In part 5 we used MSR MapCruncher to add a static tile layer to Virtual Earth. This is a very simple and straight forward approach but under some circumstances we might need to take the concept of custom tile layers a step further.
Creating Dynamic Tile-Layer from Static Images
It is possible to dynamically create a tile layer from static images. This requires a middleware which cuts the tiles on demand. On the Virtual Earth side the code is exactly the same. We are just not pointing to a virtual directory which contains static tiles but to a web service which cuts the tiles on the fly. The approach is useful if
- we have relatively small areas (e.g. 400 x 400 km)
- with frequently changing data (e.g. 20 images every 5 minutes) and
- we need to go down to the highest zoom-level but
- have a limited number of user
An example for this could be the weather-forecast. With the constraints mentioned above it would require to render 30 million tiles every 5 minutes and that this certainly beyond the capabilities of the MSR MapCruncher. Fortunately I don’t have to write that much this time since I can recycle one of my older papers. You will find the link to the documentation below:
A sample application including source code is available here.