The rasterizing plug-in enables the conversion of vector data (coordinate-based geometry definitions) to raster data (images). It allows to extend the vector layer rendering pipeline by introducing an extra rasterizing step. The vector tile response will thereby contain an URL content-type that allows the client to fetch the tile as a normal image.
From a visualization view point, rasterizing tiles are quite comparable to vector tiles for many use cases such as panning and zooming. They have significant advantages when the amount of vector data is high, either in terms of features or in the amount of coordinates for each feature. Especially for web clients, DOM-based vector rendering (SVG/VML) is quite slow and should not be used beyond a couple of thousand features (state of the art as of beginning 2011). In this case rasterizing provides a significant performance boost, especially when combined with server-side caching of the image tiles.
On the other hand, there are some use cases which are evidently difficult to treat without vectorial information at hand:
- editing of geometries.
- snapping to other layers.
- selection of features.
Geomajas provides the ability to load vector data on demand in such cases, thereby combining the best of both worlds.
Community & Docs
Using this project in maven
<dependency> <groupId>org.geomajas.plugin</groupId> <artifactId>geomajas-server-plugin-rasterizing-parent</artifactId> <version>1.17.0</version> </dependency>