Chris Pollett > Students > Pundi Muralidharan
[Bio] [Blog] [Deliverable 1 - WebGL Program: The Logic Behind] [Deliverable 2 - The Study of OSM Data and Vector Tiles] [Deliverable 3 - Importing OSM Data into Postgres Database] [Deliverable 4 - Study of Current Tile Generators in Trend] [CS 298 Report-Intermediate - PDF] [CS 298 - Summary of Intermediate Results - PDF] [CS 298 Project Source Code - ZIP] |
Deliverable 4 - Study of Current Tile Generators in TrendIn this deliverable, I have studied the existing tile generators and their nature of generating tiles. I have installed the following:
I have used a Windows environment here. Installing mapnik creates a few demo tiles, which gives a clue that mapnik has been setup right. After installing TileStache, it is run using the "tilestache-server.py" script, inside the scripts folder as follows: Figure: Starting Tilestache server The above implies that the server is running on localhost, on port 8080., as shown below: Figure: Tilestache server running on localhost Using the default tilestache server configuration file produces a world-tile as shown below: Figure: Default configuration produces world tile Now, using TileMill, I have attemped to create a new project. I have downloaded the osm xml files for California from http://download.geofabrik.de/north-america/us/california.html and the shape files for California roads from http://scec.usc.edu/internships/useit/content/primary-and-secondary-california-roads. The shapefile format is a popular geospatial vector data format for geographic information system (GIS) software. I have tried to add a new layer and tried to import the shape files into the TileMill project created. Adding the shape files produces desired styling effects in TileMill. After this, I have used the 'Export' option in TileMill to export the shapefiles into the desired format. I have chosen MBTiles as the chosen format as this deliverable is intended for generating tiles. Further, I have used Cygwin on Windows to install github and mbutil, which is a command line tool to generate tiles. Running the following command at the Cygwin prompt produces tiles for the shapefile imported in TileMill:
$mb-util OSM-california.mbtiles OSM-california
The following screenshot shows the tile generated: Figure: Tile Generated using TileMill for Californian Roads Upon investigating, I have concluded that using a CPU might take anywhere between 0.5 seconds to 2 minutes (tile generation for the whole world) using traditional tile generating methods. Using shader progams that run on GPUs will definitely accelerate the process of tile generation. |