[MapProxy] zoom levels and resolution

[Oliver Tonnhofer]

On 01.10.2012, at 05:45, André Pirard wrote:
> I was using a cache that, without any res configuration created folders 16, 17, 18 and 19 which I relate to zoom levels.
> To follow your method, I used
>   debug_source:
>      type: debug
> This painted the following first 2 numbers, roughly at the indicated meters/JOSM scale (2.5 screen cm).
> I suggest you write them to standard output (instead or in addition).
> I have absolutely no idea what calculation produces those numbers.
> I assumed they correspond to the former 19 and 18, I continued multiplying by 2 and I got:
> 19:   0.29858214: 4, 11,  22, 
> 18:   0.59716428: 63
> 17:   1.19432856
> 16:   2.38865712
> 15:   4.77731424
> 14:   9.55462848
> 13: 19.10925696
> 12: 38.21851392
> 11: 76.43702784
> 
> I chose to use:
> res: [76.43702784, 19.10925696, 4.77731424, 1.19432856, 0.29858214]
> 
> Now I surprised to find directories 4 and 3 instead of 19 and 17.
> Why?  It would have been simple.

Because you told MapProxy to do so :)
You configured a grid with 5 levels, from level 0 at resolution 76.43702784 to level 4 at resolution 0.29858214.


> Q5: is there anything to read on the Web that would help answering not only Q1-Q4 but also Q6-Q∞? :-)

The question is: What are you trying to do and what did not work with your first configuration (without res)?


Regards,
Oliver

-- 
Oliver Tonnhofer    | Omniscale GmbH & Co KG    | http://omniscale.de
http://mapproxy.org | https://github.com/olt    | @oltonn