Chapter 17.   Picking the Models

This chapter continues using the 3D world of chapter 16, but as a setting to demonstrate four new coding techniques:

• the loading and positioning of 3D models created using the Wavefront OBJ file format;
   
• the selection (picking) of objects in the scene by clicking on them with the mouse;
   
• 3D sound, in this case the chirping of a penguin, which varies as the user moves around the scene (nearer and further from a penguin model). It's implemented using JOAL and my JOALSoundMan class introduced in chapter 13;
   
• fog shrouding the scene, making it harder to find the models.

The screenshots on the right show the TourModelsGL application without the fog, and with it. The four OBJ models are a penguin (a mesh wrapped in a single texture), a couch (employing a single red material), a rose in a vase with several different colors, and a racing car decorated with several colors and textures.

TourModelsGL reuses the checkerboard floor from the previous chapter, but I've removed the skybox, billboard trees, the rotating sphere, the splash screen and the game over message in order to simplify the code.

I'll start this chapter by describing the OBJ format and the key elements of my OBJLoader package, and illustrate its use in a simple model viewer, ModelLoaderGL (shown on the right).

The model's name is specified on the command line, along with the display size and whether the model should be rotated.

Downloads

• The PDF file for the chapter (235 KB). Last updated: 3rd January 2007.
  
• Zipped Source code (505 KB). Last updated: 12th February 2007.
  I updated the code to use new features in JSR 231 RC 2.
  

• Up to the Pro Java 6 3D Game Development Index Page
• Back to Chapter 16. Touring the World
• On to JOGL Chapter 4. Stereo Viewing