Jonathan Bronson
Scientific Computing & Imaging Institute
University of Utah
Project page: http://www.sci.utah.edu/cleaver
Mailing list: [email protected]
Contact: [email protected]
The Cleaver Library is based on the 'Lattice Cleaving' algorithm:
Bronson J., Levine, J., Whitaker R., "Lattice Cleaving: Conforming Tetrahedral Meshes of Multimaterial Domains with Bounded Quality". Proceedings of the 21st International Meshing Roundtable (San Jose, CA, Oct 7-10, 2012)
The method is theoretically guaranteed to produce valid meshes with bounded dihedral angles, while still conforming to multi-material material surfaces. Empirically these bounds have been shown ot be significant.
The Cleaver Library is written in C++. It is designed to be cross-platform and has been successfully compiled on Windows 7, Mac OSx, and Linux. Binary forms will be available on the Cleaver project page.
cmake [src]
make
Alternatively, if you do not wish to build the command line program (which requires the Teem Library) use ccmake to disable it.
What Can Cleaver Do?
Cleaver generates conforming tetrahedral meshes for multimaterial or multiphase volumetric data. Both geometric accuracy and element quality are bounded. The method is a stencil-based approach, and relies on an octree structure to provide a coarse level of grading in regions of homogeneity.
What does Cleaver use as input?
The cleaving algorithm works by utilizing indicator functions. These functions indicate the strength or relative presence of a particular material. At each point, only the material with the largest indicator value is considered present. In practice, inside- outside and distance functions are most common.
What is the input format?
The cleaver library takes as input an instance of the Cleaver::Volume class. The Volume is a collection of Cleaver::ScalarField's, along with a sampling rate. The Cleaver::ScalarField class is an abstract class, that can be extended by users to create arbitrary inputs. We provide the FloatField class for loading 3D arrays of floating point data. The Cleaver command-line tool also offers convenience functions for loading the teem NRRD image format into the FloatField format.
What is the output format?
The Cleaver Library returns a Cleaver::TetMesh object.
This object supports direct output to file in several formats:
1. TetGen: .node, .ele
2. SCIRun: .pts, .elem, .txt
3. Matlab: .mat
Some geometric operations in this code do not yet use proper predicates, and are therefore not guaranteed safe for all possible input fields. This is something we will work towards fixing in later releases. In the mean time, if you have data that you unable to mesh with Cleaver, contact us, and we will work with you to get it running.