[PSUBS-MAILIST] FYI: VARKON - A Parametric CAD-tool - FREE

["Steven Mills" <barycenter@earthlink.net>]

Haven't tried this yet.  Some of you might find a use for it.

It's *free*

 http://www.tech.oru.se/cad/varkon/

--Steve



What is Varkon ?
VARKON can be used as a traditional CAD-system with drafting, modelling and visualization if you want to but the real power of VARKON is in parametric modelling and CAD applications development. VARKON includes interactive parametric modelling in 2D or 3D but also the unique MBS programming language integrated in the graphical environment. 
The system was originally developed by a group at the University of Linkoping in Sweden during 1984-86 under the leadership of Dr. Johan Kjellander who was then the president of Microform AB. From 1986 the system was owned, marketed and further developed by Microform AB. The sourcecode of VARKON is now maintained by the CAD research group at the Department of Technology at Örebro University in Sweden. 

VARKON is written in ANSI portable C and has been compiled and successfully executed on many different platforms. The UNIX version has a user interface based on X-Windows and the PC version uses Microsoft WIN32. Currently there are VARKON systems running on workstations from HP, SUN, IBM and SiliconGraphics and also systems on VAX's with VMS or Intel PC's with SCO/UNIX, GNU/Linux or Windows95/98/NT. There is even a customer  running Varkon on a Cray T3E supercomputer with 256  300Mhz 64 bit Alpha processors ! 

VARKON is free software. The UNIX version is distributed in sourcecode under the GNU/GPL license. There is also a prebuilt binary version for GNU/Linux free of charge. Check the download pages for instructions on how to obtain the software. 
  
  

Some things you can do with VARKON.
VARKON is used to develop and run applications. An application is a VARKON system that's been modified and extended with knowledge and functionality specific to a certain product or problem. VARKON applications can perform any calculations, retrieve data from external databases, make decisions, perform complex geometrical operations, build object oriented structures with attributes and geometry, generate graphic images like 2D drawings or 3D models with shading or hidden lines removed and create any type of datafiles with output of your own choice. 
VARKON is ideally suited for all types of variational design. Wooden houses, tools for ballbearings, welded steel parts or electrical installations are some of the products currently designed in VARKON using this technique. 

In variational design the actual design work is often reduced to a few percent of the time spent with traditional methods. Using VARKON with its unique ability to handle geometry as well as other features and store the result in a well structured and object oriented manner it is also easy to produce much more information than paper drawings. Cost estimations, bill of materials and different forms of manufacturing data are usually created automatically in VARKON applications. 

VARKON is easy to integrate. A VARKON application can communicate using files or pipes and can spawn other processes as well as being spawned itself. Using this technique you can either let a VARKON application be on top and control other systems or you can use other systems to control VARKON. The Windows95/NT version of the system also includes an ODBC API for communication with commersial databases. 

VARKON is a powerful geometric modeller. Basic 3D entities are points, lines, arcs, curves, surfaces, coordinate systems and transformations. Several representations of parametric curves are implemented including rational polynomial, analytical offset and curves on surfaces so called UV-curves. Surface representations include rational polynomial, lofted procedural, analytical offset and a faceted surface for approximations. Operations include intersects, closest point, silhouette, curvatures, transformation, trimming, export, import and approximation. Basic visualization as well as complex rendering based on OpenGL is included in all versions of the system. 

A key feature in all modeling is the capability to record not only the results of interactive operations but also the operations themselves, making it possible to go back and inspect what you have done, then change something and automatically update the model. Being a fully generic system this is standard behavior in VARKON. All interactive operations are automatically recorded as MBS-statements and the model can any time be edited using the MBS-editor instead of interactive graphics if this is preferred. Using MBS your own design rules or constraints can easily be linked into the model. Such changes are automatically compiled and the result shown immediately on the screen. 
  
  

Two things you can't do.
VARKON is not a true solid modeller. VARKON surfaces can be faceted and images can be produced with shading or hidden lines removed but mass properties like volume or center of gravity can not be calculated automatically. This doesn't mean you cant use VARKON in applications where weight or volume is important. It only means you will have to deal with the problem in other (maybe less automatic) ways. 
VARKON is not a manufacturing (CAM) system. There are no high level functions in VARKON to support the programming of multi axis numerical machines. You can create your geometry in VARKON but multi axis machine programming will have to be done using other software. For less complicated manufacturing processes though it can surprisingly often be worth the effort to let VARKON applications generate numerical control data automatically even if this means extra programming in MBS initially.