Does anyone know if there is an open source project in Java that will take a set of (x, y, z) points and create a contour map for Google Maps/Earth?
There does not seem to be a good contouring application for Google Maps. Any suggestions?
JAI-Tools (http://code.google.com/p/jai-tools/) has a contour operation. I'm not sure if it will handle point input or requires a raster DEM.
GDAL has a Java API available at http://gdal.org/java/ To use it, you would probably need to create a raster file with gdal_grid and then create the contours with gdal_contour. I don't think you will be able to create a proper triangulated irregular network (TIN) directly from the points, but the dem may be accurate enough for your needs.
If someone still looking for this question, I have created open Java project for the contours, the input data from the coordinate value (double X, double Y, Integer VALUE). In the project there are tests. On top Delaunay triangulation be built on them, and the line is built with the same value. There are additional methods (reduction in size and multiplying the number of triangles for smoothness and flatness, approximation, extracting polygons for maps). Very fast. Now I need to add an algorithm for constructing contour taking into account the fault lines. link to bitbucket