upxo.pxtal.twinned_simple_3d.steps.steps_twin_generation module

Twin Generation – Part K of the Twinned FCC walkthrough.

Introduces primary + secondary twins into the oriented, host-allocated base structure, then cleans the result (removes spike voxels / splits non-convex lobes left behind by the voxel carving).

upxo.pxtal.twinned_simple_3d.steps.steps_twin_generation.generate_twins(base, rg, parent_info, assigner, twin_thickness, vf_targets=None, csl_label='S3  (twin)', n_lamellae_per_host=10, nucleation_site='gb_centroid', meshing_route='conformal', min_thick_conformal=2, min_thick_nonconformal=1, min_host_vox=8, tvf_tolerance=0.05, tvf_2d_to_3d_scale=1.15, thick_scale_factor=0.8, max_thick_um=None, max_vf_per_host=0.5, prob_separated=0.3, prob_contacting=0.7, prob_sec_outward=0.6, prob_sec_inward=0.4, schmid_dir=(0.0, 0.0, 1.0), host_schmid_weight=1.0, use_schmid=True, orient_scatter_deg=1.5, rng_seed=123)[source]

Introduces primary twins (at host grain-boundary centroids by default) then secondary twins (nucleating inward/outward from the primaries), targeting the EBSD twin-area-fraction (TVF) for csl_label.

twin_thickness: the dict from steps_ebsd_analysis_2.compute_twin_thickness – Twin Generation reuses that measurement rather than recomputing it (including whatever abrupt-boundary threshold it was computed with). assigner: the result of steps_orientation_assignment.assign_orientations. vf_targets: the dict from steps_ebsd_analysis_2.compute_vf_partition (‘tvf_stage1’/’tvf_secondary_2a’/’tvf_secondary_2b’). Passing this is what makes primary-twin introduction stop at its own Stage-1 share of the total EBSD twin fraction, instead of the combined overall fraction – without it, primary twins alone can reach the full target and secondary introduction never triggers (0 secondary twins). None (default) falls back to that combined-fraction behaviour. max_thick_um: None (default) means no cap; pass a number to enable one.

Returns:

  • TwinGenerator3D (tg – tg.lgi_twinned/tg.all_quats/tg.twin_role/)

  • tg.twin_parent_of feed steps_twin_generation.clean_structure();

  • tg.summary()/tg.diagnose(tvf) give the achieved-vs-target report.

upxo.pxtal.twinned_simple_3d.steps.steps_twin_generation.clean_structure(tg, min_voxels=0, n_passes=5, upscale_fallback=False, split_jitter_deg=0.0, rng_seed=7, do_spike_removal=True, do_lobe_split=True, verbose=True)[source]

Topology Cleaning – removes spike voxels and splits non-convex (“lobed”) grains the twin-carving step can leave behind, recursively up to n_passes (capped at 20 as a safety limit).

Returns:

  • (cleaner, n_passes_run) (cleaner (StructureCleaner3D) carries)

  • lgi_clean/all_quats_clean/twin_role_clean/twin_parent_of_clean –

  • pass it into steps_post_twin_validation’s functions.