Multipolygon and Relations

General talk
1

Hi, I’m fairly new to OSM. I am trying to learn how to effectively use Multipolygons and Relations. I have been having a hard time learning these two areas of OSM after reading and getting help from tutorials. I use JOSM with variety of plugins including the validation results. The question I have is when I create adjacent areas those areas come back with a “Area style way is not closed” then lists nodes. I cannot figure out how to fix this. I am trying to map a series of parking lot areas which are close together but with different restrictions, such as staff, motorcycle, police only, delivery.

After reading the wiki, I have tried to create a multipolygon followed by the adjacent areas which was unsuccessful. I also trial and error with relations in which I couldn’t get to comply with what I want.

I would like someones help in creating a step by step in JOSM on how to create a simple Area then attach an adjacent area onto the previous area. A brief use on how this can be used along side with Multipolygon and Relations.

I have searched and can find only help for a area within an area. Following this I would like to continue to be able to add areas adjacent areas, for an visual example like mapping parking_spaces.

Thanks

2

Just make sure the way (which is supposed to represent an area) is closed. It should begin and end at the same node.


CLOSED:

*----*
|    |
|    |
|    |
*----*

NOT CLOSED:

*----*
|
|
|
*----*

Everything should be easy for you then :slight_smile:

3

I think the first thing to do is adding information to the database. If multypolygons and relations are the right tools to do this, use them.
But for tasks for which simple polygons are sufficient; don’t use them!

Have fun.

4

As already mentioned, use simple closed ways if possible. It is okay if they share some nodes along one edge.

If you must use multipolygons, make sure that each one consists of closed rings of ways. This is visualized in the JOSM relation editor (right most column in the members section). For 2 adjacent multipolygons, this means that the common edge will be a member of both multipolygons.