在这里,我试图根据鼠标指针位置放大对象(比如立方体)。在这里我google了一下,发现可以在D3 JS中实现,也可以通过捕获鼠标指针3D点并将其传递给鼠标滚轮函数来实现。
这是 fiddle https://jsfiddle.net/fpt9hswo/
var scene, renderer, camera;
var cube;
var controls;
var containerWidth = window.innerWidth,
containerHeight = window.innerHeight;
init();
animate();
function init() {
configureRenderer();
scene = new THREE.Scene();
configureCube();
configureCamera();
configureLight();
configureControls();
fitAll();
}
function configureRenderer() {
renderer = new THREE.WebGLRenderer({
antialias: true,
alpha: true
});
renderer.setSize(containerWidth, containerHeight);
document.body.appendChild(renderer.domElement);
}
function configureCube() {
var cubeGeometry = new THREE.BoxGeometry(20, 20, 20);
var cubeMaterial = new THREE.MeshLambertMaterial({
color: 0xff0000
});
cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
cube.position.set(50, 0, 0);
scene.add(cube);
}
function configureCamera() {
camera = new THREE.PerspectiveCamera(45, containerWidth / containerHeight, 1, 1000);
camera.position.set(0, 160, 400);
camera.lookAt(scene);
}
function configureLight() {
pointLight = new THREE.PointLight(0xffffff, 1.0, 100000);
pointLight.position.set(0, 300, 200);
scene.add(pointLight);
}
function configureControls() {
controls = new THREE.TrackballControls(camera, renderer.domElement);
// configuration of controls
controls.rotateSpeed = 5.0;
controls.zoomSpeed = 5.0;
controls.panSpeed = 2.0;
controls.staticMoving = true;
controls.dynamicDampingFactor = 0;
}
function fitAll() {
// Calculate bounding box of the whole scene
var boundingBoxOfNode = new THREE.Box3().setFromObject(scene),
centerOfGravity = boundingBoxOfNode.getCenter();
/************* CAMERA *************************/
camera.position.addVectors(camera.position, centerOfGravity);
camera.lookAt(centerOfGravity);
//new camera positions will be set here
//Eg: camera.position.set(newCamera.x,newCamera.y,newCamera.z);
//Similarly new camera rotation and quaternion coordinates will be set
//Eg: camera.rotation.set(newCamera.rotatex,newCamera.rotatey,newCamera.rotatez);
//Eg: camera.quaternion.set(newCamera.qw,newCamera.qx,newCamera.qy,newCamera.qz);
/************* CONTROLS *************************/
controls.target.set(centerOfGravity.x, centerOfGravity.y, centerOfGravity.z);
//new controls.target values will be set here
//Eg: controls.target.set(newCamera.targetx,newCamera.targety,newCamera.targetz);
}
function animate() {
controls.update();
requestAnimationFrame(animate);
renderer.render(scene, camera);
}
提前致谢
最佳答案
要执行您想要的操作,您必须实现自己的鼠标滚轮事件,并且必须禁用 THREE.TrackballControls
的默认缩放:
controls = new THREE.TrackballControls(camera, renderer.domElement);
//...
controls.zoomSpeed = 0.0;
添加车轮事件:
例如
renderer.domElement.addEventListener("wheel", event => {
const delta = event.deltaY;
// [...]
}
通过在世界的深度移动相机位置,可以实现透视投影的放大。
如果你想缩放到一个点,这可以通过沿着一条射线移动相机来实现,从相机位置到光标(鼠标)位置并平行移动目标位置。
可以轻松找到标准化设备空间中从相机到光标的射线上的一个点。在归一化设备空间中,所有坐标都在 [-1, 1] 范围内,所有具有相同 x 和 y 坐标的点都在同一射线上。如果 z 坐标为 -1,则该点位于近平面;如果 z 为 1,则该点位于远平面。
例如远平面上的 NDC 点和通过光标的射线:
let x = 2 * event.clientX / window.innerWidth - 1;
let y = 1 - 2 * event.clientY / window.innerHeight;
let cursorpos = new THREE.Vector3(x, y, 1);
通过 THREE.Vector3.unproject()
可以将规范化设备空间中的这个点转换为世界空间中的一个点.函数的参数必须是 THREE.Camera
它定义了 View 和投影:
cursorpos.unproject(camera);
相机移动的方向是世界空间中从相机位置到光标位置的归一化方向:
let dir = new THREE.Vector3().copy(cursorpos).sub(camera.position).normalize();
根据方向和鼠标滚轮增量计算移动并更新相机和THREE.TrackballControls
:
let shift = new THREE.Vector3().copy(dir).multiplyScalar(delta * 0.1);
camera.position.add(shift);
controls.position0.add(shift);
controls.target.add(shift);
查看示例,其中我将建议应用于问题的代码:
var scene, renderer, camera;
var cube;
var controls;
var containerWidth = window.innerWidth,
containerHeight = window.innerHeight;
init();
animate();
function init() {
configureRenderer();
scene = new THREE.Scene();
configureCube();
configureCamera();
configureLight();
configureControls();
}
function configureRenderer() {
renderer = new THREE.WebGLRenderer({
antialias: true,
alpha: true
});
renderer.setSize(containerWidth, containerHeight);
document.body.appendChild(renderer.domElement);
window.onresize = function() {
renderer.setSize(window.innerWidth, window.innerHeight);
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
if (controls)
controls.handleResize();
}
renderer.domElement.addEventListener("wheel", event => {
const delta = event.deltaY;
let x = 2 * event.clientX / window.innerWidth - 1;
let y = 1 - 2 * event.clientY / window.innerHeight;
let cursorpos = new THREE.Vector3(x, y, 1);
cursorpos.unproject(camera);
let dir = new THREE.Vector3().copy(cursorpos).sub(camera.position).normalize();
let shift = new THREE.Vector3().copy(dir).multiplyScalar(delta * 0.1);
camera.position.add(shift);
controls.position0.add(shift);
controls.target.add(shift);
});
}
function configureCube() {
var cubeGeometry = new THREE.BoxGeometry(20, 20, 20);
var cubeMaterial = new THREE.MeshLambertMaterial({
color: 0xff0000
});
cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
cube.position.set(50, 0, 0);
scene.add(cube);
}
function configureCamera() {
camera = new THREE.PerspectiveCamera(45, containerWidth / containerHeight, 1, 1000);
camera.position.set(0, 160, 400);
camera.lookAt(scene);
}
function configureLight() {
pointLight = new THREE.PointLight(0xffffff, 1.0, 100000);
pointLight.position.set(0, 300, 200);
scene.add(pointLight);
}
function configureControls() {
controls = new THREE.TrackballControls(camera, renderer.domElement);
// configuration of controls
controls.rotateSpeed = 5.0;
controls.zoomSpeed = 0.0;
controls.panSpeed = 2.0;
controls.staticMoving = true;
controls.dynamicDampingFactor = 0;
}
function animate() {
controls.update();
requestAnimationFrame(animate);
renderer.render(scene, camera);
}
<script src="https://threejs.org/build/three.min.js"></script>
<script src="https://threejs.org/examples/js/controls/TrackballControls.js"></script>
关于javascript - 根据鼠标指针放大对象,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/55951601/