One of the unique aspects of the Great Trails approach is the multi-level and detailed nature of the model. As previously mentioned we have planned three levels Overview, Explore and Experience. Overview is intended to be a rich digital version of the Physical 3D Models that were traditionally exhibited in Tourist Information Centres and Museums. The Explore level is more akin to a Model Village where you can effectively walk on the model to get the “Sense of Place” and with Experience you can disappear down the Rabbit Hole to access an unlimited range of possible options (more about that in future posts).
From a modelling perspective the Explore Level raises challenges related to the level of detail that needs to be represented. Paths can no longer be simple dotted lines and additional features such as buildings, trees, fences, walls and rivers need to be modelled to a reasonable level of detail. Even with the extensive capabilities of modern Games Engines It would be impractical to model all this information manually and thus integration to suitable data sources and automatic creation of entities is required.
We are fortunate that the Lake District is very well represented in Open Street Map (OSM) and location data for all of the entities mentioned above may be exported for a certain area. Using some custom “plug-ins” it is then possible to automatically convert this information into suitable 3D representations.
For example OSM data for the area around the Helvellyn Youth Hostel and Greenside Mine is shown below.
And the corresponding rendering of this data in the Explore Level of the Great Trails model is as follows.
It should be stressed that this process is not 100% automatic, however the bulk of the model creation is through the integration and automation. There is also a lot of control over what is imported as every entity in OSM has a unique identifier allowing for information to be transferred in stages. Thus, for example, if a particular fence is to be imported it may be accessed by it’s ID and imported as the correct type of fence. This approach was used for the wooden fence in the picture above.
Buildings are mostly represented by cubes which give the overall proportions and relative position. In most cases these are replaced by models manually prepared in a 3D modelling package but the OSM data is still invaluable in creating realistic and correctly located building models.
A rough estimate is that ~70% of the Explore level creation is automated, compared to ~85% in the case of the Overview level. It should be possible to streamline the process and improve on this in the future. The benefit of the Games Engine technology is that the model can be edited after the data import to add entities not present in the OSM data and to generally enhance. It is expected this will be an ongoing process as more information becomes available.
Initial indications are that this method of creating the Explore Level provides a realistic representation and feel of the area in question.