I'm trying to draw a map using OSM raw data.Some of buildings have holes inside (may even more than one hole at a time) .
In way list, all I can see is set of "way nodes". Where should I get the information in OSM.xml that a Node represent a hole is belong to a specific building?
Note: In Relation there is innerWay - outerWay relation for some buildings but it does not cover all the cases as I see. How openstreetmap draw building?
I achieved drawing it in Opengl using tesselation without knowing which hole belong which building but, I couldn't apply same approach on unity. Here is a screenshot from opengl :