Notes on delivering

Interactive 3D Worlds via the Internet

Written by Paul Bourke
December 1995


The problem of presenting interactive 3D environments to a user over the internet is for the most part a tradeoff between bandwidth and processing power. The goal is to create a highly realistic rendition of the 3D environment at the same time giving the viewer the ability to interact with the environment. Interaction can be at many levels from just being able to move around and view the environment, being able to modify and add to the geometry, being able to change material and lighting, being able to interact with other users within the 3D space.

There are two prevalent approaches being pursued on the internet today each with an emphasis on either realism or interaction. The first is the VRML approach where a description of the environment is transfered to viewing software on the users personal computer. After this transfer is complete the interaction of the viewer within the 3D world and the rendering of the views is done locally.

The other approach is to render the current environment remotely and transmit the resulting image to the user. Subsequent interaction (generally movement) is sent to the remote rendering machine/server for processing.

The advantages and disadvantages of these two approaches as well as some other methods will be discussed below.

Local "VRML" model

Advantages Disadvantages

Remote server model

Advantages

Disadvantages

Other solutions

Precomputed environments Hybrid Server-Client processing