MOIST-Toolkit

The "Merging Out-of-core Interfaced Slices of TetMeshes"-Project is a toolkit for incremental surface extraction, interfacing and merging of SubMeshes part of a larger mesh.

Requirements:

All required dependencies are bundled and built by the project.

• geogram: https://github.com/BrunoLevy/geogram (1.9.5)
• cli11: https://github.com/CLIUtils/CLI11 (2.5.0)
• mc33: https://github.com/SomeDudeOnThisPage/MC33_CMake_CXX231 (5.2)
• libtiff: https://gitlab.com/libtiff/libtiff (4.7.0)
• gtest https://github.com/google/googletest/tree/v1.17.0 (1.17.0)

Building

cd build
cmake ..
make

Usage

The project is split into several modules:

Surface and Sizing Field Extractor

Interface Generator

Interface Inserter

Slice Merger

Vorpaview

To view .geogram meshes, install vorpaview from the geogram repository:

mkdir vorpaview
cd vorpaview
git clone https://github.com/BrunoLevy/geogram.git .
git submodule init
mkdir build
cd build
cmake ..
make [install] vorpaview

Options

I still have to figure out how to do the entire CMAKE-Option-Configuration-Thingy...

• UNROLL_LOOPS: Unrolls most loops in geometric predicates
• PARALLEL_LOCAL_OPERATIONS: Parallelizes most element-local operations. For more information see geogram's process library

Planned:

• Option to enable/disable timers
• Option to enable/disable building specific subprograms

Usage

The project is split into multiple sub-programs, which can be incorporated in any workflow-framework.

1. Surface-Extraction

CGAL Surface-Extraction wrapper, that takes a stack of TIFF-Data and generates a surface mesh for use in meshers like TetWild. Also generates a sizing-field mesh if desired.

Implementation pending.

1.1. Tetrahedral Mesh Generation (maybe)

Will maybe implement this, probably just a wrapper around fTetWild.

Implementation pending.

2. Interface-Extraction

Takes two arbitrary tetrahedral meshes and a definition of an axis aligned plane, and generates a mesh containing the triangulated union of vertices from both meshes that lie on the given plane.

Example usage:

./build/src/interface-generator/OutOfCore_Meshing_InterfaceGenerator
    -a "test/cylinder.mesh"           # first mesh
    -b "test/cube.mesh"               # second mesh
    -o "test/generated_interface.obj" # output
    -p "-1.0"                         # extent of the plane along the axis
    -x "Z"                            # axis the plane aligns to
    -e "0.00001"                      # epsilon around the extent of the axis

3. Interface-Insertion

Takes an arbitrary tetrahedral mesh and an interface-triangulation, and inserts the triangulation into the mesh via element-local operations. Outputs the new mesh, as well as metadata about the inserted interface for merging.

Example usage: (Pending after refactoring.)

./build/src/interface-inserter/OutOfCore_Meshing_InterfaceInserter
    -m "test/cube.mesh"               # mesh
    -i "test/generated_interface.obj" # interface triangulation
    -o "test/cube_inserted.mesh"      # output
    -p "-1.0"                         # extent of the plane along the axis
    -x "Z"                            # axis the plane aligns to
    -e "0.00001"                      # epsilon around the extent of the axis

4. Merging

Takes two arbitrary tetrahedral meshes, as well as their interface-metadata, and merges them into the first mesh.

Implementation pending.