Geometric Modeling

FDTD++ contains powerful and flexible geometric modeling capabilities.

FDTD++ contains powerful and flexible geometric modeling capabilities. It supports the import of computer-aided design (CAD) files or mesh files (e.g., tetrahedral meshes) , as well as the specification of geometries via a user-provided algorithm. The recommended approach is the former, and a variety of CAD and mesh file formats are supported. These approaches to geometric modeling are discussed below.

 


Computer-aided Design (CAD) and Mesh Support

The recommended approach to geometric modeling in FDTD++ is the import of computer-aided design (CAD) or mesh file (e.g., teterahedral meshes). Using such an approach, the creation of any geometry is possible, as well is the import of your existing geometries.

The recommended software for such modeling being the open source software SALOME1,2, as shown to the right. A number of tutorials are provided in the FDTD++ wiki that demonstrate the use of this software for geometric modeling.

A number of CAD and mesh file formats are supported, as detailed below.

 

Supported CAD Formats

  • ACIS (*.sat)
  • BREP (*.brep)
  • IGES (*.iges, *.igs)
  • STEP (*.step, *.stp)
  • STL (*.stl)
  • Any other format that can be converted to one of the above

Supported Mesh Formats

  • GMF (*.mesh, *.meshb)
  • IDEAS (*.unv)
  • MED (*.med)
  • SAUV (*.sauv)
  • STL (*.stl)
  • Any other format that can be converted to one of the above

geometric modeling with SALOME

geometry definition

Geometries Subroutine

It is also possible to model geometries in FDTD++ directly, through a user-provided subroutine that specifies material properties given (x, y, z) Cartesian coordinates2. This is often the method used in “in-house” FDTD codes (including the earlier jFDTD code), and thus a seamless transition to FDTD++ is possible. This is also useful for users who would rather provide algorithms to specify geometries, rather than utilize computer-aided design (CAD) software.

 


Notes and References

  1. SALOME is not included with FDTD++. It is open source software though, and can be obtained here.
  2. The geometries subroutine method is depreciated in the latest version of FDTD++.