Water surface	Shallow water	Deeper water

High water clarity	Medium water clarity	Low water clarity

Deep sea illumination	Patch bounding boxes	Mesh detail levels

The purpose of this work is to create a real-time visual simulation of the undersea environment. The project uses the Maverik VR kernel for scene management and interaction, together with Mesa / OpenGL to provide graphical effects. The scene is displayed at over 20 frames per second on a 350 MHz PC with 3Dfx Voodoo2 graphics support.

There is also a slightly out-of-date MPEG movie (4.1 Mb) of this work available.
 

 Features implemented:

• Sky model. Implemented using a texture mapped hemisphere, centred above the viewer's eye position.

 
• Water surface. Modelled using a translucent polygon with an animated texture applied.

 
• Seabed. Created using John Beale's hf-lab height field generator. Seabed patches are represented using triangle strips with a rough texture map. Level-of-detail management is implemented so that more distant patches contain fewer triangles.

 
• Particles. A particle system is used to represent fine debris suspended within the sea. Brownian motion is applied to each particle to simulate random drift.

 
• Caustic light effects. The seabed colour is modulated using an animated texture. The intensity of this lessens as the sea depth is increased.

 
• OpenGL lighting model. The ambient illumination changes with undersea depth making the particles and seabed darken as the viewer descends. The user may turn on spotlights which illuminate the local region in front of the viewer's eye point.

 
• Water clarity. This may be adjusted to simulate different levels of visibility.

 
• User interaction. The scene may be explored using the mouse. Keyboard commands are used to modify the scene properties (sea depth, fog density etc).

 
• Collision detection. The user is prevented from passing through solid objects in the scene.

• Light glare effects. Undersea spotlights create visible glare trails in the water.

 
• Air bubbles. Streams of environment-mapped bubbles may be generated within the scene.