For ASE, the vtk interface consists of Python modules for automatic visualization of positions, bonds, forces and volume data (e.g. wave functions) from an Atoms object, provided such data is made available by the calculator.
Note
The Python modules in ASE are intended to wrap lower-level functionality of the VTK object models in small and easy-to-comprehend classes. To be able to distinguish between build-in VTK objects and their wrappers, and because VTK uses the CamelCase naming convention whereas ASE uses lower-case cf. our coding conventions, all variables referring to VTK built-in types are prefixed by vtk_. However, both VTK and wrapper classes are named according to the standard vtkFooBar.