Unresolved Issues While Exporting DAMASK Multi-Phase Simulation Results to VTK

[Anmol-Bakshi]

I’m performing a 2-phase DAMASK simulation (Iron and Ti) on a 3D-RVE using DAMASK_grid v3.0.1 and encountered multiple export-related issues during post-processing with the python-damask API.
Outputs like sigma, F, P, epsilon_U^0.0(F), epsilon_V^0.0(F) were correctly computed using:
r.add_strain(F='F', t='U', m=0.0)
r.add_strain(F='F', t='V', m=0.0)
r.add_stress_Cauchy()

r.export_VTK(output='*', mode='cell', target_dir='output_vtk')
ERROR: ValueError: shape mismatch: value array of shape (202612,3) could not be broadcast to indexing result of shape (202612,1)

Difficulty in Adding Phase-Specific Fields Manually
Attempted to export custom fields like:

• Orientation component: Iron/O_q0
• Slip system resistance: Ti/xi_sl_0
• Slip shear: Iron/gamma_sl_0
  But: r.phase['Iron']['mechanical']['O_q0'] = r.phase['Iron']['mechanical']['O'][:, 0].reshape(-1, 1) and other variants (r.result[...], r.data[...], r['...']), all resulted in:
• AttributeError: 'Result' object has no attribute 'result'
• TypeError: 'Result' object is not subscriptable
• IndexError: only integers, slices (...) are valid indices

Even dir(r) doesn’t show any direct method to assign new fields into the internal structure in a safe/documented way.

How to add orientations, gamma_sl, xi_sl correctly to export_VTK(...)?