Chapter 27.   Terrain Generation with Terragen

A significant drawback of the FractalLand3D example from the last chapter is the programmer's lack of control over the generated terrain. Most games require mountains, fields, lakes, and so on, to be in fixed, specific places, rather than randomly located each time the program starts.

A theme of earlier chapters is the use of external modeling software to create complex-looking scenery, artifacts, and figures. The same argument applies to terrain building -- there are many excellent tools far more suited to the task than a DIY approach coded in Java.

We will use Terragen, a popular scenery generation package. The landscape is designed with Terragen, then exported as a OBJ file (representing the landscape as a mesh), and as a BMP (showing the surface viewed from above). The BMP is subsequently edited and converted into a JPG.

Our Terra3D application loads the OBJ and JPG files, using the JPG as a texture to cover the Shape3D created from the landscape mesh. The images on this page two landscapes, originally designed with Terragen, then loaded by Terra3D.

The pictures show some of the other elements of Terra3D:

• the landscape can be decorated with two types of scenery: 3D models loaded with our PropManager class, and 2D ground cover images (e.g. the trees, sagebrush) which always stay oriented towards the viewer;
• the ground cover objects utilize SharedGroup nodes so that only a single instance of a shape is created by Java 3D;
• the edges of the landscape are surrounded by walls covered in a mountain range image;
• the sky is filled with stars (an approach suggested by Kevin Duling);
• picking is again employed for terrain following (as in Chapter 26), but the implementation is complicated by a need to deal with large landscapes. A consequence is that a viewer can walk 'inside' a mountain, but will eventually be repositioned on its surface.

Downloads

• The PDF file for the draft chapter (the old ch.17.5) (754 KB). Last updated: 19th August 2003.
  
• Zipped Source code (200 KB).
  (Includes two examples but not NCSA Portfolio, or the OBJ files for the landscapes). Last updated: 19th April 2005. The book's code.
  
• Zipped OBJ files for: test1.obj (1.05MB), test2.obj (1.05MB). Last updated: 19th August 2003.
  
• NCSA Portfolio (zipped) (402 KB).
  

• Up to the Killer Game Programming in Java Index Page
• Back to Chapter 26. Fractal Land
• On to Chapter 28. Trees that Grow