.innerHeight,
0.1,
1000
);
camera.up.set(0, 0, 1); // Definition of coordinationsystem
// set initial scale position of camera
camera.position.x = 0;
camera.position.y = -0.5;
camera.position.z = 0.15;
scene.add(camera);
cameraSpherical = new THREE.Spherical( camera.position );
// set position to look at
camera.lookAt(0,2.5,-0.2);
// apply values
camera.updateMatrix();
// light
var light = new THREE.HemisphereLight( 0xeeeeee, 0x888888, 1 );
light.position.set( 0, -0.75, 2.5 );
scene.add(light);
placeBox();
}
function placeBox()
{
geometry = new THREE.BoxGeometry(0.5, 1, 0.5); //3,5,3
material = new THREE.MeshLambertMaterial({color: 0xfece46});
box = new THREE.Mesh(geometry, material);
box.position.set(0, 0, 0);
box.updateMatrix();
scene.add(box);
}
function animate() {
requestAnimationFrame(animate);
if(process == false){
setCurrentPose();
}
renderer.render(scene, camera);
}
function setCurrentPose(){
process = true;
// this is where I receive the position data via Android
// but lets try using random numbers between 0.01 - 0.99 (which are the results interval of dso)
moveRotateCamera();
}
function moveRotateCamera(){
// Create Vector to work with
/* posVec = new THREE.Vector3();
posVec.x = getRandomFloat(0.01, 0.05);
posVec.y = getRandomFloat(0.01, 0.05);
posVec.z = getRandomFloat(0.01, 0.02);
camera.position.x += posVec.x;
camera.position.y += posVec.y; // minus initial scale position
camera.position.z += posVec.z;
*/
cameraSpherical.radius = 5;
cameraSpherical.phi += getRandomFloat(0.001, 0.015);
cameraSpherical.theta += getRandomFloat(0.001, 0.015);
let xyz = new THREE.Vector3().setFromSpherical( cameraSpherical );
camera.position.x = xyz.x;
camera.position.y = xyz.y;
camera.position.z = xyz.z;
camera.lookAt(0,0,0);
camera.updateMatrix();
// camera.updateMatrix(); <- seem to change nothing such as UpdateWorldMatrix() etc.
// camera rotation tried to calculate with quaternions (result NaN) and/or euler by using former and current point.
process = false;
}
function getRandomFloat(min, max) {
return Math.random() * (max - min) + min;
}
// My attempts in trying to calculate the rotation
/*
function setQuaternionRotation(poseMatrix){
// TODO: delete if not needed!
// adapted from http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/index.htm, 2.12.2019, 2.34pm
mQuaternion = new THREE.Quaternion();
// Calculate Angle w
mQuaternion.w = ((Math.sqrt(Math.max(0, (1.0 + poseMatrix.elements[0] + poseMatrix.elements[5] + poseMatrix.elements[10])))/2.0));
//Sign x,y,z values of quaternion
mQuaternion.x = ((Math.sqrt(Math.max(0, (1.0 + poseMatrix.elements[0] - poseMatrix.elements[5] - poseMatrix.elements[10])))/2.0));
mQuaternion.y = ((Math.sqrt(Math.max(0, (1.0 - poseMatrix.elements[0] + poseMatrix.elements[5] - poseMatrix.elements[10])))/2.0));
mQuaternion.y = ((Math.sqrt(Math.max(0, (1.0 - poseMatrix.elements[0] - poseMatrix.elements[5] + poseMatrix.elements[10])))/2.0));
//Sign element values
mQuaternion.x = (Math.sign(mQuaternion.x * (poseMatrix.elements[6] - poseMatrix.elements[9])));
mQuaternion.y = (Math.sign(mQuaternion.y * (poseMatrix.elements[8] - poseMatrix.elements[2])));
mQuaternion.z = (Math.sign(mQuaternion.z * (poseMatrix.elements[1] - poseMatrix.elements[4])));
// debug
console.log("QuaternionVal: "+mQuaternion.x+ ", " +mQuaternion.y+", "+mQuaternion.z+", "+mQuaternion.w);
camera.applyQuaternion(mQuaternion);
camera.quaternion.normalize();
// debug
console.log("newCamRotation: "+camera.rotation.x +", "+camera.rotation.y+", "+ camera.rotation.z);
// camera.updateMatrix(true);
}
*/
</script>不确定是否对您的前进方向有帮助，但希望它能为您提供一些启示。