[IgaApplication]:: [IgaModelerSbm] Analytical projection feature added if importing NURBS curves

[ThomasLillieskold]

📝 Description

Add analytical projection onto 2D NURBS skins for the Shifted Boundary Method (SBM) in IgaApplication. SBM settings now select "analytical" or "linealized" through sbm_parameters.projection_type.

Key changes

• Project SBM quadrature points onto NURBS curves and create projection nodes with oriented normals.
• Allow SBM conditions to use those nodes while retaining support for discretized skin projections.
• Validate projection settings and NURBS layer to condition mappings.
• Add tests for curved and rational NURBS skins, both projection modes, and invalid settings.

Validation

• Focused Python tests passed: test_modelers_sbm.py (21 tests) and test_import_nurbs_modeler.py (6 tests).
• C++ tests passed: KratosIgaCoreTest (25 passed, 8 skipped), KratosCoreTest (1612 passed, 4 skipped), and KratosStructuralMechanicsCoreTest (116 passed).

🆕 Changelog

• Added analytical projection onto 2D NURBS skins for SBM in IgaApplication.
• Added explicit selection between analytical and linealized SBM projection.
• Added projection node support and validation for NURBS condition mappings.

[Copilot]

Copilot review overview

🟡 Changes recommended

Analytical quadrature reads the wrong setting key, and importer validation tests are omitted from standard suites.

Review effort: Balanced
Findings: 1 · 1 · 1

Open (3)

• Use quadrature_method for analytical projection · New
• Register importer validation tests in standard test suites · New
• Fix typo in user-facing search error message · New

What changed in this PR

Adds analytical 2D NURBS projection support to IgaApplication’s Shifted Boundary Method.

Changes:

• Introduces selectable analytical and linealized projection modes.
• Creates projection nodes with oriented normals for SBM conditions.
• Adds projection validation and curved/rational NURBS tests.

File	Description
test_stokes_sbm_conditions.py	Selects linealized projection.
test_stokes_sbm_conditions_3d.py	Selects linealized 3D projection.
test_stokes_elements_and_conditions.py	Updates support-condition settings.
test_sbm_laplacian_3d.py	Selects linealized projection.
test_modelers_sbm.py	Tests analytical projections and validation.
test_import_nurbs_modeler.py	Tests NURBS mapping validation.
sbm_solid_tests.py	Updates solid SBM settings.
complex_2d_nurbs.json	Reorients a NURBS curve.
test_sbm_3d_workflow.cpp	Updates 3D workflow settings.
snake_sbm_process.cpp	Retains original NURBS geometries.
import_nurbs_sbm_modeler.cpp	Validates condition mappings.
iga_modeler_sbm.h	Declares projection-specific creation methods.
iga_modeler_sbm.cpp	Implements analytical and linealized projections.
sbm_solid_condition.cpp	Supports explicit projection nodes.
sbm_load_solid_condition.cpp	Uses projected nodes and normals.
sbm_laplacian_condition_neumann.cpp	Uses analytical projection data.
sbm_laplacian_condition_dirichlet.cpp	Supports explicit projection nodes.
sbm_fluid_condition_dirichlet.cpp	Supports explicit projection nodes.

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