include/G4OCCT/G4OCCTAssemblyVolume.hh
| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | // SPDX-License-Identifier: LGPL-2.1-or-later | ||
| 2 | // Copyright (C) 2026 G4OCCT Contributors | ||
| 3 | |||
| 4 | /// @file G4OCCTAssemblyVolume.hh | ||
| 5 | /// @brief Declaration of G4OCCTAssemblyVolume. | ||
| 6 | |||
| 7 | #ifndef G4OCCT_G4OCCTAssemblyVolume_hh | ||
| 8 | #define G4OCCT_G4OCCTAssemblyVolume_hh | ||
| 9 | |||
| 10 | #include "G4OCCT/G4OCCTLogicalVolume.hh" | ||
| 11 | #include "G4OCCT/G4OCCTMaterialMap.hh" | ||
| 12 | #include "G4OCCT/G4OCCTSensitiveDetectorMap.hh" | ||
| 13 | |||
| 14 | #include <G4AssemblyVolume.hh> | ||
| 15 | #include <G4String.hh> | ||
| 16 | |||
| 17 | // OCCT (forward-declared where possible; full includes in .cc) | ||
| 18 | #include <TDF_Label.hxx> | ||
| 19 | #include <gp_Trsf.hxx> | ||
| 20 | |||
| 21 | #include <map> | ||
| 22 | #include <string> | ||
| 23 | |||
| 24 | /** | ||
| 25 | * @brief Extends Geant4's G4AssemblyVolume with an OCCT XDE label reference. | ||
| 26 | * | ||
| 27 | * Imports a STEP assembly file using the OCCT Extended Data Exchange (XDE) | ||
| 28 | * layer and constructs the corresponding Geant4 volume hierarchy. | ||
| 29 | * | ||
| 30 | * ## OCCT XDE to Geant4 mapping | ||
| 31 | * | ||
| 32 | * | XDE entity | Geant4 result | | ||
| 33 | * |-------------------------------------|-------------------------------------| | ||
| 34 | * | Top-level assembly label | `G4OCCTAssemblyVolume` (this class) | | ||
| 35 | * | Simple-shape label (first use) | `G4OCCTSolid` + `G4OCCTLogicalVolume` | | ||
| 36 | * | Simple-shape label (repeated use) | Shared `G4OCCTLogicalVolume` | | ||
| 37 | * | Reference label + TopLoc_Location | `AddPlacedVolume()` on parent assembly | | ||
| 38 | * | XDE name attribute | Volume name string | | ||
| 39 | * | XDE material attribute (if present) | `G4Material*` via `G4OCCTMaterialMap` | | ||
| 40 | * | Part name (fallback when no mat attr) | `G4Material*` via `G4OCCTMaterialMap` | | ||
| 41 | * | ||
| 42 | * ## Instance sharing | ||
| 43 | * | ||
| 44 | * When the same XDE shape label is referenced from multiple locations the | ||
| 45 | * corresponding `G4OCCTLogicalVolume` is created only once and reused for | ||
| 46 | * each placement (incrementing the copy number each time). This mirrors | ||
| 47 | * Geant4's own convention. | ||
| 48 | * | ||
| 49 | * ## Thread safety | ||
| 50 | * | ||
| 51 | * This class constructs the Geant4 geometry during `FromSTEP()` and is | ||
| 52 | * subsequently read-only. It inherits `G4AssemblyVolume`'s thread-safety | ||
| 53 | * guarantees after construction. | ||
| 54 | * | ||
| 55 | * ## Usage | ||
| 56 | * ```cpp | ||
| 57 | * G4OCCTMaterialMap matMap; | ||
| 58 | * matMap.Add("Al 6061-T6", G4NistManager::Instance()->FindOrBuildMaterial("G4_Al")); | ||
| 59 | * | ||
| 60 | * auto* assembly = G4OCCTAssemblyVolume::FromSTEP("detector.step", matMap); | ||
| 61 | * | ||
| 62 | * // In ConstructSDandField(): | ||
| 63 | * G4OCCTSensitiveDetectorMap sdMap; | ||
| 64 | * sdMap.Add("Absorber", myAbsoSD); | ||
| 65 | * assembly->ApplySDMap(sdMap); | ||
| 66 | * | ||
| 67 | * // Imprint into the world logical volume | ||
| 68 | * G4ThreeVector pos; | ||
| 69 | * G4RotationMatrix rot; | ||
| 70 | * assembly->MakeImprint(worldLV, pos, &rot); | ||
| 71 | * ``` | ||
| 72 | * | ||
| 73 | * See docs/step_assembly_import.md for the full design and background. | ||
| 74 | */ | ||
| 75 | class G4OCCTAssemblyVolume : public G4AssemblyVolume { | ||
| 76 | public: | ||
| 77 | 19 | G4OCCTAssemblyVolume() = default; | |
| 78 | 19 | ~G4OCCTAssemblyVolume() = default; | |
| 79 | |||
| 80 | /** | ||
| 81 | * Import a STEP assembly file and construct the Geant4 volume hierarchy. | ||
| 82 | * | ||
| 83 | * Reads the STEP file at @p path using `STEPCAFControl_Reader` (the OCCT | ||
| 84 | * XDE reader that preserves assembly structure, names, and material | ||
| 85 | * attributes). The label tree is traversed depth-first; each simple-shape | ||
| 86 | * leaf creates a `G4OCCTSolid` + `G4OCCTLogicalVolume`, and each placement | ||
| 87 | * is recorded via `AddPlacedVolume()` on the top-level assembly. | ||
| 88 | * | ||
| 89 | * Every material name encountered in the STEP file must be present in | ||
| 90 | * @p materialMap; an unresolved name triggers a fatal `G4Exception`. | ||
| 91 | * When a shape carries no XDE material attribute, its part (label) name | ||
| 92 | * is used as the lookup key instead, accommodating STEP writers that do | ||
| 93 | * not write material attributes. | ||
| 94 | * | ||
| 95 | * The leaf shapes are recentered (bounding-box centroid moved to the OCCT | ||
| 96 | * origin) before being wrapped in `G4OCCTSolid`; the recentering offset is | ||
| 97 | * absorbed into the placement transformation so that parts appear at their | ||
| 98 | * correct world positions. | ||
| 99 | * | ||
| 100 | * @param path Filesystem path to the STEP file. | ||
| 101 | * @param materialMap Map from STEP material name or part name to `G4Material*`. | ||
| 102 | * @return Pointer to a newly heap-allocated `G4OCCTAssemblyVolume` owned by | ||
| 103 | * the caller. The returned object already contains all child | ||
| 104 | * volumes; call `MakeImprint()` to place it in the world. | ||
| 105 | * @throws std::runtime_error if the file cannot be read or yields no shapes. | ||
| 106 | */ | ||
| 107 | static G4OCCTAssemblyVolume* FromSTEP(const std::string& path, | ||
| 108 | const G4OCCTMaterialMap& materialMap); | ||
| 109 | |||
| 110 | /** | ||
| 111 | * Return all logical volumes created during import, keyed by part name. | ||
| 112 | * | ||
| 113 | * The map is populated during `FromSTEP()`. When two STEP parts share | ||
| 114 | * the same name the later name is suffixed with `_<n>` so that every entry | ||
| 115 | * is unique. | ||
| 116 | */ | ||
| 117 | 17 | const std::map<G4String, G4OCCTLogicalVolume*>& GetLogicalVolumes() const { | |
| 118 | 17 | return fLogicalVolumes; | |
| 119 | } | ||
| 120 | |||
| 121 | /** | ||
| 122 | * Assign sensitive detectors to all logical volumes whose names match | ||
| 123 | * entries in @p sdMap. | ||
| 124 | * | ||
| 125 | * Iterates all logical volumes created during `FromSTEP()` and calls | ||
| 126 | * `sdMap.Resolve(name)` for each. When a non-null sensitive detector is | ||
| 127 | * returned, `G4LogicalVolume::SetSensitiveDetector()` is called on the | ||
| 128 | * corresponding logical volume. | ||
| 129 | * | ||
| 130 | * @param sdMap Map from volume-name patterns to sensitive detector pointers. | ||
| 131 | * @return Number of logical volumes for which a sensitive detector was assigned. | ||
| 132 | * | ||
| 133 | * @note Call this from `G4VUserDetectorConstruction::ConstructSDandField()` | ||
| 134 | * **after** both `FromSTEP()` and the SD objects have been created and | ||
| 135 | * registered with `G4SDManager`. | ||
| 136 | */ | ||
| 137 | std::size_t ApplySDMap(const G4OCCTSensitiveDetectorMap& sdMap); | ||
| 138 | |||
| 139 | private: | ||
| 140 | /// All G4OCCTLogicalVolume objects created during import, keyed by unique name. | ||
| 141 | std::map<G4String, G4OCCTLogicalVolume*> fLogicalVolumes; | ||
| 142 | |||
| 143 | /// Build context passed through the recursive traversal. | ||
| 144 | struct BuildContext; | ||
| 145 | |||
| 146 | /** | ||
| 147 | * Recursively import an XDE label into the Geant4 hierarchy. | ||
| 148 | * | ||
| 149 | * @param label XDE label to import (assembly, simple shape, or reference). | ||
| 150 | * @param parentAssembly Non-null assembly to add child volumes to; may be | ||
| 151 | * @c this (the top-level) or an intermediate | ||
| 152 | * `G4AssemblyVolume`. | ||
| 153 | * @param composedTrsf Accumulated rigid-body transformation from the root | ||
| 154 | * to this label's coordinate frame. | ||
| 155 | * @param ctx Mutable build context (prototype map, copy counter, …). | ||
| 156 | */ | ||
| 157 | static void ImportLabel(const TDF_Label& label, G4AssemblyVolume* parentAssembly, | ||
| 158 | const gp_Trsf& composedTrsf, BuildContext& ctx); | ||
| 159 | }; | ||
| 160 | |||
| 161 | #endif // G4OCCT_G4OCCTAssemblyVolume_hh | ||
| 162 |