viv*_*yay 6 javascript three.js
我正在使用threejs构建3D可视化和交互式应用程序.以下是我想在此应用程序中提供的主要功能:
在这个用户应该能够:
我正在关注巨大的threejs 文档 及其示例列表,这对我帮助很大,而且我能够实现一点点.
此外,我遇到了一个有用的threejs检查员Chrome Ext.
这三个检查员Chrome Ext全部完成了我想要实现的一切,但不幸的是我无法理解它是如何工作的以及它如何能够选择和操作Obj文件的各个部分.
我现在使用以下代码使用threejs来显示,旋转和缩放Obj文件.
if ( ! Detector.webgl ) Detector.addGetWebGLMessage();
var container, camera, controls, scene, renderer, mesh;
var mtlObject = {};
var strDownloadMime = "image/octet-stream";
init();
animate();
function init() {
var saveLink = document.createElement('div');
saveLink.style.position = 'absolute';
saveLink.style.top = '10px';
saveLink.style.width = '100%';
saveLink.style.color = 'white !important';
saveLink.style.textAlign = 'center';
saveLink.innerHTML ='<a href="#" id="saveLink">Save Frame</a>';
document.body.appendChild(saveLink);
document.getElementById("saveLink").addEventListener('click', saveAsImage);
renderer = new THREE.WebGLRenderer({
preserveDrawingBuffer: true
});
camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 1, 1000 );
camera.position.z = 500;
controls = new THREE.TrackballControls( camera );
controls.rotateSpeed = 2.0;
controls.zoomSpeed = 2.0;
controls.panSpeed = 2.0;
controls.noZoom = false;
controls.noPan = false;
controls.staticMoving = true;
controls.dynamicDampingFactor = 0.3;
controls.keys = [ 65, 83, 68 ];
controls.addEventListener( 'change', render );
// world
scene = new THREE.Scene();
var ambient = new THREE.AmbientLight( 0x444444 );
scene.add( ambient );
var directionalLight = new THREE.DirectionalLight( 0xffeedd );
directionalLight.position.set( 0, 0, 1 ).normalize();
scene.add( directionalLight );
// model
var onProgress = function ( xhr ) {
if ( xhr.lengthComputable ) {
var percentComplete = xhr.loaded / xhr.total * 100;
console.log( Math.round(percentComplete, 2) + '% downloaded' );
}
};
var onError = function ( xhr ) { };
//mtl loader
THREE.Loader.Handlers.add( /\.dds$/i, new THREE.DDSLoader() );
var mtlLoader = new THREE.MTLLoader();
mtlLoader.setPath( 'obj/' );
mtlLoader.load( 'arm.mtl', function( materials ) {
materials.preload();
var objLoader = new THREE.OBJLoader();
objLoader.setMaterials( materials );
objLoader.setPath( 'obj/' );
objLoader.load( 'arm.obj', function ( object ) {
object.name = "object_name";
object.position.y = - 95;
scene.add( object );
//As 'TheJim01' suggested
//I have used an object variable.
//then traverse through the scene nodes
//and target some particular parts of the obj as:
var nameToObject = {};
scene.traverse( function( node ) {
nameToObject[node.name] = node;
if (node.name == ("Pad01")) {
node.visible = false;
}
if (node.name == ("Arm_01")) {
node.visible = false;
}
if (node.name == ("Pad02")) {
node.visible = false;
}
if (node.name == ("Arm_02")) {
node.visible = false;
}
});
}, onProgress, onError );
});
// lights
var light = new THREE.DirectionalLight( 0xffffff );
light.position.set( 1, 1, 1 );
scene.add( light );
var light = new THREE.DirectionalLight( 0x002288 );
light.position.set( -1, -1, -1 );
scene.add( light );
var light = new THREE.AmbientLight( 0x222222 );
scene.add( light );
// renderer
renderer = new THREE.WebGLRenderer( { antialias: false } );
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( window.innerWidth, window.innerHeight );
container = document.getElementById( 'container' );
container.appendChild( renderer.domElement );
//
window.addEventListener( 'resize', onWindowResize, false );
//
render();
}
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize( window.innerWidth, window.innerHeight );
controls.handleResize();
render();
}
function animate() {
requestAnimationFrame( animate );
controls.update();
}
function render() {
renderer.render( scene, camera );
}
//my next challenge is to save the canvas as image
//after making all the changes to the obj file
function saveAsImage() {
var imgData, imgNode;
try {
var strMime = "image/jpeg";
imgData = renderer.domElement.toDataURL(strMime);
saveFile(imgData.replace(strMime, strDownloadMime), "test.jpg");
} catch (e) {
console.log(e);
return;
}
}
var saveFile = function (strData, filename) {
var link = document.createElement('a');
if (typeof link.download === 'string') {
document.body.appendChild(link); //Firefox requires the link to be in the body
link.download = filename;
link.href = strData;
link.click();
document.body.removeChild(link); //remove the link when done
} else {
location.replace(uri);
}
}
$(document).ready(function() {
//Set Color of the Obj parts accordingly
$('#armblock').on('click', function(){
$(this).children('ul').slideToggle(400);
$(this).children('ul').children('li').on('click', function(){
$color = new THREE.Color($(this).css('backgroundColor'));
var selectedColor = '#' + $color.getHexString();
//As 'TheJim01' suggested
//I have used and object variable.
//then traverse through the scene nodes
//and target some perticular parts of the obj as:
var nameToObject = {};
scene.traverse( function( node ) {
nameToObject[node.name] = node;
if (node.name == ("Arm_01")) {
node.visible = true;
nameToObject["Arm_01"].material.color.set(selectedColor);
}
if (node.name == ("Arm_02")) {
node.visible = true;
nameToObject["Arm_02"].material.color.set(selectedColor);
}
});
});
});
$('#padblock').on('click', function(){
$(this).children('ul').slideToggle(400);
$(this).children('ul').children('li').on('click', function(){
$color = new THREE.Color($(this).css('backgroundColor'));
var selectedColor = '#' + $color.getHexString();
//As 'TheJim01' suggested
//I have used an object variable.
//then traverse through the scene nodes
//and target some particular parts of the obj as:
var nameToObject = {};
scene.traverse( function( node ) {
nameToObject[node.name] = node;
if (node.name == ("Pad01")) {
node.visible = true;
nameToObject["Pad01"].material.color.set(selectedColor);
}
if (node.name == ("Pad02")) {
node.visible = true;
nameToObject["Pad02"].material.color.set(selectedColor);
}
});
});
});
});
如果有人可以帮我解决这个问题.在此先感谢,如果我遗漏了任何内容,请发表评论.
更新
下一个挑战
PS
TheJim01帮助我理解了遍历obj文件及其部分的基本但非常重要的概念.这导致我至少建立更接近我想要的东西.
Three.js检查器所做的就是解析场景，并在交互式 UI 中显示对象的各种属性。
假设您有一个按如下方式排列的 OBJ 文件：
bike
frame
seat
drive
pedals
frontSprocket
chain
rearSprocket
rearWheel
steering
handlebars
fork
frontWheel
OBJLoader将创建一个像这样的场景层次结构：
bike // THREE.Group
frame // THREE.Mesh
seat // THREE.Mesh
drive // THREE.Group
pedals // THREE.Mesh
frontSprocket // THREE.Mesh
chain // THREE.Mesh
rearSprocket // THREE.Mesh
rearWheel // THREE.Mesh
steering // THREE.Group
handlebars // THREE.Mesh
fork // THREE.Mesh
frontWheel // THREE.Mesh
Three.js 检查器使用对象名称显示相同的层次结构。当您单击树中的对象时，它会引用场景中的对象，并获取/显示其属性，例如其position、rotation、状态等。当您在Three.js 检查器visibleUI中进行更改时，它会设置场景中对象的值，从而导致您看到的变化。
您可以自己完成所有这些工作，甚至不需要如此笼统。假设您想要创建对象名称到场景对象的映射以方便参考（搜索场景足够快，但它是递归的）。所以你可以这样做：
var nameToObject = {};
scene.traverse(function(node){
// watch out for duplicate empty names!
nameToObject[node.name] = node;
});
（这并没有给你层次结构，但这只是一个例子。）
现在您可以按名称获取和更新任何对象：
// enlarge the rear tire
nameToObject["rearTire"].scale.addScalar(0.1);
您可以读取和设置对象的所有属性。例如，如果MTLLoader为框架创建了基本材质，您可以执行以下操作：
// make the frame red
nameToObject["frame"].material.color.setRGB(1.0, 0.0, 0.0);
或者您可以直接更换整个材料。
对于替换对象的示例，假设您已经加载了一个Mesh名为newRearTire...
// replace the rear tire
var drive = nameToObject["drive"]; // the parent of rearTire
drive.remove(nameToObject["rearTire"]);
drive.add(newRearTire);
（当然，此时您需要重新构建名称映射。）
这些只是非常一般的示例，但应该可以帮助您入门。如果您在访问数据时遇到任何问题，请发表评论，我会尽力予以澄清。