[Tilesathome] lowzoom rendering takes forever?

[spaetz]

On Sat, Nov 24, 2007 at 12:18:57PM +1100, Brent Easton wrote:

> I believe there is nothing wrong, that's just the way the new lowzoom works. 
> The amount of data downloaded in a z8 tile can be huge for areas around well mapped cities. 

As the guy who initially did the "new lowzoom" I would like to comment on the situation. It was an experiment as I was annoyed by unreadable text at low zoom levels and want to play with Etienne's osmxapi. However given the scaling problems we see, I am convinced that this is the wrong approach and should be turned off until we have something feasable.

I only see 2 solutions:
1) Implement a simplification preprocessor that cuts down the OSM files to a manageable complexity (no need for a 1m resolution when you squeeze half of the UK on a tile).

2) Render a z12 which is geared for lowzoom generation, ie without text and just with the major roads etc. Then stitch them together for lowzoom tiles and overlay them with a transparent text layer. To make IE happy, we would probably merge down both layers in one PNG file.

I don't have the time or motivation at the moment to implement either solution, but this is what I think would make osmarender lowzoom work.

spaetz