conformallab/ConformalLabpp
3
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 1 Wiki Activity
49 Commits 11 Branches 5 Tags
e70689d29f4701bb0a3f90f5ddf35bda7161f899
Commit Graph

6 Commits

Author SHA1 Message Date
Tarik Moussa
e70689d29f feat(phase4a+4b): Newton solver + CGAL mesh I/O 
Phase 4a — newton_solver.hpp:
  - newton_euclidean(): SimplicialLDLT on H (PSD); solves H·Δx = −G
  - newton_spherical(): SimplicialLDLT on −H (NSD→PSD); solves (−H)·Δx = G
  - Backtracking line search (halving α up to 20×) for global convergence
  - NewtonResult struct: x, iterations, grad_inf_norm, converged
  - 7 tests: 4 spherical (convergence, few iters, large perturbation,
    field consistency) + 3 Euclidean (triangle pinned, quad pinned,
    mixed pinned — all with natural-theta equilibrium at x=0)

Phase 4b — mesh_io.hpp:
  - read_mesh() / write_mesh(): CGAL::IO::read/write_polygon_mesh wrappers
  - load_mesh() / save_mesh(): throwing convenience versions
  - Supports OFF, OBJ, PLY (format detected by file extension)
  - 6 tests: OFF round-trip (tet + quad), OBJ round-trip, missing-file throw,
    vertex-position preservation, save/load convenience wrappers

All 75 cgal tests pass (3 skipped as before).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
 2026-05-12 17:35:00 +02:00
Tarik Moussa
194effba97 feat(phase3f+3g): analytical Hessians + PI consolidation 
Phase 3g — constants.hpp:
  - Introduce conformallab::PI and TWO_PI in a single constants.hpp
  - Remove scattered local PI/pi definitions from hyper_ideal_geometry.hpp,
    hyper_ideal_utility.hpp, euclidean_functional.hpp, mesh_builder.hpp,
    spherical_geometry.hpp (backward-compatible PI_SPHER alias kept)

Phase 3f — Euclidean Hessian (euclidean_hessian.hpp):
  - Cotangent-Laplace operator (Pinkall–Polthier 1993)
  - euclidean_cot_weights() helper + euclidean_hessian() + hessian_check_euclidean()
  - Correct Pinkall–Polthier 1/2 normalization factor
  - 8 tests: cot weights, symmetry, null-space (H·1=0), PSD, FD × 4 meshes

Phase 3f — Spherical Hessian (spherical_hessian.hpp):
  - Derives ∂α_i/∂u_j directly from the spherical law of cosines:
      ∂α1/∂l_opp  = sin(l_opp) / [sin(l_a)·sin(l_b)·sin(α1)]
      ∂α1/∂l_adj  = [cot(l_adj)·cos(α1) − cot(l_other)] / sin(α1)
    then chains with ∂l/∂λ = tan(l/2)
  - spherical_cot_weights() kept as a standalone helper (tested separately)
  - 8 tests: cot weights, symmetry, correct null-space & sign-convention
    (H·1 ≠ 0; H is NSD at equilibrium), FD × 3 meshes

All 62 cgal tests pass (3 skipped as before).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
 2026-05-12 17:22:28 +02:00
Tarik Moussa
8c353bb884 feat(phase3d+3e): port EuclideanCyclicFunctional + add SphericalFunctional gauge-fix 
Phase 3d — EuclideanCyclicFunctional:
  • euclidean_geometry.hpp: t-value / atan2 corner-angle formula with
    centering trick (μ = (Λ̃₁₂+Λ̃₂₃+Λ̃₃₁)/6) for numerical stability
  • euclidean_functional.hpp: EuclideanMaps bundle, gradient (G_v = Θ_v − Σα_v,
    G_e = α_opp⁺ + α_opp⁻ − φ_e), 10-point GL path-integral energy,
    gradient_check_euclidean — identical halfedge convention to SphericalFunctional
  • test_euclidean_functional.cpp: 11 tests (1 skip) covering angle formula,
    right-isosceles triangle, angle sum = π, degenerate detection, gradient
    checks on triangle/quad-strip/tetrahedron/fan-5/mixed-pinned, NaN check

Phase 3e — Spherical gauge-fix:
  • spherical_gauge_shift(): Newton + backtracking line search to find t*
    where ΣG_v(x + t·1) = 0 (maximises E along the global scale direction);
    bisection used when sign change is detectable, Newton+backtrack otherwise
  • apply_spherical_gauge(): in-place wrapper
  • 3 new tests: GaugeFix_SpherTetVertexZerosSumGv, GaugeFix_ApplyInPlace,
    GaugeFix_AlreadyAtGaugeReturnsTNearZero

Total: 45 cgal tests pass, 3 skipped (@Ignore Hessian stubs, one per functional)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
 2026-05-12 07:39:14 +02:00
Tarik Moussa
a4c2a89e7e feat(phase3c): port SphericalFunctional onto ConformalMesh; update README 
New headers:
- spherical_geometry.hpp: spherical arc length l(λ) and half-angle formula
  for interior angles of a spherical triangle (SphericalFaceAngles struct)
- spherical_functional.hpp: SphericalMaps bundle, setup/assign DOF helpers,
  compute_lambda0_from_mesh(), gradient (Θ_v − Σα_v; Schläfli edge formula),
  energy via 10-point Gauss-Legendre path integral, gradient_check_spherical()

Updated:
- mesh_builder.hpp: add make_spherical_tetrahedron() (vertices on unit sphere)
  and make_octahedron_face() (single right-angled spherical triangle)
- tests/cgal/CMakeLists.txt: enable test_spherical_functional.cpp
- README.md: rewrite for CGAL-package goal, two test targets, all headers,
  updated project tree, Phase progress table, key design decisions

Tests (cgal.SphericalFunctional.*): 8 active + 1 skip
- OctaFaceAnglesAreRightAngles, SpherTetAngleSumExceedsPi
- GradientCheck_{OctaFaceVertex, SpherTetVertex, SpherTetAllDofs,
  SpherFan4Vertex, MixedPinnedVertices}
- AnglesFiniteAtKnownPoint
All 30 cgal.* tests pass (2 @Ignore skips).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
 2026-05-12 00:01:24 +02:00
Tarik Moussa
516ac89bd8 feat(phase3b): port HyperIdealFunctional energy + gradient onto ConformalMesh 
Implements the hyper-ideal discrete conformal map functional on
CGAL::Surface_mesh. The energy and analytic gradient are ported directly
from HyperIdealFunctional.java; correctness is verified via a
finite-difference gradient check (same eps=1E-5 / tol=1E-4 as Java).

New files:
  include/hyper_ideal_geometry.hpp    — ζ, ζ₁₃, ζ₁₄, ζ₁₅, lij, αij, σi, σij
  include/hyper_ideal_functional.hpp  — HyperIdealMaps, evaluate_hyper_ideal,
                                        gradient_check
  tests/cgal/test_hyper_ideal_functional.cpp  — 6 tests (1 skipped @Ignore)

Test results (local, -DWITH_CGAL=ON):
  conformallab_cgal_tests: 21 registered | 20 passed | 1 skipped | 0 failed
    - GradientCheck_AllHyperIdealTriangle   ✓
    - GradientCheck_ExtendedDomain          ✓
    - GradientCheck_TetrahedronAllVariable  ✓
    - EnergyFiniteAtTestPoint               ✓
    - GradientCheck_MixedIdealHyperIdeal    ✓
    - GradientCheck_Fan6AllVariable         ✓

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
 2026-05-11 23:10:23 +02:00
Tarik Moussa
bf9c323d60 feat(phase3a): introduce CGAL Surface_mesh as ConformalMesh foundation 
Replaces the Java CoHDS with CGAL::Surface_mesh<Point3> (Simple_cartesian
kernel). Adds domain-specific property maps for lambda/theta/idx/alpha and
face geometry type — the direct C++ equivalent of CoVertex/CoEdge adapters.

New files:
  include/conformal_mesh.hpp   — ConformalMesh type + property-map helpers
  include/mesh_builder.hpp     — mesh factories (triangle, tetrahedron,
                                 quad-strip, fan) for tests and examples
  tests/cgal/                  — second test executable (conformallab_cgal_tests)
                                 built only with -DWITH_CGAL=ON

Test results (local, -DWITH_CGAL=ON):
  conformallab_tests:      36 registered | 23 passed | 13 skipped | 0 failed
  conformallab_cgal_tests: 14 registered | 14 passed |  0 skipped | 0 failed

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
 2026-05-11 18:36:21 +02:00