I think I’ve talked about this on forums, but the actual blog post I meant to write (months ago) has been sitting in my ‘drafts’ folder and it’s so obsolete that I’m just going to start again. So…
As you may have heard, X-Plane 10 is going to use OpenStreetMap (OSM) as our data source for vector road data and some fraction of our vector water-body data. X-Plane 9 uses TIGER and VMAP0, so switching to OSM will be a huge improvement.
If you haven’t looked at OSM, the very short version is that it’s a cross between Google Maps and Wikipedia: it’s a global map of vector data that anyone can edit. And unlike Google Maps, anyone can get the actual vector data and use it for any purpose. This makes OSM useful for creating global scenery.
Here is a comparison of downtown Paris in VMAP0 and OSM.
(That’s the 48N 2E tile, which contains Paris. The top images are a whole-tile and metro image from VMAP0, and the bottom are the same areas in OSM.)
There are two big wins with OSM:
- OSM contains significantly better road data in every part of the world. In the US, we had a complete road grid via TIGER, but OSM has been improved to contain direction-of-travel and bridge information. This extra information allows us to construct a much more plausible road system. In Europe the win is incomparable: we are going from having virtually no vector data to having the complete road grid of many major European cities.
- More importantly, OSM provides all of the infrastructure to improve the data. You can directly edit OSM either on your own machine (via JOSM) or directly in your web browser (via Potlatch). OSM has the infrastructure to accept changes, track changes, and the management infrastructure to view history, revert mistakes, and accept many edits from a huge user base simultaneously. Their servers to accept edits are already running and maintained.
I can’t emphasize the importance of this second point enough. In the eight years since I first started poking my nose into X-Plane scenery, I have heard this more times than I can count: “The lake near my house is in the wrong place. Can I fix it and send you the fix”?
Until now the answer has been: no. The lake comes from a data set and when we recut the scenery, any user edits would be destroyed by the conversion from source data. OSM changes that. OSM is the source data, so if you improve global data within OSM, you have fixed the problem permanently.
Not only does OSM make it easy to fix problems permanently, but OSM makes it easy to make very small changes. This morning I was viewing my own town and discovered that two railroad bridges were not marked. I clicked the edit tab, marked out the bridges, and saved my change. You can start with a single edit.
By connecting X-Plane’s source data to the OpenStreetMap community, we can join forces with many other communities that are all working to improve the availability of global mapping data; our improvements (for the sake of improving X-Plane) can help other groups that are working on completely different projects, and their improvements benefit us.
In future posts I will address some of the details of what data we are using, how you can contribute in ways that will affect the global scenery, and how we are (trying) to cope with the OSM licensing change. But I want to make one point immediately:
Just because the global scenery will use OSM does not mean that global scenery will be the only way to use OSM. There are already several existing projects (e.g. XPOSM and OSM2XP) that will build custom scenery from OSM data. OSM provides a rich and detailed geodatabase; the global scenery is only beginning to scratch the surface of what can be done with the data. So I do not see our use of OSM as making some of the other OSM/X-Plane projects obsolete.
For example, OSM2XP utilizes OSM building data, which we will not be using in the version 10 global scenery. I think that the more tools we have to use OSM data, the better, as they give authors more choice in creating scenery.