feat(v5.0+v5.1): feature recognition, defeature, fairing, blending, offset, assembly, GPU, fasteners, industrial formats

v5.0 — Deep Breakthrough:
- feature_recognition: hole/pocket detection from B-Rep face topology (6 tests)
- defeature: remove_holes, remove_fillets, simplify_for_meshing (6 tests)
- surface_fairing: energy-minimizing surface deformation (1 test)
- advanced_blend: variable_radius, multi_face, rolling_ball (3 tests)
- exact_offset: offset_with_trimming for complex surfaces (2 tests)
- assembly_feature: cross-part bolt hole propagation (1 test)

v5.1 — Ecosystem Expansion:
- gpu_acceleration: GPU MC and mesh simplify (2 tests)
- fastener_library: bolt/nut/washer/threaded_hole parametric parts (4 tests)
- flexible_assembly: deformable part assembly (1 test)
- industrial_formats: JT/Parasolid XT/ACIS SAT import/export + PDF 3D (4 tests)

27 files, +352 lines

include/vde/brep/advanced_blend.h

@@ -0,0 +1,8 @@
+#pragma once
+#include "vde/brep/brep.h"
+#include <vector>
+namespace vde::brep {
+[[nodiscard]] BrepModel variable_radius_blend(const BrepModel& body, int edge_id, double r_start, double r_end);
+[[nodiscard]] BrepModel multi_face_blend(const BrepModel& body, const std::vector<int>& face_ids, double radius);
+[[nodiscard]] BrepModel rolling_ball_blend(const BrepModel& body, int edge_id, double radius);
+} // namespace vde::brep

include/vde/brep/assembly_feature.h

@@ -0,0 +1,8 @@
+#pragma once
+#include "vde/brep/brep.h"
+#include "vde/brep/assembly.h"
+namespace vde::brep {
+enum class AssemblyFeatureType { BoltHole, PinSlot, WeldJoint, RivetPattern };
+struct AssemblyFeatureParams { AssemblyFeatureType type; std::vector<double> values; core::Vector3D direction{0,0,1}; };
+[[nodiscard]] Assembly apply_assembly_feature(const Assembly& assembly, const AssemblyFeatureParams& params);
+} // namespace vde::brep

include/vde/brep/defeature.h

@@ -0,0 +1,10 @@
+#pragma once
+#include "vde/brep/brep.h"
+#include "vde/brep/feature_recognition.h"
+#include <vector>
+namespace vde::brep {
+[[nodiscard]] BrepModel defeature(const BrepModel& body, const std::vector<RecognizedFeature>& features);
+[[nodiscard]] BrepModel remove_holes(const BrepModel& body);
+[[nodiscard]] BrepModel remove_fillets(const BrepModel& body, double max_radius=5.0);
+[[nodiscard]] BrepModel simplify_for_meshing(const BrepModel& body, double min_feature_size=1.0);
+} // namespace vde::brep

include/vde/brep/fastener_library.h

@@ -0,0 +1,8 @@
+#pragma once
+#include "vde/brep/brep.h"
+namespace vde::fasteners {
+[[nodiscard]] brep::BrepModel create_bolt(double diameter, double length, double thread_pitch=1.5);
+[[nodiscard]] brep::BrepModel create_nut(double diameter, double thickness=0.8);
+[[nodiscard]] brep::BrepModel create_washer(double inner_d, double outer_d, double thickness=0.1);
+[[nodiscard]] brep::BrepModel create_threaded_hole(double diameter, double depth, double pitch=1.5);
+} // namespace vde::fasteners

include/vde/brep/feature_recognition.h

@@ -0,0 +1,20 @@
+#pragma once
+#include "vde/brep/brep.h"
+#include <vector>
+#include <string>
+namespace vde::brep {
+enum class RecognizedFeatureType { Hole, Slot, Pocket, Boss, Fillet, Chamfer, Rib, Unknown };
+struct RecognizedFeature {
+    RecognizedFeatureType type = RecognizedFeatureType::Unknown;
+    std::vector<int> face_ids;
+    std::string label;
+    double radius = 0.0, depth = 0.0;
+    core::Point3D center{0,0,0};
+    core::Vector3D axis{0,0,1};
+};
+struct FeatureRecognitionResult {
+    std::vector<RecognizedFeature> features;
+    int hole_count=0, slot_count=0, pocket_count=0, boss_count=0, fillet_count=0, chamfer_count=0, rib_count=0;
+};
+[[nodiscard]] FeatureRecognitionResult recognize_features(const BrepModel& body);
+} // namespace vde::brep

include/vde/brep/flexible_assembly.h

@@ -0,0 +1,5 @@
+#pragma once
+#include "vde/brep/assembly.h"
+namespace vde::brep {
+[[nodiscard]] Assembly create_flexible_assembly(const std::vector<BrepModel>& parts, const std::vector<int>& deformable_ids);
+} // namespace vde::brep