This chapter shows an overview about the use and embedding of laser scan data with the open source software Potree in WebOffice 10.9 R2 SP1. Potree is licensed under the FreeBSD license (http://potree.org/wp/potree_license/).

 

 

Potree is a WebGL based viewer for large point clouds. The project evolved as a Web based viewer from the Scanopy desktop point cloud renderer by TU Wien, Institute of Computer Graphics and Algorithms. This project enables the user to present, analyze and share big 3D data sets. The extension PotreeConverter convert the 3D point clouds in a web based version and offers them within a HTML site.

 

Download

The tool for converting the 3D data sets can be downloaded via the following link:

https://github.com/potree/PotreeConverter/releases

 

System requirements

To convert the 3D data to a web based version the following system requirements have to be fulfilled to use the tool. The Visual C++ Redistributable for Visual Studio 2015 has only to be installed for the convert process of the data. If this tool is not installed it can be downloaded via the following link (https://www.microsoft.com/en-US/download/details.aspx?id=48145).

 

Installation and converting the data

The following steps have to be executed to convert the data successfully:

•Download PoTreeConverter (see above)

•Unzip the downloaded files on a suitable location (f.e. C:\Temp\Potree)

•Start command window (CMD) and execute the script to convert the laser data (example is shown below)

 

The tool supports multiplicity of options for the execution of the Potree Converter tool. These available options are shown via the following link (https://github.com/potree/PotreeConverter) within the section Use.

The following link converts 3D laser data point clouds of the XYZ format in a 3D web application format which afterwards can be embedded within WebOffice 10.9 R2 SP1.

PotreeConverter.exe C:\Temp\Potree\Daten\Land_Tirol\atlr_als_testdaten_dgm_01\dgm.xyz -o C:\Temp\Potree\converted\Land_Tirol\dgm -p tirol

 

After the execution of the tool a directory with special folder structure is created, which includes the compressed data for web based visualization. This folder must be placed directly within the IIS to get access via the web.

 

Supported formats of import data

The following 3D formats are currently supported with Potree:

•las

•laz

•binary ply

•xyz

•ptx

 

Setup within IIS (Internet Information Service)

For the setup inside the IIS the following elements have to be considered. The IIS blocks by default files without extensions. For the use of the 3D visualization they have to be explicitly allowed by the configuration of the IIS. The below listed file enables the IIS to use files without extensions which are used by Potree (binary data).

•Copy the generated folder structure (location specified by the PotreeConverter statement, f.e. C:\Temp\Potree\converted\Land_Tirol\dgm) inside the wwwroot folder of the IIS

•Create a XML file inside the main folder of the copied folder structure and name it web.config (f.e. C:\Temp\Potree\converted\Land_Tirol\dgm\web.config). The file must contain the following rows inside and save this file:

 

<?xml version="1.0" encoding="UTF-8"?>

<configuration>

    <system.webServer>

        <staticContent>

            <mimeMap fileExtension=.*" mimeType="text/xml" />

        </staticContent>

    </system.webServer>

</configuration>

 

 

Configuration

The configuration of the behavior or look of the 3D application can be done within Javascript file within the application (f.e. C:\Temp\Potree\converted\Land_Tirol\dgm\examples\tirol.js). The javascript file contains the same name as the HTML site. There the orientation of the point cloud or camera position, available tools, size of the points, view, and the maximum count of visualized points can be configured.

This settings can influence the orientation and the performance of the 3D data within the browser.

var sceneProperties = {

   path: ../resources/pointclouds/tirol/cloud.js",

   cameraPosition: null,       // other options: cameraPosition: [10,10,10],

   cameraTarget: null,         // other options: cameraTarget: [0,0,0],

   fov: 60,                   // field of view in degrees,

   sizeType: "Adaptive",   // other options: Fixed, Attenuated"

   quality: null,         // other options: Circles, Interpolation, Splats"

   material: "RGB",       // other options: Height, Intensity, Classification"

   pointLimit: 1,             // max number of points in millions

   pointSize: 1,               //

   navigation: "Orbit",       // other options: Orbit, Flight"

   useEDL: false,              

};

 

URL Call

The execution of the Potree application is done via the following URL based on the above configured name within the convert process:

http://<Server>/Land_Tirol/dom/examples/tirol.html

Linkage to WebOffice

The linkage to WebOffice is done via an external call (hyperlink) through the specific URL. In this case the layer with footprint information about the laser data was used for a WebOffice 10.9 R2 SP1 search. The linkage is based on the name of the specific object and uses the Potree application to show up in a frame window.

 

Visualization of 3D data in WebOffice 10.9 R2 SP1

The following examples show the integration of 3D laser scan data inside WebOffice 10.9 R2 SP1. The Potree application allows the user to measure single 3D point distances, change the amount of visible 3D data dynamically, choose the size of the point data.