[OSM-talk] Visualizing relations, was: Change in OSM Inspector License View/WTFE

[ant]

Hi,

On 01.02.2012 18:05, Frederik Ramm wrote:
> Finally, I am looking at ways to visualize relations on the OSMI view.
> If you have any ideas about that, feel free to suggest something.

I've been thinking about this and I believe that visualizing relations 
in terms of making them actually visible on a map is a really 
challenging task. What I've seen so far is Merkaartor's way of drawing 
bounding boxes around a relation's members, and JOSM's highlighting with 
some colour (also seen on various maps showing routes). The former, 
however, clutters the map on small scales, and the latter in principle 
works for a very limited number of relations only. So basically you want 
to make sure that
- relation symbols are placed at representative locations,
- relation symbols don't occlude neither nodes or ways nor each other,
- the set of visible relations meaningfully relates to the map scale,
- the view doesn't get cluttered.

I have some immature ideas about how to go about it, but for the purpose 
of OSMI I think you should prefer the quick and dirty way ;)

Display a list of relation IDs as plain text (or name tag instead, if 
given) coloured according to the licence status. In order to keep the 
list short, define upper and lower bounds for the maximum Euclidean 
distance between two relation members in each zoom level. For ways 
simply use the coordinates of the first node, for relations use those of 
the first member.

cheers
ant