Grid Exemplars: Web mapping in 3D. - Mark Morrison

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1 Grid Exemplars: Web mapping in 3D - Mark Morrison

2 Fractal Technologies Fractal Technologies are software solution providers to E&M Focus on improving access to and use of (3D) spatial data Long standing collaboration with CSIRO particularly DEM Successful commercialisation of research outcomes FracViewer FracSIS FracWormer

3 Fractal Technologies are a key collaborator in Glass Earth Provide custom extensions to FracSIS as required through in-house team dedicated to the project An example of CSIRO and industry working effectively together for the benefit of both Fractal are also a primary sponsor of XMML project, which forms a core component of the SEEGrid infrastructure Provide both XMML import and XMML export capability as a standard component of FracSIS This presentation outlines some of the work carried out under the Glass Earth agreement

4 3D Geoscience over the web Examples of 3D web applications Communication data and interpretations e.g. global exploration company ( 3D Maps ) Public access to 3D information (visual) Data provision e.g. Geological surveys Technical applications (data processing) 3D WebGIS

5 3D Geoscience over the web Architectures Web does not necessarily just mean browsers Browser-based Low-end generic client (e.g. public access) Low cost to client Server-side processing for thin client Familiar interface, ubiquitous Web service aware applications Applications that use the web for accessing data and processing services Specialised programs for technical users where performance is critical Can have hybrids where plugins are hosted in a web browser

6 3D Mapping on the web Fractal and Glass Earth have built a demonstrator to enable a web browser to view 3D models (Solid Earth, not just flat maps) Primarily to prove that XMML and WFS technologies can be successfully applied to provide web access to (views of) 3D geospatial data Exposes FracSIS database to other non-fractal applications through WFS Built to work with current industry norms for web connections

7 The FracSIS/Glass Earth Prototype Utilise open standards-based technologies to extend FracSIS visualisation to the web Serve data in FracSIS databases to remote processing services

8 Requirements Make models available using freely available client technologies (browser + plugins) Minimise security issues (firewalls, etc) use http Capability to connect to variety of back-end data stores User should be unaware they are connected to a FracSIS database Simple manipulation tools on client Visibility Object colour Translation, scale, rotation Potential to access to underlying data for an object in open format (XMML)

9 Implementation Utilise WFS as the way to communicate with web server to get data and visualisation Separation of back-end storage from presentation FracSIS Relational databases GIS Tables Raw data files Ability to change back-end storage and provide new data types without requiring new client application to be shipped Standard means of requesting data in well-known format Our version is very minimal (GetFeature( GetFeature) Use XMML as the interchange format for data Style sheets utilised on client for varying presentation of data as HTML

10 Implementation (2) Visual representation of data uses VRML Availability of browser plugins Natural mapping to FracSIS scene files Some capability to use scripting in browser to provide limited user interaction Top level navigation to 3D Maps provided through existing FracSIS scene files User views can be pre-built to provide a catalog Scene files can be constructed dynamically Scene files provide separation of data and visual representations Appropriate level of detail for browsing Give user a choice of low or high detail Automate this based on connection speed References to FracSIS objects gives live models

11 Architecture Cache Scene2VRML Scene Files FracSIS API FracSIS database Web Server WFS CGI XMML Translation Browser Javascript VRML plugin

12 Demonstration FracSIS WFS Web viewer

13 User is initially presented with a set of FracSIS scenes

14 User clicks on a scene and receives 3D view (VRML)

15 HTML controls allow simple editing ability (e.g. fault is now red)

16 Layer control enables objects to be hidden/shown

17 Extension to Data Provision Feature request in WFS specifies an ENCODING of return value For viewing, we used VRML as the encoding type Change encoding to XMML and WFS returns raw data for an object We also implemented summary encoding This allows the same WFS to become a visual navigation front-end for data provision Could also use meta-data or other information to query for objects Return data as XMML Use style sheets to convert to other formats Demonstration

18 User requests XMML data for Zoe fault object

19 Another WebMapComposer Plug

20 Some Issues Bandwidth on commercial broadband Need to separate data from visual representation Provide appropriate detail in views Information security Visualisation useful, but only graphics Raw data valuable, may want to protect Thin v Fat clients Not many thin clients capable of 3D visualisation Visualisation capability of client General graphics plugins (VRML, X3D, etc) Availability Limits potential functionality (e.g. volume visualisation) Specialised clients and plugins Provision of views on client side Other visualisation tools Perhaps required for technical applications

21 Concluding remarks This work is a simple demonstrator Shows that WFS is a useful way to abstract data sources from data consumers Provided a good test-bed for XMML implementation Shows that it is viable to consider using 3D maps in a web environment A version built for the SEEGrid would make use of other web services and provide visualisation capabilities to web service consumers.