OS Model Builder – Create Accurate 3D Models in Minutes

By David Crowther

In May 2015 I undertook a project for the Landscape Architects – terra firma – to help provide 3D mapping analysis for a planning application in Woking. The project utilised the 3D Modelling application – Infraworks - from Autodesk. As this was the first time I had used an Autodesk product there was a lot I had to learn in order to ensure I could successfully take OS data, site surveys, and additional GIS datasets and create an accurate 3D Model in Infraworks. My Case Study on the Woking Infraworks Model can be accessed here – http://www.dynamicmaps.co.uk/2015/05/29/infraworks-360-bim-in-action-terra-firma-woking-borough-council/

Infraworks has an inbuilt Model Builder tool that will allow you to select a geographic area and automatically build a 3D Model. The Model Builder utilises Roads and Railway data from OpenStreetMap and Aerial Imagery and Terrain DEM’s direct from Bing:

While the inbuilt Infraworks Model Builder provides quick access to data and builds a Model for you, unfortunately the coverage and overall accuracy of this free data can often be a drawback. Two examples of this include; the OpenStreetMap building coverage is quite sparse when compared to OS MasterMap, in the example below left the housing estate to the east of the Ordnance Survey office has not yet been digitised within OpenStreetMap. Also the 30m Terrain DEM appears very inaccurate when compared to OS Terrain5, in the example below right the 30m Terrain shows the runway at Heathrow as being rather more bumpy that I expect it is.

It was clear that the Model Builder data was not going to be accurate enough for the analysis that the client wanted to undertake, especially as building height attributes were integral to the project, and without that information the Model would not be considered as part of a the planning application process. As a result we decided to utilise OS datasets in order to create a 3D Model from scratch that had the accuracy that we needed.

This is where my learning curve took a steep incline!.., although my skills in documenting complex work flows came in very handy. So much so that I created a 50-page document which described the end 2 end process from ordering OS datasets to their final configuration within Infraworks. One example of this process was how to get OS MasterMap building polygons into an accurate 3D Model.

While the final 3D Model was worth the wait, with the accuracy of the OS data ensuring that the Model was well received by the client, the end 2 end process of ordering the OS data, translating it from source formats, clipping to an area of extents and then configuring it within Infraworks would mean that only highly trained GIS/CAD operatives can generate these types of accurate 3D Models.

“The major benefit of working with Cadline and the OS on the I360 model is that we are able to generate accurate visualisations from any viewpoint.” Robyn Butcher, Associate Director, The terra firma Consultancy.

As a team we thought that there must be a better way to provide Infraworks users with access to accurate datasets from the Ordnance Survey in a pre-configured ready to use 3D Model. That application is the OS Model Builder.

Cadline and Ordnance Survey are partnering to offer the Ordnance Survey Model Builder for professionals such as architects and engineers which will provide a single CAD-ready file of detailed maps and data to help them produce detailed 3D and 2D designs early in the planning phase. The OS Model Builder can be accessed via a URL using any internet browser and is also mobile compatible, which means you can order and build your 3D Models while in the field.

The Interface is simple to use allowing you to find your geographic location, draw an Area of Interest and then choose to order OS MasterMap Buildings (with height attributes), OS Imagery and OS Terrain 5, with the added option to order OS Open Rivers and OS Open Roads.

Having chosen your area and datasets the application then automatically emails you with a link to download your 3D Model. You then simply open your Model into Infraworks, refresh the data sources, zoom to your chosen Model location and the 3D Model is pre-configured and clipped to the correct extents for you. There are no complex data processing tasks, translation of datasets from one format to another and once you have opened your Model you can then simply add extra datasets as you wish, for instance environmental, utilities and transport layers.

The OS Model Builder has just completed Beta Testing (April 2016) and our beta testers gave the following feedback:

• Saves time connecting to and configuring multiple data sources.
• Build Models faster than current process.
• Overall a great tool for collecting data for your model.
• Already recommended to practically everyone in the office.
• I think that the model builder is a great tool for a small or private sector engineering consultancy.
• Very easy to use and requires little knowledge of connecting to and configuring data sources.
• One stop shop for OS Data. An easy way to see the upfront cost of OS pricing.

Having been through the collective pain of ordering, downloading, translating, processing and then configuring OS data to create a 3D Model in Infraworks, I know that I would certainly have benefited from this tool at the start of the terra firma project.

Why not try the OS Model Builder Application yourself: OS Model Builder