拿到手的这个倾斜摄影数据是一个文件夹，里面放置osgb.s3c，metadata.xml，和一个Data目录。Data目录有一堆Tile文件夹，里面放置了很多的osgb后缀的文件-Smart3D处理过的Open Scene Graph Binary文件。
注：
metadata.xml中的信息有SRS和SRSOrigin，分别对应模型建立的坐标系，和原点位置。如下，SRSOrigin可以在epsg.io网站上查EPSG：4544下的地点，就是该模型的中心位置。
<SRS>EPSG:4544</SRS> <!--Origin in Spatial Reference System--> <SRSOrigin>701356,3307142,0</SRSOrigin>
查了一下网络，需要用一些工具转化该数据集才能在Cesium中显示，因为Cesium目前只支持3D tiles。
1、 https://github.com/fanvanzh/3dtiles 这里下载预编译好的一个工具
windows版预编译好的下载：
链接：https://pan.baidu.com/s/1jZcSVIUoYNtMQdxbo4xJCQ
提取码：qjsj
2、命令行打开，使用下面的命令把拿到手的文件夹里的数据转化成3d tiles，会生成在./output下
3dtile -f osgb -i ./ -o ./output
3、拷贝./output里的3d tiles文件到Cesium的工程目录，用下面的代码显示
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
<meta name="description" content="Demo the minimum set of options needed to remove all external dependencies, for offline operation.">
<meta name="cesium-sandcastle-labels" content="Beginner, Showcases">
<title>Cesium Demo</title>
<script type="text/javascript" src="../Sandcastle-header.js"></script>
<script type="text/javascript" src="../../../ThirdParty/requirejs-2.1.20/require.js"></script>
<script type="text/javascript">
require.config({
baseUrl : '../../../Source',
waitSeconds : 60
});
</script>
</head>
<body class="sandcastle-loading" data-sandcastle-bucket="bucket-requirejs.html">
<style>
@import url(../templates/bucket.css);
</style>
<div id="cesiumContainer" class="fullSize"></div>
<div id="loadingOverlay"><h1>Loading...</h1></div>
<div id="toolbar"></div>
<script id="cesium_sandcastle_script">
function startup(Cesium) {
'use strict';
var fixGltf = function(gltf) {
if (!gltf.extensionsUsed) {
return;
}
var v = gltf.extensionsUsed.indexOf('KHR_technique_webgl');
var t = gltf.extensionsRequired.indexOf('KHR_technique_webgl');
// 中招了。。
if (v !== -1) {
gltf.extensionsRequired.splice(t, 1, 'KHR_techniques_webgl');
gltf.extensionsUsed.splice(v, 1, 'KHR_techniques_webgl');
gltf.extensions = gltf.extensions || {};
gltf.extensions['KHR_techniques_webgl'] = {};
gltf.extensions['KHR_techniques_webgl'].programs = gltf.programs;
gltf.extensions['KHR_techniques_webgl'].shaders = gltf.shaders;
gltf.extensions['KHR_techniques_webgl'].techniques = gltf.techniques;
var techniques = gltf.extensions['KHR_techniques_webgl'].techniques;
gltf.materials.forEach(function (mat, index) {
gltf.materials[index].extensions['KHR_technique_webgl'].values = gltf.materials[index].values;
gltf.materials[index].extensions['KHR_techniques_webgl'] = gltf.materials[index].extensions['KHR_technique_webgl'];
var vtxfMaterialExtension = gltf.materials[index].extensions['KHR_techniques_webgl'];
for (var value in vtxfMaterialExtension.values) {
var us = techniques[vtxfMaterialExtension.technique].uniforms;
for (var key in us) {
if (us[key] === value) {
vtxfMaterialExtension.values[key] = vtxfMaterialExtension.values[value];
delete vtxfMaterialExtension.values[value];
break;
}
}
};
});
techniques.forEach(function (t) {
for (var attribute in t.attributes) {
var name = t.attributes[attribute];
t.attributes[attribute] = t.parameters[name];
};
for (var uniform in t.uniforms) {
var name = t.uniforms[uniform];
t.uniforms[uniform] = t.parameters[name];
};
});
}
}
Object.defineProperties(Cesium.Model.prototype, {
_cachedGltf: {
set: function (value) {
this._vtxf_cachedGltf = value;
if (this._vtxf_cachedGltf && this._vtxf_cachedGltf._gltf) {
fixGltf(this._vtxf_cachedGltf._gltf);
}
},
get: function () {
return this._vtxf_cachedGltf;
}
}
});
//Sandcastle_Begin
// This is an example of using Cesium "Offline", meaning disconnected from the
// external Internet. It must still be served from a local web server, but
// does not rely on any outside resources or services. For more info, see:
// https://github.com/AnalyticalGraphicsInc/cesium/wiki/Offline-Guide
var viewer = new Cesium.Viewer('cesiumContainer', {
imageryProvider : Cesium.createTileMapServiceImageryProvider({
url : Cesium.buildModuleUrl('Assets/Textures/NaturalEarthII')
}),
baseLayerPicker : false,
geocoder : false
});
var tileset = new Cesium.Cesium3DTileset({
url: '../../SampleData/Cesium3DTiles/fromyuzs/tileset.json'
});
viewer.scene.primitives.add(tileset);
viewer.zoomTo(tileset);
//viewer.scene.debugShowGlobeDepth = true;
//Sandcastle_End
Sandcastle.finishedLoading();
}
if (typeof Cesium !== 'undefined') {
startup(Cesium);
} else if (typeof require === 'function') {
require(['Cesium'], startup);
}
</script>
</body>
</html>
注意：代码使用了网络上找到的fixGltf方式，否则Cesium显示这个3d tiles的时候会出错。