README

aframe-loader-3dtiles-component

An A-Frame component for displaying OGC 3D Tiles based on nytimes/three-loader-3dtiles.

Demos — API — Installation — Usage — Contributing — Roadmap

The loader uses the loaders.gl library, which is part of the vis.gl platform, openly governed by the Urban Computing Foundation. Development of the loader started at The New York Times R&D as an effort deliver massive 3D and Geographical journalism to readers. This A-Frame components makes 3D Tiles more accessible to creators and brings immersitve journalism into mixed realities on the web.

Demos

Demos are available here.

Installation

Browser

The following example loads the library from CDN, as well as missing required components for handling KTX2/basis_universal glTFs.

<head>
  <title>My A-Frame Scene</title>
  <script src="https://aframe.io/releases/1.2.0/aframe.min.js"></script>
  <script src='https://cdn.jsdelivr.net/npm/three@0.133.0/examples/js/utils/WorkerPool.js'></script>
  <script src='https://cdn.jsdelivr.net/npm/three@0.133.0/examples/js/loaders/KTX2Loader.js'></script>
  <script src="https://cdn.jsdelivr.net/npm/aframe-loader-3dtiles-component/dist/aframe-loader-3dtiles-component.min.js"></script>
</head>

Usage

The following example sets up a basic scene with a RealityCapture photogrammetry model.

<body>
    <a-scene environment="preset: default">
      <a-camera id="camera"></a-camera>
      <a-entity
        id="freeman-tiles"
        position="0 2.6 0"
        rotation="-90 180 0"
        scale="2 2 2"
        loader-3dtiles="
         url: https://int.nyt.com/data/3dscenes/ONA360/TILESET/0731_FREEMAN_ALLEY_10M_A_36x8K__10K-PN_50P_DB/tileset_tileset.json; 
         maximumSSE: 48;
         cameraEl: #camera;
        "
      >
      </a-entity>
    </a-scene>
</body>

npm

Install via npm:

npm install aframe-loader-3dtiles-component

Then require and use.

require('aframe');
require('aframe-loader-3dtiles-component');

API

Property	Type	Description	Default Value
url	string	The URL of the tileset. For example if using Cesium ION, it would have the form: https://assets.cesium.com/[ASSET_ID]/tileset.json. Can be updated at runtime.	''
cameraEl	selector	A selector for the camera whose position is used to determine which tiles to display at which LOD. If a `cameraEl` value is not provided then component uses `document.querySelector('a-scene').camera` to find `a-camera` primitive or entity with `camera` component. For more info see Camera Requirement note below. The component automatically switches the camera in response to the `camera-set-active` event.	''
maximumSSE	int	maximumScreenSpaceError (Optional) determines the distance from tiles in which they are refined, depending on their geometrical size. Increase the value to load lower LOD tiles from the same view distance (increases performance). Cannot be updated at runtime.	16
maximumMem	int	maximumMemoryUsage (Optional) determines maximum GPU memory (MB) to use for displaying tiles. May go over the limit if tiles within the camera viewport exceed that amount. Cannot be updated at runtime.	32
distanceScale	number	(Optional) 0-1 scale for the LOD quality. A lower value loads tiles from lower LODs (increases performance). Can be updated at runtime.	1.0
pointcloudColoring	string	(Optional) When viewing point clouds, which datum determines the color of a point. Possible values: 'white', 'intensity', 'classification', 'elevation', 'rgb'.	'white'
pointcloudElevationRange	array	(Optional) When viewing point clouds colored by their elevation, what are the minimum and maximum height values.	0, 400
wireframe	boolean	(Optional) When viewing b3dm (mesh) tiles, show meshes as wireframe. Can be updated at runtime.	false
showStats	boolean	(Optional) Attaches a box with tilestats to the scene, useful for debugging.	false
cesiumIONToken	string	(Optional) A Cesium ION access token when loading tilesets from Cesium ION.	''

Camera Requirement

To use the loader-3dtiles component, your A-Frame scene must have a camera defined using <a-camera> or the camera component . The component will attempt to use one of these automatically, or you can specify your own selector with the cameraEl property.

The camera is used to provide dynamic levels of detail (LOD) for 3D tiles. If no suitable camera is found the tiles will not display and an error is shown on the console 3D Tiles: Please add an active camera or specify the target camera via the cameraEl property.

Compatability with THREE.Cache

Currently, three-loader-3dtiles does not support the use of THREE.Cache which is enabled by default in A-Frame. In its default setting, the cache does not recognize repeated loads of tiles, which causes the cache to overflow. Therefore, the loader-3dtiles component disables THREE.Cache if it is enabled and displays a warning: 3D Tiles loader cannot work with THREE.Cache, disabling.

Contributing

Refer to CONTRIBUTING.MD for general contribution instructions.

Roadmap

Suggestions for future work include:

More elaborate test cases.
Better integration with the inspector.
Test AR scenarios.
Test point-cloud scenarios.
Could THREE.Cache be used manually?
Conversion to Typescript.

This repository is maintained by the Research & Development team at The New York Times and is provided as-is for your own use. For more information about R&D at the Times visit rd.nytimes.com

Usage no npm install needed!