GAMMA

GAMMA — Geometry-Aware Mesh Movement Analysis performs differentiable boundary-surface mesh motion. Given a CAD outer mould line and a surface mesh that must follow it, GAMMA moves every mesh node as the geometry deforms, carries analytic derivatives through the CSDL graph, and reports mesh-quality and inversion diagnostics so validity is checked rather than guaranteed.

Install the gamma-mdo distribution and import its public Python namespace as bsm3.

E175 mesh deformation

Animation of the E175 triangular surface mesh deforming with its geometry — Triangular surface mesh

Animation of the E175 quad-dominant surface mesh deforming with its geometry — Quad-dominant surface mesh

The animations are served from the v0.2.0a1 release, so they are not included in repository clones or package installations.

The pipeline is:

geometry parameterization
    -> deformed component coefficients
    -> intersection curves between components
    -> graph-Laplacian surface motion with regularization
    -> reprojection onto the deformed outer mould line
    -> quality and inversion diagnostics
    -> optional volume-mesh motion

bsm3.mesh_motion is the intended entry point and is deliberately small: input files, a GeometryModel describing what moves, a MeshMotion settings object describing how the mesh follows, and run to evaluate it.

import bsm3.mesh_motion as mm

result = mm.run(
    inputs=mm.InputFiles(
        geometry_file=step_path,
        surface_mesh_file=surface_path,
        cache_directory=cache_path,
    ),
    geometry=geometry,
    motion=mm.MeshMotion(quality=mm.QualityChecks(surface=True)),
    recorder=recorder,
)
result.print_summary()

Where to start

Installation — the validated Python 3.12 dependency stack and the install flags that protect an existing solver environment.
E175 example — the five-stage workflow, based on the tracked examples/e175_surface_deformation.py.
External parameterization — the generic contract: bring your own differentiable coefficients.
API reference — the public bsm3.mesh_motion surface.
Background — what each pipeline stage does and why.
Integrations and troubleshooting — honest status of DAFoam/OpenFOAM, MPI, VortexAD, mesh generation, and assets.