Geometry updates

Jan Marsch • 2018-01-31

We've rolled out an update to geometry handling that is long overdue.

It seemed impossible to cover all cases of OpenStreetMap geometry tagging. Even if you are close - a new exception pops up. There are a lot of guidelines but nobody is forced to follow them.

Server side

We are doing a lot of tag aligning server side. But for geometry, building polygons from a collection of lines never worked properly. It's not a trivial task because lines might not be ordered, disconnected, crossing, pointing in different directions etc.

While this tagging schema is rarely used everywhere it seems common in Russia.

Another change is calculation of roof direction on server side. If it has not been tagged then this step helps rendering gabled and round roofs. Side note: for skillion roofs there would be no safe solution and hipped roofs will require complex geometry.

Client side

Now roofDirection is set on more buildings and properly rendered. Also roofOrientation (across/along) is respected on server side and thus not provided anymore. A few roof / geometry combinations are skipped now because there were too many artifacts.

Onion roofs got new nicer shape, overall color saturation got decreased by about 30%.

What do you think? Let us know