Putting the map into OSM: rendering geo-data with Mapnik Artem Pavlenko mapnik.org

A brief history of (web)mapping Good old 70 s GIS OGC – WMS, WFS, W*S ... Google Maps [???]

Good old 70 s GIS

OGC – WMS, WFS, W*S ...

Google Maps

[???]

Why did I like Google Maps? No Java, no Flash, no ActiveX No W*S Lots of data Good looking maps APIs

No Java, no Flash, no ActiveX

No W*S

Lots of data

Good looking maps

APIs

What was the problem, then? It is not free! Data is subject to license and rendering software is proprietary

It is not free!

Data is subject to license and rendering software is proprietary

Searching for the solution In the post GMap world we expect web mapping to be: Fast Highly interactive And to have good cartography At the time, none of the FOSS tools delivered these...

In the post GMap world we expect web mapping to be:

Fast

Highly interactive

And to have good cartography

Mapnik

Mapnik is not ... GIS A map server, though you can hack one with Mapnik in no time Attempt to implement all OGC specs in Java and bully the rest for not doing so MapNick – I'm not Nick ...

GIS

A map server, though you can hack one with Mapnik in no time

Attempt to implement all OGC specs in Java and bully the rest for not doing so

MapNick – I'm not Nick ...

Mapnik is ... About making beautiful maps What I wanted to use myself F/OSS Cross platform – Linux, Mac OS X, Win32 Written in modern c++ Easy to get started (Python bindings) Flexible design

About making beautiful maps

What I wanted to use myself

F/OSS

Cross platform – Linux, Mac OS X, Win32

Written in modern c++

Easy to get started (Python bindings)

Flexible design

How do you make a map?

Making a map is easy from mapnik import * m = Map(800,600) load_map(m,'/Users/artem/map.xml') m.zoom_to_box(Envelope(-180,-90,180,90)) render_to_file(m,"world.jpg","jpeg") What is *.xml?

from mapnik import *

m = Map(800,600)

load_map(m,'/Users/artem/map.xml')

m.zoom_to_box(Envelope(-180,-90,180,90))

render_to_file(m,"world.jpg","jpeg")

What is *.xml?

Making a map is easy <Map bgcolor='steelblue'> </Map>

<Map bgcolor='steelblue'>

</Map>

Making a map is easy <Map bgcolor='steelblue'> <Layer name='mylayer'> <Datasource type='shape' file='/tmp/world'/> </Layer> </Map>

<Map bgcolor='steelblue'>

<Layer name='mylayer'>

<Datasource type='shape' file='/tmp/world'/>

</Layer>

</Map>

Making a map is easy (almost) <Map bgcolor='steelblue'> <Style name='My Style'> <Rule> <PolygonSymbolizer> <CssParameter name='fill'>lightgrey</CssParameter> </PolygonSymbolizer> <LineSymbolizer> <CssParameter name='stroke'>white</CssParameter> </LineSymbolizer> </Rule> </Style> <Layer name='countries'> <Style>MyStyle</Style> <Datasource type='shape' file='/tmp/shapefile/world' /> </Layer> </Map>

<Map bgcolor='steelblue'>

<Style name='My Style'>

<Rule>

<PolygonSymbolizer>

<CssParameter name='fill'>lightgrey</CssParameter>

</PolygonSymbolizer>

<LineSymbolizer>

<CssParameter name='stroke'>white</CssParameter>

</LineSymbolizer>

</Rule>

</Style>

<Layer name='countries'>

<Style>MyStyle</Style>

<Datasource type='shape' file='/tmp/shapefile/world' />

</Layer>

</Map>

Making a map is fun f rom mapnik import * m = Map(800,600,&quot;+proj=latlong +datum=WGS84&quot;) m.background = Color('steelblue') s = Style() r=Rule() r.symbols.append(PolygonSymbolizer(Color('#f2eff9'))) r.symbols.append(LineSymbolizer(Color('rgb(50%,50%,50%)'),0.1)) s.rules.append(r) m.append_style('My Style') lyr = Layer('world') lyr.datasource Shapefile(file='/opt/data/countries') lyr.styles.append('My Style') m.layers.append(lyr) m.zoom_to_box(lyr.envelope()) render_to_file(m,'world.jpg', 'jpeg')

f rom mapnik import *

m = Map(800,600,&quot;+proj=latlong +datum=WGS84&quot;)

m.background = Color('steelblue')

s = Style()

r=Rule()

r.symbols.append(PolygonSymbolizer(Color('#f2eff9')))

r.symbols.append(LineSymbolizer(Color('rgb(50%,50%,50%)'),0.1))

s.rules.append(r)

m.append_style('My Style')

lyr = Layer('world')

lyr.datasource Shapefile(file='/opt/data/countries')

lyr.styles.append('My Style')

m.layers.append(lyr)

m.zoom_to_box(lyr.envelope())

render_to_file(m,'world.jpg', 'jpeg')

Made it!

More about styling... Named styles, each layer can have 0...N style(s) Order is important – 'painter model' 0...N Styles -> 0...N Rules ->(Min/Max Scale Denominator, Filter, 0...N Symbolizer(s)) Filter is 'filter expression'

Named styles, each layer can have 0...N style(s)

Order is important – 'painter model'

0...N Styles -> 0...N Rules ->(Min/Max Scale Denominator, Filter, 0...N Symbolizer(s))

Filter is 'filter expression'

Filter expressions - DSEL Syntax for filter expressions is very simple, you enclose variables (evaluated at runtime) in square brackets - [var] Arithmetics: + , - , * , / Comparison: = , <> , > , < , >= ,<= Logical operators: and, or , not regular expressions: [attribute].match('your_reg_ex')

Syntax for filter expressions is very simple, you enclose variables (evaluated at runtime) in square brackets - [var]

Arithmetics: + , - , * , /

Comparison: = , <> , > , < , >= ,<=

Logical operators: and, or , not

regular expressions: [attribute].match('your_reg_ex')

Filter expressions - examples [highway] = 'motorway' or 'motorway_link' = [highway] [cfcc].match('^A1[0-9]') [area] > 1000 and [area] <= (1000*2)

[highway] = 'motorway' or 'motorway_link' = [highway]

[cfcc].match('^A1[0-9]')

[area] > 1000 and [area] <= (1000*2)

Making an OpenStreetMap Challenges and opportunities

Challenges and opportunities

The first challenge Data entered by real people uclassified uhclassified unc lassified unclasiffied unclasified unclassfied unclassiefied unclassifed unclassifeid unclassiffied unclassified unclassified unclessified uncliassified undefined ... 'horse' = 'yes' 'village_green'

Data entered by real people

uclassified uhclassified unc lassified unclasiffied unclasified unclassfied unclassiefied unclassifed unclassifeid unclassiffied unclassified unclassified unclessified uncliassified undefined ...

'horse' = 'yes'

'village_green'

Facing the challenge Data processing : compile raw OSM data into domain specific formats suited for rendering, routing, small devices etc. We have some tools already: osm2pgsql, osm2shp, osm2kml, osm2whatever but we'll need more.

Data processing : compile raw OSM data into domain specific formats suited for rendering, routing, small devices etc.

We have some tools already: osm2pgsql, osm2shp, osm2kml, osm2whatever but we'll need more.

osm2pgsql $ osm2pgsql planet.osm.bz2 Outputs 'clean' geometries Builds polygons Assigns z-order ~30 minutes on my laptop planet.osm -> osm2pgsql -> postgresql/postgis

$ osm2pgsql planet.osm.bz2

Outputs 'clean' geometries

Builds polygons

Assigns z-order

~30 minutes on my laptop

planet.osm -> osm2pgsql -> postgresql/postgis

More challenges Visualising 'live' data Users want reward for their efforts: “ where is my track on the map? I want it now!”

Visualising 'live' data

Users want reward for their efforts: “ where is my track on the map? I want it now!”

Possible solutions Mapnik at home? Planet.diff? Direct rendering from live OSM database?

Mapnik at home?

Planet.diff?

Direct rendering from live OSM database?

Tiles. How many? Level 1 - 4 tiles Level 2 - 16 tiles Level 18 - 68719476736 tiles :( Let user decide - 3244998 tiles :) More resources will be needed very soon!

Level 1 - 4 tiles

Level 2 - 16 tiles

Level 18 - 68719476736 tiles :(

Let user decide - 3244998 tiles :)

More resources will be needed very soon!

Yet another challenge! Or do I mean opportunity... Number of map features will continue to grow... (osm.)XML sucks! What is the answer?

Number of map features will continue to grow...

(osm.)XML sucks!

What is the answer?

Map editor? OSM Illustrator?

An opportunity for Mapnik OSM style community scrutiny and effort are invaluable Mapnik is FREE and everyone can get involved To play with some new features grab the ISO image from: http:// artem.dev.openstreetmap.org/files/osm-linux.iso

OSM style community scrutiny and effort are invaluable

Mapnik is FREE and everyone can get involved

To play with some new features grab the ISO image from: http:// artem.dev.openstreetmap.org/files/osm-linux.iso

A future history of (web)mapping? Good old 70 s GIS OGC – WMS, WFS, W*S Google Maps [OpenStreetMap]

Good old 70 s GIS

OGC – WMS, WFS, W*S

Google Maps

[OpenStreetMap]

Thank you!