Skip to content
Extract spline geometries from Rhino/OpenNURBS files
C++ CMake
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.
.github Update issue templates (#5) Apr 14, 2019
src Update to-do list for add trimming curves to the surfaces Apr 21, 2019
LICENSE Update LICENSE Apr 19, 2019 Add uninstall target Nov 22, 2018

RW3DM - Rhino Extensions for NURBS-Python (geomdl)

Build status

RW3DM project provides executables for exporting and importing OpenNURBS/Rhino .3DM files in JSON format. It utilizes OpenNURBS library for reading and writing .3DM files and JsonCpp for importing and exporting geomdl geometry data.

Installation and Updating RW3DM

Downloading RW3DM

You can download the precompiled binaries under Releases.

Compiling RW3DM

If you prefer to compile the binaries on your own, you can follow the following list as a reference:

  1. Clone the repository: git clone
  2. Change to the directory of the local repository: cd rw3dm
  3. Update submodules: git submodule update --init
  4. Create a build directory for CMake-generated files, e.g. mkdir build
  5. Enter the build directory, e.g. cd build
  6. Run CMake to generate build configuration files, e.g. cmake .. or use CMake GUI
  7. Compile and install
  • For Windows, you will find the Visual Studio project files under build directory.
  • After opening Visual Studio, choose Release from the build combobox, then right click on INSTALL and choose Rebuild
  • For Linux, run make install inside the build directory
  • The install directory will be build/install by default
  • You can modify the install directory using RW3DM_INSTALL_DIR variable while configuring the project with CMake
  1. Go to the install directory, e.g. cd install or the one you configured with CMake during step 6
  2. You will find the executables inside the install directory

Updating RW3DM

If you prefer to update the compiled binaries on your own, you can follow the following list as a reference:

  1. Pull the latest commits: git pull --rebase
  2. Update submodules: git submodule update
  3. Repeat steps from 5 to 9

Notes on installing and updating

For Windows

  • Visual Studio 2017 is required to compile OpenNURBS
  • Please install C++ support on Visual Studio as it is not installed by default
  • Choose Release as the build configuration inside Visual Studio before you compile the package

For Linux

  • It is tested with gcc 7.3 and it should be compatible with any gcc version supporting C++17
  • Please remember to install the compiler packages for your Linux distribution

Using RW3DM

Reading .3DM files

on2json executable can be used to convert .3DM files to JSON format supported by geomdl. The JSON files can be imported via geomdl's exchange.import_json API call.

Writing .3DM files

json2on executable can be used to convert JSON format supported by geomdl to .3DM files. The JSON files can be exported via geomdl's exchange.export_json API call.

Available arguments

Run on2json and json2on to see the available command-line arguments:

  • extract_curves: Extract curves (Default is extract surfaces)
  • normalize: Normalize knot vectors and scale trim curves to [0,1] domain
  • sense: Extract surface and trim curve direction w.r.t. the face
  • show_config: Print the configuration
  • silent: Disable all printed messages
  • trims: Extract trim curves

Example: on2json MyONFile.3dm extract_curves=True, extracts curves from MyONFile.3dm



You can’t perform that action at this time.