javascript-如何转换THREE.PointCloud对象中的顶点?
作者:互联网
我在尝试着:
>绘制一个约有三个THREE.PointCloud对象.从Web应用程序发送点的15万个点.
>缩放THREE.PointCloud对象中的点以实现类似于以下结果(使用MayaVi渲染):
问题是:
>传递给THREE.PointCloud对象的数据似乎不正确
>在three.js中渲染时,由于未知原因,点被排列成八个立方体(我不对点应用任何缩放或变换)
服务器响应示例(我在这篇文章的底部提供了示例数据):
{'geometry': [[-156, 65, 89],
[268, 84, 337],
[-205, 68, 170],
[-87, 69, 52],
...
[289, 81, 143],
[141, 78, 280],
[403, 75, 351]],
'metadata': {'max': {'x': 421, 'y': 105, 'z': 458},
'min': {'x': -335, 'y': 63, 'z': 39}}}
用于创建点云的three.js代码:
var container;
var scene, camera, renderer, controls;
var geometry, material, mesh;
init();
animate();
function init() {
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera(27, window.innerWidth / window.innerHeight, 5, 5000);
camera.position.z = 2750;
//Add a buffer geometry for particle system
var geometry = new THREE.BufferGeometry();
var particles = {{ len(topology['geometry']) }};
var geometry = new THREE.BufferGeometry();
var positions = new Float32Array(particles * 3);
var colors = new Float32Array(particles * 3);
var color = new THREE.Color();
var i = 0;
{% for point in topology['geometry'] %}
var x = {{ point[0] }};
var y = {{ point[1] }};
var z = {{ point[2] }};
//Store the position of the point
positions[i] = x;
positions[i + 1] = y;
positions[i + 2] = z;
//Assign a colour to the point
color.setRGB(0.42, 0.42, 0.42);
colors[i] = color.r;
colors[i + 1] = color.g;
colors[i + 2] = color.b;
i+=1;
{% end %}
geometry.addAttribute('position', new THREE.BufferAttribute(positions, 3));
geometry.addAttribute('color', new THREE.BufferAttribute(colors, 3));
geometry.computeBoundingSphere();
var material = new THREE.PointCloudMaterial({ size: 15, vertexColors: THREE.VertexColors });
particleSystem = new THREE.PointCloud(geometry, material);
scene.add(particleSystem);
//Lights
light = new THREE.DirectionalLight(0xffffff);
light.position.set(1, 1, 1);
scene.add(light);
//Set up renderer
renderer = new THREE.WebGLRenderer({ antialias:false });
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setPixelRatio(window.devicePixelRatio);
//Attach renderer to #container DOM element
container = document.getElementById('container');
container.appendChild(renderer.domElement);
//Add window listener for resize events
window.addEventListener('resize', onWindowResize, false);
//Call render loop
animate();
}
function onWindowResize(){
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);
render();
}
function animate() {
requestAnimationFrame(animate);
renderer.render(scene, camera);
}
function render(){
renderer.render(scene, camera);
}
场景最终看起来像这样:
有什么建议么?我使用了以下示例代码,但是我无法为数据集中的点正确实现缩放:http://threejs.org/examples/#webgl_buffergeometry_particles
链接到我正在使用的数据样本(2MB,180k行):https://gist.githubusercontent.com/TylerJFisher/659e3e233f8aa458feee/raw/889c0dd0093fd0476094af48488aab62c8666271/topology.asc
解决方法:
我使用了您的样本数据.将其放入数组中,如下所示:
var data = [
"-156 65 89",
"268 84 337",
"-205 68 170",
"-87 69 52",
...
];
并对PointCloud使用THREE.Geometry():
var geometry = new THREE.Geometry();
var colors = [];
for ( var x = 0; x < data.length; x++){
var pointCoord = data[ x ].split(" ");
if ( pointCoord.length != 3 ) continue;
var currentColor = new THREE.Color( 0.5, 1, 0.5 );
colors.push( currentColor );
geometry.vertices.push(
new THREE.Vector3(
pointCoord[2],
pointCoord[1],
pointCoord[0]
)
);
};
//
console.log( geometry.vertices.length );
geometry.colors = colors;
var material = new THREE.PointCloudMaterial( { size: 1, vertexColors: THREE.VertexColors } );
particleSystem = new THREE.PointCloud( geometry, material );
scene.add( particleSystem );
同样,在地理数据中,坐标x和y始终会交换(在这种情况下,存在x和z).如果您不这样做,那么您将获得镜像对象.这就是为什么我把它作为
new THREE.Vector3(
pointCoord[2],
pointCoord[1],
pointCoord[0]
)
代替
new THREE.Vector3(
pointCoord[0],
pointCoord[1],
pointCoord[2]
)
结果在这里:geodata
是的,示例数据中的某些行似乎不正确.表示它们具有1或2个值而不是3个值.
标签:3d,three-js,javascript 来源: https://codeday.me/bug/20191120/2045576.html