bulldozer.py and bulldozerVTK.py show how simple it is possible to simulate relatively difficult things.

bulldozer.py is using Law2_ScGeom_FrictPhys_CundallStrack constitutive law for interaction between elements.
It stores screenshots from simulation in /tmp/bulldozer-????.png files and creates video then.

bulldozerVTK.py is using Law2_ScGeom_ViscElPhys_Basic - visco-elastic model for interaction between elements.
Also it saves snapshots in VTK-format in /tmp/bulldozer-*.vtu files. If you open those with paraview
(or other VTK-based) program, you can create video from them, make screenshots etc.

