Importing predefined CAD models into GEANT4 is not always possible or requires intermediate file format conversion to Geometry Description Markup Language (GDML) using commercial or third party software. CADMesh is a direct CAD model import interface for GEANT4 optionally leveraging VCGLIB, and ASSIMP by default. Currently it supports the import of triangular facet surface meshes defined in formats such as STL and PLY. A G4TessellatedSolid is returned and can be included in a standard user detector constructor. You can find the project page and a Mercurial repository here.
Additional functionality is included for the fast navigation of tessellated solids by automatically creating equivalent tetrahedral meshes thereby making smart voxelisation available for the solid.
CADMesh is described in a technical paper, available here. If you would like the cite the article, you may wish use the following bibtex entry:
@article{poole2012acad,
author = {Poole, C. M. and Cornelius, I. and Trapp, J. V. and Langton, C. M.},
title = {{A CAD Interface for GEANT4}},
journal={Australasian Physical & Engineering Science in Medicine},
year = 2012,
month = September,
doi = {10.1007/s13246-012-0159-8},
url = {http://www.springerlink.com/content/u563877422284578}
}
The fast tessellated solid navigation technique included in CADMesh is described here:
@article{poole2012fast,
title={Fast Tessellated Solid Navigation in GEANT4},
author={Poole, C. and Cornelius, I. and Trapp, J. and Langton, C.M.},
journal={IEEE Transactions on Nuclear Science},
volume={99},
pages={1--7},
year={2012},
publisher={Institute of Electrical and Electronics Engineers}
}
#Example Usage The following shows basic default usage for cadmesh in a UserDetectorConstruction:
// User Detector Constructor
#include "CADMesh.hh"
...
G4ThreeVector offset;
G4VSolid * cad_solid;
G4LogicalVolume * cad_logical;
G4VPhysicalVolume * cad_physical;
...
offset = G4ThreeVector(-30*cm, 0, 0);
CADMesh * mesh = new CADMesh("../../models/cone.ply", mm, offset, false);
cad_solid = mesh->TessellatedMesh();
cad_logical = new G4LogicalVolume(cad_solid, water, "cad_logical", 0, 0, 0);
cad_physical = new G4PVPlacement(0, G4ThreeVector(), cad_logical,
"cad_physical", world_logical, false, 0);
...
# CMakeLists.txt
cmake_minimum_required(VERSION 2.6 FATAL_ERROR)
project(cadmesh_example)
# GEANT4 core
find_package(Geant4 REQUIRED ui_all vis_all)
include(${Geant4_USE_FILE})
include_directories(${PROJECT_SOURCE_DIR}/include)
# CADMesh
find_package(cadmesh)
# User code
file(GLOB sources ${PROJECT_SOURCE_DIR}/src/*.cc)
file(GLOB headers ${PROJECT_SOURCE_DIR}/include/*.hh)
add_executable(cadmesh_example cadmesh_example.cc ${sources} ${headers})
target_link_libraries(cadmesh_example ${Geant4_LIBRARIES})
target_link_libraries(cadmesh_example ${cadmesh_LIBRARIES})
A working installation of the folowing libraries or packages is required:
- GEANT4 (4.9.6)
- ASSIMP (default, optional with VCGLIB)
sudo apt-get install libassimp-dev
- VCGLIB (optional)
- TETGEN1.4.3 (optional)
- QT and OpenGL (for COLLADA support using VCGLIB)
For installation of v0.5 and below see the wikipage OldInstallation. For the old gmake installation method see GMakeInstallation. Now we use cmake!
Download the latest release of CADMesh from the Downloads section, and extract the archive, or checkout the development branch from the repository.
Additionally, download VCGLIB (you can find more information about acquiring VCGLIB here) and download tetgen from here (on ubuntu you can sudo apt-get install libtet1.4.2-dev
).
# Checkout VCGLIB (optional)
# svn co https://vcg.svn.sourceforge.net/svnroot/vcg/trunk/vcglib vcglib -r 4041
# CADMesh latest dev branch
git clone https://github.com/christopherpoole/CADMesh.git
cd CADMesh/
mkdir build
cd build
# Default (using ASSIMP)
cmake ..
# OR for fast tessellated solids with tetgen
cmake .. -DWITH_TETGEN="ON"
# For CAD using VCGLIB
cmake .. -DWITH_VCGLIB="ON" -DVCGLIB_DIR="/path/to/vcglib"
# FOR TET only
cmake .. -DWITH_ASSIMP="OFF" -DWITHVCGLIB="OFF" -DWITH_TETGEN="ON"
make
sudo make install
Here is a basic example usage. The CMakeLists.txt file illustrates how to link against CADMesh.
# Run example (Linux with g++)
cd examples/basic
mkdir build
cd build
cmake ..
make
cd ..
./build/cadmesh_example
Idle> exit