What is 3D file format?

3D file formats store comprehensive details about 3D models including their attributes. Some of the formats that are popularly used include Collada, Obj, Stl, Fbx etc. The formats find wide application in diverse fields like video gaming, films, 3D printing, academic projects, engineering visualizations, architectural projections, and various scientific applications. Based on historical facts as well as ease of usage, different industries have embraced various 3D file formats. This post talks about most popular 3D file formats used in diverse industries.

Popular 3D file formats

  • STL format

    STereoLithography or STL is a universal 3D file externsion that is widely used in the segments of 3D printers, computer aided manufacturing, and rapid prototyping. The .STL file extension had been popularized by 3D Systems which originally was in the business of developing stereolithography CAD software. This STL format was developed for facilitating transfer of information related to 3D CAD modelling to 3D printers.

    With the help of an approximated triangular mesh, the 3D model’s surface geometry is encoded by STL. STL is also known by the synonyms ‘Standard Triangle Language’ or ‘Standard Tessellation Language’. This is because STL enjoys the reputation of being one of initial 3D formats that exploited tessellations for the purpose of surface geometry encoding. The scene, animated sequences and appearance of 3D models are ignored by STL. ASCII as well as binary representations, both are specified by STL format. Due to the compact nature of binary files, they are commonly used.

    In which industries it is used more?

    Rapid prototyping, 3D printing and CAM (computer aided manufacturing).

  • Obj Format

    .Obj file format primarily used for 3D printing. Approximate as well as accurate surface geometry encoding is supported by this extension. The surface mesh is not restricted to triangular facets when approximate encoding is used. Polygons can be used as quadrilaterals if the artist desires. Smooth curves along with surfaces like NURBS are used during precise encoding. Both texture and color information can be encoded by this. Material Template Library or .MTL extension is used for storing this information in a different file. Animation of any kind is not supported by Obj. Binary as well as ASCII encoding are specified by the format. ASCII encoded files are open source in nature.

    In which industries it is used more?

    3D Printing and 3D graphics.

  • FBX Format

    Primarily used in movie industry and video gaming sector, the proprietary 3D file format has been acquired by AutoDesk Inc. After its acquisition, it has been used as an interchange format by AutoDesk for its wide array of software like 3DS Max, Maya, AutoCad, Fusion 360 along with different packages.

    Model geometry as well as color, texture, and other appearance related attributes are supported by FBX. Morphs along with skeletal animations are also supported. ASCII as well binary files are extended support.

    In which industries it is used more?

    Movies’ and Video Game.

  • Collada Format

    This neutral file format is used optimally in film making and video gaming industries and its extension is .Dae.

    Geometry, animation, textures, materials, colors and other appearance related attributes are supported by the Collada file type. Due to its support for physics and kinematics, it has become a rare 3D file format which stores information with the help of XML (Extended Markup Language).

    In which industries it is used more?

    Video gaming and Film making industries.

  • 3DS Format

    This format is proprietary and natively used in the archaic Autodesk 3D Studio DOS. The popular DOS version was in due course of time substituted by 3D Studio Max. Since 1996, it is widely used in engineering, academic, production and architectural domains. It was developed in early 90s, it is considered as one of the initial file formats used for 3D modeling. Considered as the de facto industry standard for storage of information related to 3D models, 3DS format is also used to interchange with 2 different proprietary formats.

    Only the fundamental information pertaining to models’ appearance, geometry, animation and scene is retained by this file type. Surface geometry is approximately encoded with the help of a triangular mesh. The maximum number of triangles which can be used are restricted to 65536. Directional light sources are not supported by this file type. Properties related to appearance like transmissivity, texture, color, material etc. are stored. Camera position, lighting exposure and other scene related information are also stored. Information is stored in chunks after specification of a binary encoding method. This facilitates skipping of those chunks by the parsers which are not recognized.

    In which industries it is used more?

    Academic, Production, Engineering and Architectural segments.

  • IGES format

    This file type is pronounced as eye-jess. Used since many years, this format is prominently used in engineering and defense industries. The US Air Force had conceptualized this format way back in the mid 70s. During the seventies, significant amount of time used to be wasted by the Air Force for engaging in the long drawn process of data sharing and conversion for compatibility with supplier provided proprietary software. The problem used to worsen when projects of larger size such as missile delivery systems or aircraft carriers were worked upon. This is because many suppliers with their proprietary systems were dealt with.

    The US Air Force then collaborated with Boeing and other companies for developing the IGES format. This facilitated interchanging of information related to 3D CAD models across all proprietary systems. The use of IGES file format as the de facto standard for all weapons and defense related contracts was made mandatory by the US Department of Defense in 1980s. Both IGES and IGS file extensions can be used for this format.

    Surface geometry is represented with ease by this heavily flexible IGES format which uses ASCII encoding. Geometry related information is stored with the help of wireframes, accurate freeform surface architectures, CSG and circuit diagrams. Colors can also be stored by this format. However, support for material attributes such as texture and type is missing. Animation is also not supported.

    In which industries it is used more?

    Engineering and Defense industries.

  • STEP format

    STEP stands for The Standard for the Exchange for Product Data. The ISO 10303 conforming format came into existence for succeeding the IGES file format. Automobile, aeronautics, construction and other engineering related industries heavily use this file type. Both STEP and STP formats are acceptable.

    STEP was officially developed with the sole purpose of building a mechanism which can efficiently describe product data all through its life cycle without relying on any other proprietary system. The standard format initially developed suffered from size and complexity related constraints. Consequently, the format was later disintegrated into separate specification of modular nature in 4 important releases.

    All features which find support in IGES file are also supported by STEP file format. Along with this, topology, texture, material type, geometrical tolerance and other material or product related sophisticated information are encoded by STEP.

    In which industries it is used more?

    Engineering domains like aeronautics, automobile, construction etc.

  • VRML and X3D formats

    VRML is pronounced as vermal. It has the file extension of .WRL. It is an abbreviation of Virtual Reality Modeling Language. This was initially developed to support the world wide web. Later, VRML was substituted by X3D file format. The format has not been widely adopted by major software makers. This may be due to the fact that VRML extension failed to keep pace with the rapid advances of 3D graphics in real time. Finally, the name of the VRML consortium had been changed to the Web3D Consortium. In 2001, the next generation file format of VRML was launched with the X3D extension.

    X3D stands for XML based 3D file type. Entire array of features supported by VRML file format finds support in X3D format. Also, certain additional features are supported by X3D. A polygonal mesh is used by the VRML format for encoding surface geometry. Information related to appearance like color, transparency, texture etc. can be stored. With X3D, information related to scene is stored. Animation is supported. Surface geometry can also encode NURBS.

    In which industry it is used more?

    Internet or world wide web industry.

Conclusion

By now, you must have gained significant insights into the various 3D file formats widely used. Knowledge of these formats is important to work in agile manner in 3D modeling, video gaming, movie production, architectural visualization, 3D printing, construction, special effects, engineering and other industries. If you want to know more about them, you may get in touch with our 3D experts for more clarification regarding this.

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