Bl
Bl
Bl
Bl
Bl
You are here:   Home »  Products »  PolyTrans|CAD+DCC  
Bl

Home > Supported File Formats > Universal Scene Description to DWF


How to convert Universal Scene Description (.usd,.usda, .usdc.usdz) to DWF (DWFx)?


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.

     

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

     

DWF

Okino knows of the DWF file format very well as we have been involved with its evolution since the year 2000. A DWF file is nothing other than a renamed "ZIP" file which contains other internal assets such as a HOOPS HSF 3D model file and several XML files used to describe meta data and other aspects of the model. You can rename the .dwf file to .zip and then open it in any ZIP handling software.

The HSF file format was created by Ithaca Software in the mid 1980's as an efficient, light weight, compressed 3D visualization format. Thereafter it was adapted and adopted by Tech Soft 3D in the early 2000s for use by Autodesk as a "3D variation" of its prior 2D-vector-centric DWF file format (and hence how HSF became DWF). DWF/HSF is considered a "polygonal mesh" file format and not a NURBS/solids MCAD file format.

DWF attained acceptable traction after 2006 when Autodesk made it a primary conduit to export high quality 3D visualization data from its main CAD products such as AutoCAD, Navisworks, Revit and Inventor. Okino considers DWF as one of its most important non-MCAD file formats to bring in very large 3D models (such as massive oil & gas rigs, 3D plants and refineries) from these 4 aforementioned Autodesk products as well as from AVEVA PDMS software.