STEP X3D Translation
STEP to X3D Translation
Methods for converting STEP (ISO 10303) exchange files to X3D files. Here we focus on direct translation; an alternative method will be to read import a STEP file into a full featured CAD program and then export either as X3D if avallable or export as VRML, then perform a VRML -> X3D translation.
CADExchanger is a commercial product available for Windows and Mac OS that offers import and export for a number of formats . At version 3.12 It offers import (and export) for STEP files and export for X3D. Conversion is by importing a STEP file and exporting as X3D. The developers also offer command-line products for bulk conversion, a software development kit, and development services.
Open Cascade and PythonOCC
Open Casade is an open source (LGPL) geometry kernel written in C++. PythonOCC is a Python binding to the function exposed in compiled OpenCascade libraries, and so allows OpenCascade functions to be called from Python scripts. A simple Python script calling STEP import function followed by X3D export of the model:
# Python script simplified from the example script # core_load_step_ap203_to_x3d distributed with pythonOCC input_file = 'm12_2.stp' # input STEP (AP203/AP214 file) output_file = 'm12_2.x3d' # output X3D file from OCC.STEPControl import STEPControl_Reader from OCC.IFSelect import IFSelect_RetDone, IFSelect_ItemsByEntity from OCC.Visualization import Tesselator, atNormal step_reader = STEPControl_Reader() status = step_reader.ReadFile( input_file ) if status == IFSelect_RetDone: # check status failsonly = False step_reader.PrintCheckLoad(failsonly, IFSelect_ItemsByEntity) step_reader.PrintCheckTransfer(failsonly, IFSelect_ItemsByEntity) aResShape = step_reader.Shape(1) else: print("Error: can't read file.") sys.exit(0) Tesselator(aResShape).ExportShapeToX3D( output_file )
SPRI is a web application that allows browsing the content of STEP files. A STEP file can contain multiple geometric models and the web application allows for viewing what models are available in a file and selecting which are translated to X3C content. Preparing an X3D model requires these steps:
- Using the FORM element on the upload page, choose a local STEP file and submit it to the server.
- The page displayed on a successful upload will offer options for information views of the STEP file. The "assemblies" view is the most direct way to retrieve X3D translations.
- On the assemblies page choose which assembly to render.
- The rendering page will present an X3DOM view and also have links to download an X3D file and to view the X3D model with the Cobweb browser.