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Home > Supported File Formats > FBX to Universal Scene Description


How to convert FBX (FilmBox v5/v6/v7,.fbx) to Universal Scene Description (.usd,.usda, .usdc.usdz)?


PolyTrans|CAD+DCC performs mathematically precise CAD, DCC/Animation, GIS and BIM 3D file conversions into all key downstream 3D packages and file formats. Okino software is used and trusted throughout the world by many tens of thousands of 3D professionals in mission & production critical environments, backed by respectable personal support directly from our core development team.

     

FBX

FBX is a 3D 'digital asset interchange' file format that had been pushed on the 3D industry by Autodesk after they acquired it from the bankruptcy assets of its prior owners, Alias Research and Kaydara of Canada. FBX has its placed in the DCC/Animation world but it does have its limitations, given that it is a closed and proprietary file format of Autodesk.

Note: if you are one of the many people who use FBX to convert data out of Navisworks, Revit, AutoCAD or Inventor then please use DWF-3D file format and Okino's DWF-3D import converter instead. It is a night and day difference but little known except to our core Okino users. Likewise, use our native program support for 3ds Max, Maya and Cinema-4D rather than use FBX.

FBX supports all the common attributes of a DCC/Animation file format such as mesh geometry with vertex normals and vertex colors, non-solids NURBS ('old school NURBS'), lights, cameras, hierarchy, bones and mesh skinning (deformations), materials and textures. In basic terms, it is similar to the capabilities of the COLLADA and VRML2/X3D file formats, and to Okino's long standard BDF data translation file format.

Okino has a very long history associated with FBX as it created the very first and fully implemented set of FBX import and export converters in 2002, with full animation, skinning and trimmed NURBS support. This was long before anyone had much heard of FBX. And to this very day we are still the only company that actively ships and supports FBX v5 (Kaydara), v6 (Alias) and v7 (Autodesk). However, FBX was just one of many 'not invented here' file formats which came to glut the 3D market in the 2005-2007 era, many of which petered away over time.

A key reason for its early adoption, throughout the 3D industry, was the availability of a free and officially supported (but closed) FBX SDK from Autodesk.

The downsides of the FBX file format is that (1) it has stagnated in recent years, (2) it is based on a legacy material model and not on modern PBR, (3) it is based on legacy lighting models and not on physically based lighting, and (4) it is a closed file format which only Autodesk can update or change. Otherwise, these restrictions have made it easier for software developers to implement FBX just once and then not have to worry about costly yearly revisions.

     

Universal Scene Description

The USD format (“Universal Scene Description”) is an open 3D model and scene format designed for efficient storage and streaming of 3D asset data. It is a high-performance extensible framework and ecosystem for describing, composing, simulating, and collaboratively navigating and constructing 3D scenes. An extensive overview of USD is provided in the Okino USD documentation.

Pixar Animation Studios originally created the USD platform (as its fourth generation variation after its Marionette & Preso systems) to improve studio-wide collaborative workflows. USD provides a concept of "scene composition", building a unified scene from potentially thousands of loosely-coupled source assets. For example, the mesh, rigging, materials, and animation for a single model might all come from different "layers" (files), each created and maintained by a different artist or department. Layers can store multiple "variants" of any given data, helping to solve problems of versioning/approval. The coupling between layers is very dynamic and loose, allowing for greater flexibility during the production process. The entire USD system is designed to facilitate a large studio making feature films, with all of the scale that that implies.

USD should be considered more of a code framework (“OpenUSD”) for use in group collaboration, to help with the aggregation of various 3D data sources into a unified scene through a process referred to as scene composition. A subset of that code framework provides for reading and writing USD disk-based files as well as rendering USD scenes (Hydra). The system is rather complex to implement (for software developers) and to use (from first principles) as a 3D graphics artist. The USD file format itself is not for faint of heart and is best read/written using the OpenUSD SDK + various programming APIs. More commonly used ASCII 3D file formats such as COLLADA, VRML2 and Wavefront OBJ are much easier to manipulate/understand/use on a human level basis.

File extensions used by the standard include:

  • .usd, Either ASCII or binary-encoded
  • .usda, ASCII encoded
  • .usdc, Binary encoded
  • .usdz, Zero-compression, unencrypted zip file