The script reads only "1" polygon.

What is the format that the Polygon are needs to be in?

Hi,
when I run a polytiles.py script for mapnik rendering. It worked just fine until the error:
http://pastebin.com/XT6kSpw7
I used '--threads 8' but with 1 thread there is still the error.
My full command:
sudo ./polytiles.py -u postgres -b 20 52 21 52 -z 17 18 -t /osm/ --threads 8 -s /openstreetmap-carto/osm.xml

subj.

Hi !

Thanks for your work !

Could you had an option "--scale X" for hdpi screen ?

Line 250: self.m.buffer_size = 128*options.scale
Line 254: mapnik.render(self.m, im, options.scale)

from https://github.com/mapnik/mapnik/wiki/XMLConfigReference :

buffer-size: Default 0; Good value is usually tile size/2 to help avoid cut labels. This influences envelope used by placement detector ( i.e. 'avoid_edges' parameter). Also set maximum-extent, otherwise you will get problems for bboxes near the borders of your map.

&

https://github.com/mapnik/mapnik/wiki/Scale-factor

Thanks :)

e.g. for ListWriter

Use mapnik.Projection instead.

subj. png8/png256/jpeg (q?)/cairo. Prepare a list of formats, or maybe just get a string and feed it to Image.save.

https://github.com/mapnik/mapnik/wiki/OutputFormats

I tried to generate mbtiles file using the following command:

polytiles.py -z 3 19 -m taxsee.mbtiles -s project.xml --host postgres-osm -d gis -u osm -a 0 --threads 4

And after ~20 seconds I've got an error:

13 5582 2497
13 5579 2497
11 1394 626
Process ThreadedWriterWrapper-1:
Traceback (most recent call last):
  File "/usr/lib/python2.7/multiprocessing/process.py", line 258, in _bootstrap
    self.run()
  File "../polytiles/polytiles.py", line 237, in run
    req, args = self.pipe.recv()
EOFError

Everything stuck then. Using --threads 1 solves the problem.
Also, issue doesn't shows up whether use plain tiles output to png files (not mbtiles).

calling the program when the optional python-psycopg2 is not installed yields

Traceback (most recent call last):
  File "polytiles.py", line 485, in <module>
    if options.bbox == None and options.poly == None and options.cities == None and options.list == None and options.area == None:
AttributeError: 'Namespace' object has no attribute 'cities'

instead, it should just display command line help.

Hi,

In directory output mode, polytiles always render tiles even if tile already exists

polytiles include in my old Mapnik sources verbose those tiles as 'exists' and skip rendering them

Regards,
Bruno.

When a tile list is specified, this is parsed with the regular expression

m = re.search(r"(\d{1,2})\D+(\d+)\D+(\d+)", line)

in line 308.However, the required order of values in the list is "x, y, z", and x can have more than the two digits allowed in this regular expression.

Either the regular expression needs to be fixed, or the file format needs to be changed to "z, x, y" (on reading and writing).

To improve rendering speed and make tiles look more like at osm.org etc., render NxN tiles at once, and split them into images.