... in this repository using cmb/plugins/opencascade-session> as a template. + [ ] Copy the `cmake` directory from the opencascade session, renaming `ocXXX.cmake` to `exodusXXX.cmake`. + Remove the OpenCascade dependency and require VTK. + [ ] Copy the files from `smtk/session/opencascade` into `smtk/session/exodus` with the following changes: + [ ] Adapt `Shape.{h,cxx}` to omit OCC headers and a protected `vtkSmartPointer<vtkDataObject>` ivar (so that the node itself owns the data). This node type will serve as a base class for `ElementBlock`, `SideSet`, and `NodeSet` classes. The Shape should also have a `Component* m_parent` ivar that stores a raw pointer to its parent group (see below) and an `int m_pedigreeId` ivar referencing the block/set ID from the file. + [ ] Create a `Group.{h,cxx}` class similar to Shape that holds raw pointers to children Shapes instead of VTK data. This node type will serve as a base class for grouping all `ElementBlock`s (and `SideSet`s and `NodeSet`s) togther. It will also be a base class for a `File` node type that represents an exodus file. An exodus resource may contain multiple `File`s, each of which will reference groups of blocks by type. + [ ] Copy the `arcs/{ParentsAs,ChildrenAs}.h` files (but not the `.txx` files). Adapt the `.txx` files to provide implementations that use ivars in the shape and group classes to find parents/children. + [ ] Copy the `smtk/session/opencascade/vtk/Geometry.{h,cxx}` into `smtk/session/exodus/Geometry.{h,cxx}`, moving it out of the vtk directory since the exodus session will rely on VTK directly. Add the Geometry registration to `smtk/session/exodus/Registrar`. + [ ] Create new `Import`, `Read`, and `Write` operations. + [ ] The Import operation should create a `File` node and arcs that connect it to groups (one for element blocks, one for side sets, one for node sets). The `File` should have a string property that lists the source Exodus file. The `Shape` subclasses should have their pedigreee ID set. + [ ] The Write operation should include a JSON object mapping pedigree IDs to UUIDs (as well as JSON for the components, especially the Files so their locations are serialized). + [ ] The Read operation should use the above to determine what `File`s to load with a vtkExodusIIReader and how to map blocks from its output to the components created by deserializing the JSON.