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Home > Supported File Formats > 3D Studio to Universal Scene Description


How to convert 3D Studio (.3ds) 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.

     

3D Studio

The .3ds file format was the native file format of the old Autodesk '3D Studio R1-R4' software, which was popular up to about 1996 before its successor (3ds Max) replaced it. The file format is a dated, 16-bit, obsolete format. It is limited to triangle geometry, 65536 polygons per mesh, no vertex normals for accurate smoothing, 8.3 DOS filename naming and a maximum of 10 characters for object names.

Please do not confuse the .3ds format with the 3ds Max .max format. You will find throughout the 3D industry that some companies refer to .3ds as the "3ds Max file format" but this is not true. The native file format of 3ds Max is the .max format, whereas .3ds is just a legacy import/export file format ported over to 3ds Max by Tom Hudson during the transition from 3D Studio R4 back in the early 1990s. DO NOT use the .3ds file format to convert to/from 3ds Max but rather use Okino's dedicated PolyTrans-for-3dsMax plug-in system for 3ds Max.

     

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