From SOFAWiki

New architecture of MeshLoader/ImageLoader

These components can be used in SOFA since revision (r5359). File formats supported are:

- In SOFA trunk: .obj, .vtk, .gmsh, .trian, .xsp
- In SOFA at asclepios (still in project): .tr, .tr3D, .atr3D, .vol, .tet3D, .atet3D

There is still some issues. See ticket [1].

Volumetric msh files can be generated based on surface meshes, using an external tool (with some limitations, though): http://www.dennis2society.de/main/archives/285 Another tool is presented here: http://smart.seecs.nust.edu.pk/tutorial.html

New architecture

Comments:

- The branch of Image loader has not been implemented yet.
- The fonction canCreate will be used by the factory to create the appropriate loader when no specific loader is used (i.e "<MeshLoader filename="myfile.obj />" in this case the function will recognize the file extension) or if the file format is unknown.

How to use it

To use these specific loaders, you have to connect manually Data dependencies in the XML scene file. For example:

<MeshObjLoader name="ObjLoader" filename="mesh/my_mesh.obj" />
<MechanicalObject name="dofs" position="@ObjLoader.position" />
<Node>
 <TriangleSetTopologyContainer name="triangulation" triangles="@../ObjLoader.triangles" position="@../ObjLoader.position" />
</Node>

If you want to connect all the Data from the Loader to a component. You can use the attribute "src". A parser will automatically connect together Data named the same in the loader and in the component. Using the attribute "src", the previous example can be written this way:

<MeshObjLoader name="ObjLoader" filename="mesh/my_mesh.obj" />
<MechanicalObject name="dofs" src="@ObjLoader" />
<Node>
 <TriangleSetTopologyContainer name="triangulation" src="@../ObjLoader" />
</Node>

Notes that, when using this attribute, Data not empty will not be overwrite. For example:

<MeshObjLoader name="ObjLoader" filename="mesh/my_mesh.obj" />
<MechanicalObject name="dofs" src="@ObjLoader" position="0 0 0"/>

In this case, the Data position of the !MechanicalObject will not be field by the !MeshObjLoader. Thus, it is possible to combine Data dependencies.

Data standard names

It is important to have homogeneous Data names to be able to connect Data and to use the attribute "src". That is why this section propose standard names used Loaders:

Standard names for [doxygen:sofa::core::componentmodel::loader::MeshLoader MeshLoader]:

list of points coordinates:
  position     =>   type: Data < helper::vector <Vec3d> > positions;
 
For 2D elements:
  edges        =>  type: Data< helper::vector< helper::fixed_array <unsigned int,2> > > edges;
  triangles    =>  type: Data< helper::vector< helper::fixed_array <unsigned int,3> > > triangles;
  Quads        =>  type: Data< helper::vector< helper::fixed_array <unsigned int,4> > > quads;
  polygons     =>  type: Data< helper::vector<helper::vector <unsigned int> > > polygons;
 
For 3D elements:
  tetrahedra   =>  type: Data< helper::vector< helper::fixed_array <unsigned int,4> > > tetrahedra;
  hexahedra    =>  type: Data< helper::vector< helper::fixed_array <unsigned int,8> > > hexahedra;

Standard names for [doxygen:sofa::core::componentmodel::loader::ImageLoader ImageLoader]:

 Not yet implemented.

Generic mesh loaders

This is a list of the loaders available in SOFA, with their specific Data.

[doxygen:sofa::component::loader::MeshGmshLoader MeshGmshLoader]: (example in: trunk/Sofa/examples/Components/loader/MeshGmshLoader.scn)

  No other Data.

[doxygen:sofa::component::loader::MeshObjLoader MeshObjLoader]: (example in: trunk/Sofa/examples/Components/loader/MeshObjLoader.scn)

  texturesList =>  type: Data <helper::vector <helper::vector <int> > > texturesList;
  texcoords    =>  type: Data< helper::vector< sofa::defaulttype::Vector2> > texCoords;
  normalsList  =>  type: Data <helper::vector <helper::vector <int> > > normalsList;
  normals      =>  type: Data< helper::vector< sofa::defaulttype::Vector3> > normals;
 
  Data <helper::vector <Material> > materials;
    With Material, a inner class of MeshObjLoader

[doxygen:sofa::component::loader::MeshTrianLoader MeshTrianLoader]: (example in: trunk/Sofa/examples/Components/loader/MeshTrianLoader.scn)

  neighborTable          => type: Data <helper::vector < helper::fixed_array <int,3> > > neighborTable;
  edgesOnBorder          => type: Data <helper::vector < helper::vector <unsigned int> > > edgesOnBorder;
  trianglesOnBorderList  => type: Data < helper::vector <unsigned int> > trianglesOnBorderList;

[doxygen:sofa::component::loader::MeshVTKLoader MeshVTKLoader]: (example in: trunk/Sofa/examples/Components/loader/MeshVTKLoader.scn)

  No other Data. For the moment.

[doxygen:sofa::component::loader::MeshXspLoader MeshXspLoader]:

  gravity      =>  type: Data <helper::vector <defaulttype::Vector3> > gravity;
  viscosity    =>  type: Data <helper::vector <double> > viscosity;

Current architecture of MeshLoader/ImageLoader

TODO