Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg

OpenStreetMap3DChallenges and Technology of a Virtual Globe Model

Arne Schilling

GIScience,

Department of Geography,

University of Heidelberg

OGC TC Meeting Toulouse, 09/22/2010

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 2 / 16

OpenStreetMap3D

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 3 / 16

OpenStreetMap3D

Goals1. create and visualize a global landscape and city model based on

OpenStreetMap. 2. find out how a Web 3D Service (W3DS) can be combined with a

virtual globe model

http://w3ds.orghttp://osm-3d.org

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 4 / 16

OpenStreetMap3D

Technical issues1. Precision problem2. Scene graph transformations3. LOD implementation

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 5 / 16

Precision Problem

Single precision matrixcalculations may cause jitter

Solved by movingModelView calculation tosoftware

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 6 / 16

Scenegraph Transformations

Data as received from W3DS in Map Projection CRS (Spherical Mercator)

Data as displayed in the final application in Cartesian Coordinates

x

y

z

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 7 / 16

Scenegraph Transformations

World origin

Transform

Shape in local Coordinates

Tile center

Scene Graph Model used in X3D - Concept

Example

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 8 / 16

Scenegraph Transformations

Map origin

Transform

Shape in local Coordinates

Tile center

World origin = earth center

Transform

Shape in local Coordinates

Tile center

Spherical Mercator (Map Projection)

Cartesian Coordinates (Globe)

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 9 / 16

Scenegraph Transformations

Procedure1. Local to world transform matrix2. Apply actual coordinate reference transformation3. Reconstruct the original structure

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 10 / 16

Scenegraph Transformations

Distortions due to mapprojection

No projection

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 11 / 16

Tiles loaded into client

LOD Implementation

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 12 / 16

Terrain model has multiple levels

Objects are loaded at the base levels

Top level tile

Base level tiles

LOD Implementation

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 13 / 16

LOD Implementation

1. Distance to Tile

2. Normal to viewpoint angleα

3. View direction to object angle

β

NV

C

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 14 / 16

Database

2.4 million buildings5.6 million point objects150 GB in total

Work on Europe 3D in progressWill be > 1 TB in size

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 15 / 16

Map Functions

Routing

POI Search

Arne Schilling, GIScience, Department of GeographyUniversity of Heidelberg11/16/2010 16 / 16

The End

Thank You

Any Questions?