Mesh & Scene IO

## Mesh IO

Mesh and Scene IO are backed by VTK and assimp along with a couple custom readers. All geometry can read/write through MeshIO.

// Read ".vtk" file into tetMesh
auto tetMesh = MeshIO::read<TetrahedralMesh>("C:/ExampleLocation/exampleFile.vtk");
// Write out
MeshIO::write(tetMesh , "C:/MyLocationToWriteTo/exampleFileOut.vtk");

## SceneObject IO

The VisualObjectImporter is for importing more complex objects in the scene that cannot be described by a single geometry. This may involve multiple separable meshes, materials, textures, etc. Or even hierarchically defined meshes with multiple parts (it will flatten). It supports reading 3ds, obj, fbx, and dae. It can be used as follows:

std::shared_ptr<SceneObject> myObject = ObjectIO::importSceneObject("Object Name", "C:/ExamplePath/ExampleFile.dae", "C:/ExamplePath/");
// This can then be added to the scene
scene->addSceneObject(myObject);

## Supported Geometry Types

File Format	Extension	IO	Backend	Geometry
VTK	.vtk	read/write	VTK	PointSet, LineMesh, SurfaceMesh, TetrahedralMesh, HexahedralMesh
VTU	.vtu	read/write	VTK	TetrahedralMesh , HexahedralMesh
VTP	.vtp	read/write	VTK	SurfaceMesh
Stereolithic	.stl	read/write	VTK	SurfaceMesh
Polygon	.ply	read/write	VTK	SurfaceMesh
Nearly Raw Raster Data	.nrrd	read/write	VTK	ImageData
NIFTI	.nii	read/write	VTK	ImageData
Meta Image	.mhd + .raw	read/write	VTK	ImageData
Joint Photo Experts Group	.jpg or jpeg	read/write	VTK	ImageData
Portable Network Graphics	.png	read/write	VTK	ImageData
Bitmap	.bmp	read/write	VTK	ImageData
Wavefront	.obj	read	Assimp	LineMesh, SurfaceMesh
Collada	.dae	read	Assimp	LineMesh, SurfaceMesh
Filmbox	.fbx	read	Assimp	LineMesh, SurfaceMesh
Autodesk 3ds	.3ds	read	Assimp	LineMesh, SurfaceMesh
Vega	.veg	read/write	VegaFEM	TetrahedralMesh, HexahedralMesh
GMSH	.msh	read/write	iMSTK	LineMesh, SurfaceMesh, TetrahedralMesh, HexahedralMesh

• Note .mhd is the only format that supports read/write of 3d images with linear offsets.
• No image format here supports orientations
• TetWild can generate TetrahedralMesh's from SurfaceMesh in the ".msh" format, directly read by iMSTK.
• iMSTK does not support any mixed cell geometries