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STEP to X3D Translator

The NIST STEP to X3D Translator (STP2X3D) is an open-source software that translates a STEP (ISO 10303) Part 21 file (.stp or .step) to an X3D (ISO/IEC 19776) file (.x3d) or X3DOM file (.html). The software is based on the Open CASCADE STEP Processor and written in C++.  X3DOM files can be displayed in a web browser.

STEP, known as the “STandard for the Exchange of Product model data,” is a comprehensive information model and data exchange standard for product data through its lifecycle. X3D, which stands for “Extensible 3D Graphics,” declaratively represents 3D computer graphics.  Besides the general benefits afforded by the format, X3D offers functionality relevant for representing engineering design data, such as the CAD geometry component and the grouping component which STP2X3D uses to represent assembly structure.


STP2X3D was initially developed to visualize part geometry for the NIST STEP File Analyzer and Viewer.  All versions since STEP File Analyzer and Viewer 4.0 include STP2X3D. STP2X3D can be used standalone to translate STEP to X3D or X3DOM. This translation affords a lightweight three-dimensional (3D) model format, specifically geared for browser-based visualization.

An example model represented visually and in X3DOM code.
Credit: NIST
Sample bracket displayed in a web browser and the partial code snippet of X3DOM showing the nested structure of the model by using the Group component. Note that DEF is used to point to original components, while USE is used to describe copied components.

Users can refer to the usage guide to learn how to run the STP2X3D command-line executable with various options.  The source code is available on GitHub along with installation instructions.

Created June 29, 2020, Updated July 6, 2020