概述

本教程基于直升机模型存在的诸多问题提供了一系列修复方法。通过调用 GeomE 的 API 对模型进行几何编辑操作以实现对模型的修复。

命名空间

为了示例代码清晰，使用命名空间。

using namespace std;
using namespace AMCAX;
using namespace GeomE;

直升机模型中存在的问题

当前直升机模型存在碎面、缝隙孔洞等问题。如下图所示：

碎面

在机翼下方存在两个碎面（高亮位置）。

缝隙孔洞

在机头和机尾存在一些缝隙孔洞（红色位置）。

修复方法

辅助函数

为使示例代码结构更清晰、逻辑更聚焦，我们对以下辅助功能进行了封装。

// Read
bool readtopo(TopoShape& s, const string& mfile)
{
    if (!std::filesystem::exists(mfile)) {
        cout << "File not found!" << endl;
        return false;
    }
    string suffix = mfile.substr(mfile.find_last_of('.') + 1);
    std::transform(suffix.begin(), suffix.end(), suffix.begin(), [](unsigned char c) {
        return std::tolower(c);
        });
    // Check the file extension. If it's .stp or .step, call StepDataTool; if it's .brep, call OCCTTool
    if (suffix == "stp" || suffix == "step") {
        return STEP::StepDataTool::Read(s, mfile);
    }
    else if (suffix == "brep") {
        return OCCTIO::OCCTTool::Read(s, mfile);
    }
    else {
        std::cout << "Unsupported file format!" << endl;
        return false;
    }
}
 
 // Write
 bool writetopo(const TopoShape& s, const string& outfile)
 {
     string suffix = outfile.substr(outfile.find_last_of('.') + 1);
     transform(suffix.begin(), suffix.end(), suffix.begin(), [](unsigned char c) {
         return tolower(c);
         });
     // Check the file extension. If it's .stp or .step, call StepDataTool; if it's .brep, call OCCTTool
     if (suffix == "stp" || suffix == "step")
         return STEP::StepDataTool::Write(s, outfile);
     else if (suffix == "brep")
         return OCCTIO::OCCTTool::Write(s, outfile);
     else {
         cout << "Unsupported output file format: " << suffix << endl;
         return false;
     }
 }

碎面融合

在机身的左侧和右侧均存在碎面，将通过以下代码将碎面进行融合。

TopoShape combineFaces(TopoShape& shape)
{
    IndexSet<TopoShape> edges, faces;
    TopoExplorerTool::MapShapes(shape, ShapeType::Face, faces);
    TopoExplorerTool::MapShapes(shape, ShapeType::Edge, edges);
    FaceEditor faceEditor;
    // Right side of the fuselage
    {
        // Delete two faces
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[17 - 1]));
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[19 - 1]));
        // Construct a new face based on the given set of edges and an existing face
        // Top
        IndexSet<TopoShape> set;// All edges to be fused
        set.insert(edges[110 - 1]);
        set.insert(edges[111 - 1]);
        set.insert(edges[109 - 1]);
        set.insert(edges[28 - 1]);
        set.insert(edges[27 - 1]);
        faceEditor.BuildFaceFromSurface(shape, set, TopoCast::Face(faces[18 - 1]));
        // Bottom
        IndexSet<TopoShape> setdown;// All edges to be fused
        setdown.insert(edges[114 - 1]);
        setdown.insert(edges[115 - 1]);
        setdown.insert(edges[116 - 1]);
        setdown.insert(edges[35 - 1]);
        faceEditor.BuildFaceFromSurface(shape, setdown, TopoCast::Face(faces[18 - 1]));
    }
    // Left side of the fuselage
    {
        // Delete three faces
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[52 - 1]));
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[26 - 1]));
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[24 - 1]));
        // Construct a new face based on the given set of edges and an existing face
        // Top
        IndexSet<TopoShape> set;// All edges to be fused
        set.insert(edges[233 - 1]);
        set.insert(edges[138 - 1]);
        set.insert(edges[61 - 1]);
        set.insert(edges[60 - 1]);
        set.insert(edges[135 - 1]);
        set.insert(edges[190 - 1]);
        set.insert(edges[137 - 1]);
        faceEditor.BuildFaceFromSurface(shape, set, TopoCast::Face(faces[25 - 1]));
        // Bottom
        IndexSet<TopoShape> setdown;// All edges to be fused
        setdown.insert(edges[130 - 1]);
        setdown.insert(edges[131 - 1]);
        setdown.insert(edges[132 - 1]);
        setdown.insert(edges[53 - 1]);
        faceEditor.BuildFaceFromSurface(shape, setdown, TopoCast::Face(faces[25 - 1]));
    }
    // Unify faces and edges of the shape
    auto result = ShapeFixTool::UpgradeUnifySameDomain(shape);
    writetopo(result, "combineFaces.brep");
    return result;
}

结果如下图所示，碎面已融合。

在上述代码中，出现的 faces[17 - 1] 等索引信息是通过 FreeCAD 软件查看到的，它是拓扑对象的索引序号。查看方法如下：

安装 FreeCAD 软件
导入模型文件
点击拓扑对象
查看软件左侧便能看到序号，如下图所示

注意：模型修改后，原有对象索引会发生变化。如需再次获取目标对象索引，应基于最新修改后的模型重新查询，不可沿用初始模型的索引值。

缝隙缝合

在融合碎面后，继续对融合后的模型进行缝隙缝合。

void sewEdges(TopoShape& shape, const string& filePath, int e1, int e2, double tolerance)
{
    cout << "Applying auto fix (tolerance = " << tolerance << ") to file: " << filePath << endl;
    try {
        // Find all free edges
        IndexSet<TopoShape> edges;
        TopoExplorerTool::MapShapes(shape, ShapeType::Edge, edges);
        IndexSet<TopoShape> list = GeomE::DetectTool::DetectFreeEdges(shape);
        // Sew two edges
        TopoEdge edge1 = TopoCast::Edge(edges[e1]);
        TopoEdge edge2 = TopoCast::Edge(edges[e2]);
        EdgeEditor editor;
        editor.SewEdges(shape, edge1, edge2, tolerance);
    }
    catch (const exception& e) {
        cout << "Auto fix failed for file " << filePath << ". Exception: " << e.what() << endl;
        return;
    }
 
    // Construct the output filename by appending "_autosew" suffix to the original filename
    filesystem::path p(filePath);
    string stem = p.stem().string(); 
    string extension = p.extension().string();
    extension = ".step";
    string outFile = (p.parent_path() / (stem + "_autosew" + extension)).string();
    // Write
    if (writetopo(shape, outFile))
        cout << "Auto fix succeeded, output saved to: " << outFile << endl;
    else
        cout << "Failed to write output file: " << outFile << endl;
    cout << "success auto fix" << endl;
}
 
sewEdges(shape, "./combineFaces.step", 187 - 1, 247 - 1, 0.007);

结果如下图所示，由两条边形成的缝隙已被修复。

填补孔洞

通过构造新的延长面以填补机头窗户处细长三角形空洞。

TopoShape fillhole_with_newface(TopoShape& shape)
{
    IndexSet<TopoShape> edges, faces;
    TopoExplorerTool::MapShapes(shape, ShapeType::Edge, edges);
    TopoExplorerTool::MapShapes(shape, ShapeType::Face, faces);
    IndexSet<TopoShape> set;
    set.insert(edges[14 - 1]);
    set.insert(edges[16 - 1]);
    set.insert(edges[88 - 1]);
 
    FaceEditor faceEditor;
    // Construct a new face extending from Face 2, using specified edge set. The new face shares the same surface geometry as Face 2.
    faceEditor.BuildFaceFromSurface(shape, set, TopoCast::Face(faces[3 - 1]));
    // Unify faces and edges of the shape
    auto result = ShapeFixTool::UpgradeUnifySameDomain(shape);
    // Write
    writetopo(result, "fillhole_with_newface.step");
    return result;
}

结果如下图所示，细长三角形空洞已消除。

点击这里example04可获得直升机模型修复与完善示例的完整源码，大家根据学习需要自行下载。

附录

#include <iostream>
#include <vector>
#include <string>
#include <filesystem> 
#include <modeling/MakeShapeTool.hpp>
#include <modeling/MakeSolid.hpp>
#include <topology/TopoCast.hpp>
#include <topology/TopoSolid.hpp>
#include <topology/TopoShell.hpp>
#include <topology/TopoExplorerTool.hpp>
#include <topology/TopoTool.hpp>
#include <shapeEdit/EdgeEditor.hpp>
#include <shapeEdit/EdgeEditor.hpp>
#include <shapeEdit/FaceEditor.hpp>
#include <shapeEdit/DetectTool.hpp>
#include <occtio/OCCTTool.hpp>
#include <step/StepDataTool.hpp>
#include <fillet/MakeFillet.hpp>
#include <healing/ShapeFixTool.hpp>
#include <boolean/BoolBRepDefeaturing.hpp>
 
 
using namespace std;
using namespace AMCAX;
using namespace GeomE;
 
// Read
bool readtopo(TopoShape& s, const string& mfile)
{
    if (!std::filesystem::exists(mfile)) {
        cout << "File not found!" << endl;
        return false;
    }
    string suffix = mfile.substr(mfile.find_last_of('.') + 1);
    std::transform(suffix.begin(), suffix.end(), suffix.begin(), [](unsigned char c) {
        return std::tolower(c);
        });
    // Check the file extension. If it's .stp or .step, call StepDataTool; if it's .brep, call OCCTTool
    if (suffix == "stp" || suffix == "step") {
        return STEP::StepDataTool::Read(s, mfile);
    }
    else if (suffix == "brep") {
        return OCCTIO::OCCTTool::Read(s, mfile);
    }
    else {
        std::cout << "Unsupported file format!" << endl;
        return false;
    }
}
 
// Write
bool writetopo(const TopoShape& s, const string& outfile)
{
    string suffix = outfile.substr(outfile.find_last_of('.') + 1);
    transform(suffix.begin(), suffix.end(), suffix.begin(), [](unsigned char c) {
        return tolower(c);
        });
    // Check the file extension. If it's .stp or .step, call StepDataTool; if it's .brep, call OCCTTool
    if (suffix == "stp" || suffix == "step")
        return STEP::StepDataTool::Write(s, outfile);
    else if (suffix == "brep")
        return OCCTIO::OCCTTool::Write(s, outfile);
    else {
        cout << "Unsupported output file format: " << suffix << endl;
        return false;
    }
}
 
TopoShape combineFaces(TopoShape& shape)
{
    IndexSet<TopoShape> edges, faces;
    TopoExplorerTool::MapShapes(shape, ShapeType::Face, faces);
    TopoExplorerTool::MapShapes(shape, ShapeType::Edge, edges);
    FaceEditor faceEditor;
    // Right side of the fuselage
    {
        // Delete two faces
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[17 - 1]));
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[19 - 1]));
        // Construct a new face based on the given set of edges and an existing face
        // Top
        IndexSet<TopoShape> set;// All edges to be fused
        set.insert(edges[110 - 1]);
        set.insert(edges[111 - 1]);
        set.insert(edges[109 - 1]);
        set.insert(edges[28 - 1]);
        set.insert(edges[27 - 1]);
        faceEditor.BuildFaceFromSurface(shape, set, TopoCast::Face(faces[18 - 1]));
        // Bottom
        IndexSet<TopoShape> setdown;// All edges to be fused
        setdown.insert(edges[114 - 1]);
        setdown.insert(edges[115 - 1]);
        setdown.insert(edges[116 - 1]);
        setdown.insert(edges[35 - 1]);
        faceEditor.BuildFaceFromSurface(shape, setdown, TopoCast::Face(faces[18 - 1]));
    }
    // Left side of the fuselage
    {
        // Delete three faces
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[52 - 1]));
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[26 - 1]));
        faceEditor.DeleteFace(shape, TopoCast::Face(faces[24 - 1]));
        // Construct a new face based on the given set of edges and an existing face
        // Top
        IndexSet<TopoShape> set;// All edges to be fused
        set.insert(edges[233 - 1]);
        set.insert(edges[138 - 1]);
        set.insert(edges[61 - 1]);
        set.insert(edges[60 - 1]);
        set.insert(edges[135 - 1]);
        set.insert(edges[190 - 1]);
        set.insert(edges[137 - 1]);
        faceEditor.BuildFaceFromSurface(shape, set, TopoCast::Face(faces[25 - 1]));
        // Bottom
        IndexSet<TopoShape> setdown;// All edges to be fused
        setdown.insert(edges[130 - 1]);
        setdown.insert(edges[131 - 1]);
        setdown.insert(edges[132 - 1]);
        setdown.insert(edges[53 - 1]);
        faceEditor.BuildFaceFromSurface(shape, setdown, TopoCast::Face(faces[25 - 1]));
    }
    // Unify faces and edges of the shape
    auto result = ShapeFixTool::UpgradeUnifySameDomain(shape);
    writetopo(result, "combineFaces.brep");
    return result;
}
 
 
void sewEdges(TopoShape& shape, const string& filePath, int e1, int e2, double tolerance)
{
    cout << "Applying auto fix (tolerance = " << tolerance << ") to file: " << filePath << endl;
    try {
        // Find all free edges
        IndexSet<TopoShape> edges;
        TopoExplorerTool::MapShapes(shape, ShapeType::Edge, edges);
        IndexSet<TopoShape> list = GeomE::DetectTool::DetectFreeEdges(shape);
        // Sew two edges
        TopoEdge edge1 = TopoCast::Edge(edges[e1]);
        TopoEdge edge2 = TopoCast::Edge(edges[e2]);
        EdgeEditor editor;
        editor.SewEdges(shape, edge1, edge2, tolerance);
    }
    catch (const exception& e) {
        cout << "Auto fix failed for file " << filePath << ". Exception: " << e.what() << endl;
        return;
    }
 
    // Construct the output filename by appending "_autosew" suffix to the original filename
    filesystem::path p(filePath);
    string stem = p.stem().string();
    string extension = p.extension().string();
    extension = ".step";
    string outFile = (p.parent_path() / (stem + "_autosew" + extension)).string();
    // Write
    if (writetopo(shape, outFile))
        cout << "Auto fix succeeded, output saved to: " << outFile << endl;
    else
        cout << "Failed to write output file: " << outFile << endl;
    cout << "success auto fix" << endl;
}
 
TopoShape fillhole_with_newface(TopoShape& shape)
{
    IndexSet<TopoShape> edges, faces;
    TopoExplorerTool::MapShapes(shape, ShapeType::Edge, edges);
    TopoExplorerTool::MapShapes(shape, ShapeType::Face, faces);
    IndexSet<TopoShape> set;
    set.insert(edges[14 - 1]);
    set.insert(edges[16 - 1]);
    set.insert(edges[88 - 1]);
 
    FaceEditor faceEditor;
    // Construct a new face extending from Face 2, using specified edge set. The new face shares the same surface geometry as Face 2.
    faceEditor.BuildFaceFromSurface(shape, set, TopoCast::Face(faces[3 - 1]));
    // Unify faces and edges of the shape
    auto result = ShapeFixTool::UpgradeUnifySameDomain(shape);
    // Write
    writetopo(result, "fillhole_with_newface.step");
    return result;
}
 
 
int main(int argc, char* argv[])
{
    try {
        std::cout << "start work" << endl;
        TopoShape shape;
        readtopo(shape, "./data/helicopter-2025.stp");
        shape = combineFaces(shape);
        sewEdges(shape, "./combineFaces.step", 187 - 1, 247 - 1, 0.007);
        shape = fillhole_with_newface(shape);
        writetopo(shape, "./outshape.brep");
    }
    catch (const std::exception& e) {
        std::cout << "Sorry, there was an exception: " << e.what() << endl;
    }
    catch (...) {
        std::cout << "Unknown exception" << endl;
    }
    system("pause");
    return 0;
}