The data can be cut by a plane as shown in the file Cut.py . In the above example vtkPlane also takes input from the data to find the center. By now you should be able to directly read some Python vtk-code. Please take a look at the file AtomGlyphs.py . It is also possible to directly render a volume by making it partly transparent.
Volume rendering is particularly simple in vtk if the basis vectors of the unit cell are orthogonal.
In that case it is possible to represent the data as vtkStructuredPoints which is faster and with some special methods provided for volume rendering. Zero opacity corresponds to complete transparency while an opacity of one gives an object which is opague. By putting some of the stuff above together we can now show the electron density on two planes together with some contours. Please take a look at the file AllTogether.py . 08 Aug 2001 .