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How to convert Universal Scene Description (.usd,.usda, .usdc.usdz) to DWG (AutoCAD, DXF)?

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

DWG

DXF and DWG are the native file formats of the Autodesk AutoCAD product since 1982. DWG is the binary file variation to the ASCII DXF file format. These files can be viewed by many programs including Autodesk's free DWG TrueView application. It is a closed file format but has been documented by the Open Design Alliance.

At Okino we consider DXF/DWG to be one of the worst 3D file formats when translating 3D model data between applications (depending on its contents). There is very little understanding about this in the 3D graphics world. As outlined in our "CAD Data Sourcing Suggestons and Rules" page you should ideally use the DWF-3D file format when sourcing from either AutoCAD, Navisworks, Revit and optionally Autodesk Inventor.

Due to deep history, Autodesk software can embed ACIS SAT "BREP solids" data in some of its DXF/DWG files. This is the ideal case as the "BREP solids" geometry definitions lead to cleaner and higher fidelity MCAD file conversions. But even so, it would generally be a safer bet to use a STEP AP214 or "IGES BREP solids" file in such cases.

Universal Scene Description import converter's overview

DWG export converter's overview