Tarik Moussa
194effba97
feat(phase3f+3g): analytical Hessians + PI consolidation
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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
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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
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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
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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
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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
