====== Set-theoretic operations with R-functions ======
{{frep:truecsg4.gif?nolink}} = {{frep:truecsg1.gif?nolink}} & {{frep:truecsg2.gif?nolink}} & {{frep:truecsg3.gif?nolink}}

We use R-functions to represent a CSG object by a single real function. Well-known min/max functions are only C0 continuous. This can cause unpredictable results in further operations on the object. Other R-functions can provide C1 and even Ck continuity of the resulting function. It helped to formulate analytical descriptions for such operations as blending, offsetting, sweeping and others.

{{frep:stul1_100.gif}} [[http://hyperfun.org/stul1.gif|Click]] to get a more large image of a CSG chair

Details on set-theoretic and many other operations with R-functions can be found in the paper:

Pasko A.A., Adzhiev V.D., Sourin A.I., Savchenko V.V. "Function representation in geometric modeling: concepts, implementation and applications", The Visual Computer, vol.11, No.8, 1995, pp.429-446.\\
Electronic version: [[http://hyperfun.org/F-rep.ps|PostScript (467K)]] and [[http://hyperfun.org/F-rep.ps.gz|PostScript + gzip (112K)]]