3D Geometries

Last Modified: 11/07/99

Lighting for 3D Worlds VRML also also permits substantial control over lighting in the form of: Point lights where the light emanates from a single point that speads out. Spotlights which produce a cone of light in a specific direction Directional lights in the form of parallel rays that come from a certain direction. You can control many properties of these lights, such as their color, intensity, direction, attenuation, radius, and cutoff angle. Most of these controls are done with a mouse acting on "light manipulators" These look like large balls with a vertical cylinder stuffed thru them and have arrows and other projections that you can control. It takes some time to get used to their manipulations. Here is an example of these controls for a spotlight where I have inserted a light manipulator that looks like a red ball with a white cylinder thru it. You see a large arrow which shows the direction of the light and a red mesh cone that shows the spread of the light. You can manipulate the light in many ways: click on the red ball and you can move the light source in 3D; click on the mesh cone and you can make it narrow or broad; click on the arrow (front or back) and you can swivel it in any direction. Non-VRML 3D systems allow some additional controls, such as "gels" (textures associated with lights), and softer edges.				Class Topics What Can VRML Do? 3D Geometries 3D Surface Properties Lighting for 3D Worlds Environments for 3D Worlds Viewing 3D Worlds Animation and Sound Utilities and File Structure VRML by Hand or Program The Future of 3D for the Web

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Lighting for 3D Worlds