A number software tools exist to assist in the task of reducing polygons (both for creating levels of detail and simply to turn a huge model exported fra a CAD system into a model with a number of polygons that the target system can cope with in real time). Some 3D modelling system (e.g. Inspire 3D) have this kind of functionality built in.

A typical 'low-end' polygon reduction tool is Chisel from Trapezium software.

A typical 'high-end' polygon reduction tool is Rational Reducer from Systems in Motion AS.

The big difference between Chisel and RR is that RR enables you to visualise what you are doing as you do it, enabling you to adjust parameters and see the result immediately. Chisel uses simpler algorithms and requires much more trial and error in order to get good results.

Chisel, however, does lots of others things that make it a very useful tool for VRML developers. In fact, the polygon reduction tools can be viewed as a little bonus. Chisel's additional features include:

• Syntax checking
• Formatting
• Cleaning (e.g. removing default, unused or repeated values)
• Condensing (e.g. adjusting numerical resultion, removing normals, removing unused DEFs, creating PROTOs, creating DEF/USE)
• Reorganisation (e.g. inlining shapes, uninlining inlines, spliting indexed face sets)

A number of these things are also available using combinations of freeware tools (see, for example, the tools section of the VRML Works or MacWeb3D web sites)