VRML (Virtual Reality Modeling Language) was originally known before 1995 as the Virtual Reality Markup Language. It is a standard file format for representing 3-dimensional (3D) interactive vector graphics, designed particularly with the World Wide Web in mind.
VRML is a text file format where, e.g., vertices and edges for a 3D polygon can be specified along with the surface color, UV mapped textures, shininess, transparency, and so on. URLs can be associated with graphical components so that a web browser might fetch a webpage or a new VRML file from the Internet when the user clicks on the specific graphical component. Animations, sounds, lighting, and other aspects of the virtual world can interact with the user or may be triggered by external events such as timers. A special Script Node allows the addition of program code (e.g., written in Java or ECMAScript) to a VRML file.
VRML files are commonly called "worlds" and have the *.wrl extension (for example island.wrl). VRML files are in plain text and generally compress well using gzip, useful for transferring over the internet more quickly (some gzip compressed files use the *.wrz extension). Many 3D modeling programs can save objects and scenes in VRML format.
STEP or "Standard for the Exchange of Product model data" is also referred as ISO 10303. STEP has been initially designed with the idea to supersede the IGES format (which was the first broadly used vendor-neutral CAD file format). However even today both formats co-exist and data in IGES and STEP represent lion share of all CAD files.
Typically, STEP can be used to exchange data between CAD, CAM, CAE, PDM/enterprise data modeling and other CAx systems. STEP addresses product data from mechanical and electrical design, geometric dimensioning and tolerancing, analysis and manufacturing, as well as additional information specific to various industries such as automotive, aerospace, building construction, ship, oil and gas, process plants and others.
STEP is developed and maintained by the ISO technical committee. There are also various technical groups that define usage conventions and recommended practices to ensure better interoperability between software applications. In CAD world, the most prominent group is www.cax-if.org that unites software vendors and industrial users.
ISO10303 is very extremely large and complex and is structured in multiple layers, for example, from physical file format definition (Part 21) to geometrical/topological definitions (Part 42), up to Application Protocols (AP’s) defining higher-level industry use cases. CAD Exchanger supports AP203, A214 and AP242, which are most commonly used AP's.
A CAD file is an output of a CAD software, containing key information about the designed object: its geometry and topology representation, 3D model hierarchy, metadata, and visual attributes depending on the format of the file.Read more
In the seventh part of the series, we explore two open formats aimed at putting 3D data on the web, which found use in the CAD spaceRead more