Paris in 3D by Ubick

ContextCapture is becoming the standard solution for city-scale 3D mapping. It is probably the most powerful, flexible and scalable software solution to turn simple photographs into true-to-life 3D cities. It has already been chosen by leading mapping and surveying professionals like Nokia, Blom, Asia Air Survey, Airbus Group, Aerometrex and many more in Europe, America and Asia, to generate high resolution photorealistic 3D models of Paris, Tokyo, Melbourne, Stockholm… but also smaller urban areas.

Resulting from a close cooperation between the airborne surveying and mapping company InterAtlas, recently acquired by Imao, and Acute3D, over 1000 km2 of Paris have been reconstructed in true-3D, creating the most accurate virtual mockup of the most visited city in the World.

CHALLENGES

  • Automation. Mapping 1,132 km2 of Paris intramuros and its region at 7-9 cm resolution was not a reasonable project with traditional – manual – techniques. The process needed to be as automated as possible.
  • Accuracy. The objective was to reconstruct the whole area from high resolution images, in order to capture all the details of the city including the facades and vegetation.
  • Speed. The entire project had to be achieved in a reasonable time frame of a few months, since InterAtlas had already scheduled to produce dozens of urban areas with the same process, in 2013 and 2014.

SOLUTIONS

  • ContextCapture Center Edition. Built with the Center Edition with additional reconstruction engines installed on a cluster, the production unit was able to process 90+ gigapixels of input imagery every day, without any human intervention.
  • High resolution, multi-directional airborne acquisition system. In order to save flight time, InterAtlas has developed their own system to acquire very high resolution Nadir and 4-oblique imagery, to capture facades and overhangs as well as roofs, narrow streets and courtyards.

IMPACT

  • Most exhaustive and realistic reconstruction of the Paris region in 3D ever. Not thinkable with traditional techniques, the reconstruction of such a large area, at such a high resolution, was just made possible with ContextCapture.
  • Launch of the Ubick™ library. The Paris and region model was the first one available on the shelf of the Ubick™ library. Many more have joined it since this time, and InterAtlas is still working hard to make Ubick™ the best independent library for photorealistic urban 3D models in France and in Europe.
We started to acquire oblique airborne imagery in 2007, creating our own system with a local/web viewer and we are now a leader in the field of automatic 3D city modeling thanks to ContextCapture and our know-how. The Paris 2012 dataset includes 14,000 vertical photographs, 128,000 obliques, and totalizes over 6,500 gigapixels and 23TB of data! Beyond this model, InterAtlas is now generating dozens of cities and urban areas for its new Ubick™ library.
David McCartney, CTO at InterAtlas.

ACQUISITION

Acquiring tens of thousands of very high resolution aerial images (up to 210 megapixels) over an entire city, requires a real know-how.

Over the past 15 years, InterAtlas has developed a real expertise in this field, and has even conceived its own multi-directional acquisition system around Microsoft Vexcel Ultracam X/XP and Hasselblad cameras, addressing issues like storage or inertial navigation system data acquisition.

The Paris 2012 dataset includes 14,000 vertical and 128,000 oblique photographs, and totalizes over 6,500 gigapixels and 23TB of data.

PRODUCTION

After an aerial triangulation of all input photos processed by ContextCapture, the production was handled by 6 engines, installed on InterAtlas production cluster.

Due to the size of the photographs, and their number in the project, users split the project into several blocks of about 8,000 images, processed individually, and merged into the same 3D model at their respective position, thanks to the accurate georeferencing allowed by relevant ground control points.

INTEROPERABILITY

ContextCapture can export 3D models in various format, from neutral ones like OBJ, OSGB, Collada, LOD Tree, Bentley’s POD or ASPRS LAS point clouds… to native formats of several 3D GIS and visualization software solutions.

Bentley Map, Agency9 CityPlanner, Skyline TerraExplorer, Spaceyes3D and more native formats are now supported.

RETOUCHING

ContextCapture allows to control the quality of the produced model in its proprietary viewer and to select tiles containing defects (water areas or some very reflective glass buildings for instance) to export them in OBJ to third party 3D editing software for geometry and/or texture retouching.

UBICK IN THE NEWS

Watch a television report about Ubick (in French, ad before video):