root2cad

CERN ROOT geometry converter to CAD format (GLTF)

root2cad is a batch converter that can be used from pure command line (tested on linux, but should work on mac and windows).
There is also an online converter, that could be used from your browser.
Online converter,
(GitHub)

Quick start

bash



npm install -g root2cad



For drich.root that has DRICH geometry object saved to it

xvfb-run root2cad drich.root DRICH -o drich2.gltf



EIC ePIC latest full detector geometry. Look files here: 

https://eicweb.phy.anl.gov/EIC/detectors/athena/-/jobs/artifacts/master/browse/geo?job=report

xvfb-run root2cad  detector_geo_full.root Default -o detector_geo_full.gltf



Convert from gdml (CERN ROOT has to be installed)

root -e 'TGeoManager::Import("my.gdml")->Export("my.root")'

xvfb-run root2cad  my.root Default -o my.gltf



Convert to other cad formats

assimp export drich.gltf drich.obj



list file contents

xvfb-run root2cad --ls detector_geo_full.root



list geometry hierarchy

xvfb-run root2cad --ls --ls-depth=1 detector_geo_full.root Default



this will output something like

...

1    /world_volume/DRICH

...



Convert subdetector DRICH

xvfb-run root2cad detector_geo_full.root default DRICH -o drich.gltf





Installation



Prerequesties:



- One needs nodejs>13 and npm installed Installation instructions

- xvfb (X virtual framebuffer). For Ubuntu:

sudo apt-get install xvfb





NPM install



npm install -g root2cad





If npm bin paths are set correctly you should have

root2cad

 command working. 





Usage



root2cad can convert ROOT geometry objects saved in root file to GLTF format. 

The conversion works for compound and tasselated geometry.



Usage: root2cad [options] [file] [object] [volname]



Arguments:

  file         [required] File name to open (CERN ROOT files)

  object       [required] Geometry object name in ROOT file to open

  volname      [optional] Volume name in geometry hierarchy



Options:

  -o, --output   Output file name. "exported.gltf" if not set

  --ls                   Lists all objects in file or geometry (same as --ls-vol)

  --ls-vol               Lists geometry hierarchy of VOLUME names. See also --list-depth

  --ls-node              Lists geometry hierarchy of NODE names. See also --list-depth

  --ls-depth        Works with --list, defines the level to print. Default 0

  -V, --version          output the version number

  -h, --help             display help for command





Examples:

bash

For drich.root that has DRICH geometry object saved to it

xvfb-run root2cad drich.root DRICH -o drich2.gltf



List objects in file (for convenietnce)

xvfb-run root2cad  --ls drich.root



List geometry hierarchy

xvfb-run root2cad  --ls drich.root DRICH

xvfb-run root2cad  --ls --ls-depth=5 drich.root DRICH





Use GLTF VIEWER online to see the results!





$3



To convert GDML one can convert it to ROOT with this one liner:

bash

root -e 'TGeoManager::Import("drich.gdml")->Export("drich.root")'

xvfb-run node export.mjs drich.root default -o drich.gltf





During this conversion, the saved object is named 'default'

thus we use it to convert the resulting root geometry





$3



One can provide a volume name to export only this volume. So one has to specify file name, 

geometry object name inside file and volume name inside the geometry. There is

--ls

 command

that helps to see detector hierarchy and volume names.

bash

list geometry hierarchy

xvfb-run root2cad --ls --ls-depth=1 detector_geo_full.root default



this will output something like

...

1    /world_volume/DRICH

...



Convert subdetector DRICH

xvfb-run root2cad detector_geo_full.root default DRICH -o drich.gltf





Using

--ls

 and volume names could be used to automatically split DD4HEP geometry hierarchy to 

components in gftl format. See auto_split_example.py for example (files in test folder)





$3



glTF (GL Transmission Format) is a 3D file format that stores 3D model information in JSON format.

It is common for web 3d graphics but not all CAD software can work with it. Free options to 

convert from GLTF to other formats: 



- assimp (Asset Import library)

- Blender

- Microsoft 3D Builder



Assimp has a command line tool, that allows easy conversion:



Convert to other cad formats

assimp export drich.gltf drich.obj





Assimp supports many formats for export: collada, x, stp, obj, objnomtl, stl,

stlb, ply, plyb, 3ds, gltf2, glb2, gltf, glb, assbin, assxml, x3d

fbx, fbxa, 3mf, assjson



> (!) While STEP is a common format for EIC cad exchange, our experimets opening

> exported files in different CAD software shows that other formats like obj or x3d

> produce cleaner conversion and better results for complex geometry





Development



Github clone

bash



git clone --recurse-submodules https://github.com/eic/root2cad.git

cd root2cad

npm install



Running root2cad is the same as

xvfb-run node export.mjs --help    # should work







TODO



- Switch JSROOT from git submodule to npm dependency  

   (possible after the next JSroot release)

- After this it is possible to remove JSROOT depenencies we have to carry:

json

        "atob": "^2.1.2",

        "btoa": "^1.2.1",

        "canvas": "^2.9.0",

        "gl": "^5.0.0",

        "jsdom": "^19.0.0",

        "mathjax": "3.2.0",

        "xhr2": "^0.2.1",

        "zstd-codec": "^0.1.2"

``
- Convert geometry element

root2cad

CERN ROOT geometry converter to CAD format (GLTF)

Quick start

bash



npm install -g root2cad



For drich.root that has DRICH geometry object saved to it

xvfb-run root2cad drich.root DRICH -o drich2.gltf



EIC ePIC latest full detector geometry. Look files here: 

https://eicweb.phy.anl.gov/EIC/detectors/athena/-/jobs/artifacts/master/browse/geo?job=report

xvfb-run root2cad  detector_geo_full.root Default -o detector_geo_full.gltf



Convert from gdml (CERN ROOT has to be installed)

root -e 'TGeoManager::Import("my.gdml")->Export("my.root")'

xvfb-run root2cad  my.root Default -o my.gltf



Convert to other cad formats

assimp export drich.gltf drich.obj



list file contents

xvfb-run root2cad --ls detector_geo_full.root



list geometry hierarchy

xvfb-run root2cad --ls --ls-depth=1 detector_geo_full.root Default



this will output something like

...

1    /world_volume/DRICH

...



Convert subdetector DRICH

xvfb-run root2cad detector_geo_full.root default DRICH -o drich.gltf





Installation



Prerequesties:



- One needs nodejs>13 and npm installed Installation instructions

- xvfb (X virtual framebuffer). For Ubuntu:

sudo apt-get install xvfb





NPM install



npm install -g root2cad





If npm bin paths are set correctly you should have

root2cad

 command working. 





Usage



root2cad can convert ROOT geometry objects saved in root file to GLTF format. 

The conversion works for compound and tasselated geometry.



Usage: root2cad [options] [file] [object] [volname]



Arguments:

  file         [required] File name to open (CERN ROOT files)

  object       [required] Geometry object name in ROOT file to open

  volname      [optional] Volume name in geometry hierarchy



Options:

  -o, --output   Output file name. "exported.gltf" if not set

  --ls                   Lists all objects in file or geometry (same as --ls-vol)

  --ls-vol               Lists geometry hierarchy of VOLUME names. See also --list-depth

  --ls-node              Lists geometry hierarchy of NODE names. See also --list-depth

  --ls-depth        Works with --list, defines the level to print. Default 0

  -V, --version          output the version number

  -h, --help             display help for command





Examples:

bash

For drich.root that has DRICH geometry object saved to it

xvfb-run root2cad drich.root DRICH -o drich2.gltf



List objects in file (for convenietnce)

xvfb-run root2cad  --ls drich.root



List geometry hierarchy

xvfb-run root2cad  --ls drich.root DRICH

xvfb-run root2cad  --ls --ls-depth=5 drich.root DRICH





Use GLTF VIEWER online to see the results!





$3



To convert GDML one can convert it to ROOT with this one liner:

bash

root -e 'TGeoManager::Import("drich.gdml")->Export("drich.root")'

xvfb-run node export.mjs drich.root default -o drich.gltf





During this conversion, the saved object is named 'default'

thus we use it to convert the resulting root geometry





$3



One can provide a volume name to export only this volume. So one has to specify file name, 

geometry object name inside file and volume name inside the geometry. There is

--ls

 command

that helps to see detector hierarchy and volume names.

bash

list geometry hierarchy

xvfb-run root2cad --ls --ls-depth=1 detector_geo_full.root default



this will output something like

...

1    /world_volume/DRICH

...



Convert subdetector DRICH

xvfb-run root2cad detector_geo_full.root default DRICH -o drich.gltf





Using

--ls

 and volume names could be used to automatically split DD4HEP geometry hierarchy to 

components in gftl format. See auto_split_example.py for example (files in test folder)





$3



glTF (GL Transmission Format) is a 3D file format that stores 3D model information in JSON format.

It is common for web 3d graphics but not all CAD software can work with it. Free options to 

convert from GLTF to other formats: 



- assimp (Asset Import library)

- Blender

- Microsoft 3D Builder



Assimp has a command line tool, that allows easy conversion:



Convert to other cad formats

assimp export drich.gltf drich.obj





Assimp supports many formats for export: collada, x, stp, obj, objnomtl, stl,

stlb, ply, plyb, 3ds, gltf2, glb2, gltf, glb, assbin, assxml, x3d

fbx, fbxa, 3mf, assjson



> (!) While STEP is a common format for EIC cad exchange, our experimets opening

> exported files in different CAD software shows that other formats like obj or x3d

> produce cleaner conversion and better results for complex geometry





Development



Github clone

bash



git clone --recurse-submodules https://github.com/eic/root2cad.git

cd root2cad

npm install



Running root2cad is the same as

xvfb-run node export.mjs --help    # should work







TODO



- Switch JSROOT from git submodule to npm dependency  

   (possible after the next JSroot release)

- After this it is possible to remove JSROOT depenencies we have to carry:

json

        "atob": "^2.1.2",

        "btoa": "^1.2.1",

        "canvas": "^2.9.0",

        "gl": "^5.0.0",

        "jsdom": "^19.0.0",

        "mathjax": "3.2.0",

        "xhr2": "^0.2.1",

        "zstd-codec": "^0.1.2"

``
- Convert geometry element