How VTS fuses the data together while allowing the VTS client to handle the resources independently.

1. Server-side Data Fusion in 3D Mapping
with VTS
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Ladislav Horký, Head of Photogrammetry, Melown Technologies SE

2. Melown Tech is a software-development company
in the 3D mapping business
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3. What our software does?
I) Computer-vision and deep-learning driven reality capture
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4. What our software does?
II) 3D data fusion, virtual landscape streaming and rendering
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5. Applications
• VR and AR
• interactive simulations
• gaming
• geospatial (3D mapping)
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6. What this talk is about
I. Data fusion: Motivations and approaches
II. Data fusion in VTS
III. Demo
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7. Data Fusion:
Motivations and Approaches
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8. Motivation for the data fusion
• Display heterogeneous data together:
➔ Diferent types of data
➔ Data with diferent timestamp
➔ Data with diferent resolution
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9. Diferent types of data
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10. Data taken at diferent time
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11. Data with diferent resolution
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12. Motivation for the data fusion
• Display heterogeneous data together:
➔ To find connections and relations in the data.
➔ To watch for changes in time.
➔ To see both the details and the big picture.
• 3D can makes these relationships and changes more obvious.
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13. Common approaches to data fusion
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14. The “no fusion” approach
• Render all the together.
• Data can be independently used on the client.
• Fusion is done completely on the client.
• Very resource intensive - redundant rendering, and bandwidth.
• Not always nice result.
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15. The “fuse them all” approach
• Fusing data into one opaque structure on the server.
• Current Google maps 3D basemap.
• Suitable for Web GIS - lowest possible load on the client.
• Usually results in static data.
• Particular resources cannot be retrieved.
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16. Path to VTS
• We started with “fuse them all” approach – focus on the fast and lightweight
client.
• Maintaining large fused dataset became tedious:
➔ Fragile update operation.
➔ Including global terrain would result in unbearably large data.
• We were unable to do some things like switching the textures used on DEM.
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17. VTS action plan
• Include dynamically generated global datasets, terrain in particular.
• Improve manageability of the data on the server.
• Allow the client to work independently with the datasets.
• Maintain good client performance.
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18. What is VTS now
• An integrated platform for 3D geospatial app development.
• Opensource, BSD 2-clause license.
• Scalable, high-performance.
• Lightweight clients.
• Data fusion capabilities.
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19. What is VTS now
• Servers
➔ Mapproxy – dynamic tile generation (terrain, textures, vectors)
➔ VTSD – static content serving
• Client APIs
➔ Web – JavaScript, WebGL
➔ Desktop – C++
➔ Unity - C#
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20. Data fusion in VTS
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21. Terrain and orthophotos
• Terrain = “surface”
• Orthophotos/textures = “bound-layers”, as they need to be bound to the
surface.
• Both streamed dynamically from mapproxy based on GDAL rasters, WMS or
WMTS.
• Terrain is added to VTS storage to be fused with other surfaces in the future.
• Map configuration file describes how the bound layers will applied.
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22. Terrain and orthophotos
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{
"storage": "../stage.melown2015",
"tilesets": [ "topoearth-viewfinder6" ],
"boundLayers": {
"bmng": "/mapproxy/melown2015/tms/usgs/bmng08/boundlayer.json",
"mapy-cz": "/mapproxy/melown2015/tms/mapy-cz/mapy-cz-ophoto/boundlayer.json"
},
"view": {
"surfaces": {
"topoearth-viewfinder6": [ "bmng", "mapy-cz" ]
}
}
}

23. Terrain and orthophotos
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24. 3D models
• 3D model = “surface”
• Converted to VTS format using encoders from VEF, SLPK or LODTree.
• Fused with other surfaces when added to VTS storage:
$ vts --add storage
--tileset path/to/jenstejn-village
--top
• Modify the map configuration so the client knows about the new data.
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25. 3D models
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{
"storage": "../storage",
"tilesets": [ "jenstejn-village", "jenstejn-center", "topoearth-viewfinder6" ],
"boundLayers": { … },
"view": {
"surfaces": {
"jenstejn-village" : [],
"jenstejn-center" : [],
"topoearth-viewfinder6": [ "bmng", "mapy-cz" ]
}
}
}

26. 3D models
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27. Vectors
• Vector layer = “free-layer”, as it can be displayed on its own or in combination
with other data like surface.
• Streamed dynamically from mapproxy based on MBTiles, MVT or OGR features.
• Mapproxy enriches 2D vector data with height coordinate obtained from DEM
specified in resource definition.
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28. Vectors
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{
"storage": "../storage",
"tilesets": [ ... ],
"boundLayers": { … },
"freeLayers": {
"jenstejn-cadastre": "/mapproxy/melown2015/geodata/cuzk/jenstejn-vector-cadastre/freelayer.json"
},
"view": {
"surfaces": { … },
"freeLayers": { "jenstejn-cadastre": {} }
}
}

29. Vectors
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30. Conclusion
• Terrain and 3D (surfaces) are fused on the server. The client can still handle
them as independent data.
• Vectors (free layers) enriched with height in VTS mapproxy, displayed
independently of the other layers.
• Otrhophotos (bound layers) draped over surfaces on the client.
• VTS can go from “no fusion” to “fuse them all” as needed while preserving
advantages of both.
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31. Sources of VTS information
vtsdocs.melown.com
github.com/Melown
github.com/Melown/vts-browser-js/wiki/Examples
Getting involved in VTS development
contact: community@melown.com
or fork us on GitHub ;-)
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