NX8.5,二次开发,用UG/Open API函数结合C++ 写一个OBB算法，获取对象的最小包容盒

好的，下面是一个简单的UG/Open API函数结合C++写的OBB算法获取对象的最小包容盒的示例代码：

// UG/Open API头文件
#include <NXOpen/NXOpenAPI.hxx>
#include <NXOpen/Body.hxx>
#include <NXOpen/BodyCollection.hxx>
#include <NXOpen/DisplayManager.hxx>
#include <NXOpen/Part.hxx>
#include <NXOpen/PartCollection.hxx>
#include <NXOpen/Point.hxx>
#include <NXOpen/Point3d.hxx>
#include <NXOpen/Vector.hxx>
#include <NXOpen/Unit.hxx>
// C++头文件
#include <vector>
#include <algorithm>

using namespace NXOpen;

// 计算最小包容盒主函数
void computeOBB(Body* body, Point3d& center, Vector& direction, double& length, double& width, double& height) {
    // 获取体积信息
    double volume, cgx, cgy, cgz, ixx, iyy, izz, ixy, ixz, iyz;
    body->ComputeVolumeProperties(volume, cgx, cgy, cgz, ixx, iyy, izz, ixy, ixz, iyz);
    // 计算质心
    center = Point3d(cgx, cgy, cgz);
    // 计算惯性主轴
    Matrix3x3 inertiaMatrix(ixx, ixy, ixz, ixy, iyy, iyz, ixz, iyz, izz);
    std::vector<double> eigenvalues;
    std::vector<Vector> eigenvectors;
    inertiaMatrix.ComputeEigenvaluesAndEigenvectors(eigenvalues, eigenvectors);
    direction = eigenvectors[0];
    // 计算长度、宽度和高度
    std::vector<Point3d> points;
    body->AskPoints(points);
    std::vector<double> projections;
    for (std::vector<Point3d>::const_iterator iter = points.begin(); iter != points.end(); ++iter) {
        Vector v = Vector(center, *iter);
        projections.push_back(v.Dot(direction));
    }
    std::sort(projections.begin(), projections.end());
    length = projections.back() - projections.front();
    width = 0.0;
    height = 0.0;
    for (std::vector<Point3d>::const_iterator iter = points.begin(); iter != points.end(); ++iter) {
        Vector v = Vector(center, *iter);
        double projection = v.Dot(direction);
        Vector projectionVector = direction * projection;
        Vector orthogonalVector = v - projectionVector;
        width += orthogonalVector.Magnitude();
        height += projectionVector.Magnitude();
    }
    width /= static_cast<double>(points.size());
    height /= static_cast<double>(points.size());
}

// 主函数
int main() {
    // 打开当前工作部件
    Part* part = dynamic_cast<Part*>(Session::GetSession()->Parts()->Work());
    if (!part) {
        std::cerr << "No active part found." << std::endl;
        return 1;
    }
    // 获取当前选择的实体
    Selection::Instance()->SetPickFilterMaskBits(Selection::FilterObjectBody);
    Selection::Instance()->SetSelectionLimits(1, 1);
    Selection::Instance()->Clear();
    int response = Selection::Instance()->SelectObjects("Select a body:");
    if (response != UF_UI_SEL_SUCCESS) {
        std::cerr << "Selection failed." << std::endl;
        return 1;
    }
    std::vector<TaggedObject*> selectedObjects = Selection::Instance()->GetSelectedObjects();
    if (selectedObjects.empty()) {
        std::cerr << "No object selected." << std::endl;
        return 1;
    }
    Body* body = dynamic_cast<Body*>(selectedObjects[0]);
    if (!body) {
        std::cerr << "Selected object is not a body." << std::endl;
        return 1;
    }
    // 计算最小包容盒
    Point3d center;
    Vector direction;
    double length, width, height;
    computeOBB(body, center, direction, length, width, height);
    // 输出结果
    std::cout << "Center: (" << center.X() << ", " << center.Y() << ", " << center.Z() << ")" << std::endl;
    std::cout << "Direction: (" << direction.X() << ", " << direction.Y() << ", " << direction.Z() << ")" << std::endl;
    std::cout << "Length: " << length << std::endl;
    std::cout << "Width: " << width << std::endl;
    std::cout << "Height: " << height << std::endl;
    // 显示结果
    DisplayManager* dm = part->DisplayManager();
    Marker* centerMarker = dm->CreateMarker(center, Marker::MarkerTypeDisc, 5.0, Color::Orange, "Center", true, false);
    Arrow* directionArrow = dm->CreateArrow(center, center + direction * length * 0.5, Arrow::ArrowheadStyleFilled, 2.0, 0.5, Color::Blue, "Direction", true, false);
    Box* box = dm->CreateBox(center, direction, length, width, height, Color::Green, "OBB", true, false);
    return 0;
}

这个示例代码中，OBB算法的主要计算过程在`computeOBB`函数中实现。该函数以一个`Body`指针作为输入参数，计算出该实体的最小包容盒的中心点、方向、长度、宽度和高度，并将这些结果保存在输出参数中。主函数中，我们通过用户交互选择一个实体，然后调用`computeOBB`函数计算最小包容盒，最后输出结果并在图形窗口中显示最小包容盒。