这篇博客内容是紧接着上一篇的NX二次开发-使用数学方法计算两个向量之间的夹角(计算顺逆判断锐角还是钝角)

探讨的内容，也是一样的。就是区分夹角是锐角还是钝角，区分方法，就是这个函数UF_VEC3_dot，点乘的值。函数是QQ群的一位网友发的

我不确定用的对不对，用的不对，请底部留言给我。

    //a·b > 0 点乘大于0 两个向量方向基本相同 夹角在0°90°之间
    //a·b = 0 点乘等于0 正交
    //a·b < 0 点乘小于0 两个向量方向基本相反 夹角在90°-180°之间

NX9+VS2012

//NX9_NXOpenCPP_Wizard1

// Mandatory UF Includes
#include <uf.h>
#include <uf_object_types.h>

// Internal Includes
#include <NXOpen/ListingWindow.hxx>
#include <NXOpen/NXMessageBox.hxx>
#include <NXOpen/UI.hxx>

// Internal+External Includes
#include <NXOpen/Annotations.hxx>
#include <NXOpen/Assemblies_Component.hxx>
#include <NXOpen/Assemblies_ComponentAssembly.hxx>
#include <NXOpen/Body.hxx>
#include <NXOpen/BodyCollection.hxx>
#include <NXOpen/Face.hxx>
#include <NXOpen/Line.hxx>
#include <NXOpen/NXException.hxx>
#include <NXOpen/NXObject.hxx>
#include <NXOpen/Part.hxx>
#include <NXOpen/PartCollection.hxx>
#include <NXOpen/Session.hxx>



#include <uf.h>
#include <uf_ui.h>
#include <uf_vec.h>
#include <uf_curve.h>

// Std C++ Includes
#include <iostream>
#include <sstream>

using namespace NXOpen;
using std::string;
using std::exception;
using std::stringstream;
using std::endl;
using std::cout;
using std::cerr;


//------------------------------------------------------------------------------
// NXOpen c++ test class 
//------------------------------------------------------------------------------
class MyClass
{
    // class members
public:
    static Session *theSession;
    static UI *theUI;

    MyClass();
    ~MyClass();

    void do_it();
    void print(const NXString &);
    void print(const string &);
    void print(const char*);

private:
    Part *workPart, *displayPart;
    NXMessageBox *mb;
    ListingWindow *lw;
    LogFile *lf;
};

//------------------------------------------------------------------------------
// Initialize static variables
//------------------------------------------------------------------------------
Session *(MyClass::theSession) = NULL;
UI *(MyClass::theUI) = NULL;

//------------------------------------------------------------------------------
// Constructor 
//------------------------------------------------------------------------------
MyClass::MyClass()
{

    // Initialize the NX Open C++ API environment
    MyClass::theSession = NXOpen::Session::GetSession();
    MyClass::theUI = UI::GetUI();
    mb = theUI->NXMessageBox();
    lw = theSession->ListingWindow();
    lf = theSession->LogFile();

    workPart = theSession->Parts()->Work();
    displayPart = theSession->Parts()->Display();
    
}

//------------------------------------------------------------------------------
// Destructor
//------------------------------------------------------------------------------
MyClass::~MyClass()
{
}

//------------------------------------------------------------------------------
// Print string to listing window or stdout
//------------------------------------------------------------------------------
void MyClass::print(const NXString &msg)
{
    if(! lw->IsOpen() ) lw->Open();
    lw->WriteLine(msg);
}
void MyClass::print(const string &msg)
{
    if(! lw->IsOpen() ) lw->Open();
    lw->WriteLine(msg);
}
void MyClass::print(const char * msg)
{
    if(! lw->IsOpen() ) lw->Open();
    lw->WriteLine(msg);
}


//------------------------------------------------------------------------------
// Do something
//------------------------------------------------------------------------------
void MyClass::do_it()
{

    // TODO: add your code here
    
    UF_initialize();


    //创建直线1
    UF_CURVE_line_t LineCoords1;
    LineCoords1.start_point[0] = 0.0;
    LineCoords1.start_point[1] = 0.0;
    LineCoords1.start_point[2] = 0.0;
    LineCoords1.end_point[0] = 0.0;
    LineCoords1.end_point[1] = 100.0;
    LineCoords1.end_point[2] = 0.0;
    tag_t Line1Tag = NULL_TAG;
    UF_CURVE_create_line(&LineCoords1, &Line1Tag);

    //创建直线2
    UF_CURVE_line_t LineCoords2;
    LineCoords2.start_point[0] = 0.0;
    LineCoords2.start_point[1] = 0.0;
    LineCoords2.start_point[2] = 0.0;
    LineCoords2.end_point[0] = 110.0;
    LineCoords2.end_point[1] = 80.0;
    LineCoords2.end_point[2] = 0.0;
    tag_t Line2Tag = NULL_TAG;
    UF_CURVE_create_line(&LineCoords2, &Line2Tag);


    //直线1的向量方向,终点减起点
    double Vec1[3] = {LineCoords1.end_point[0]-LineCoords1.start_point[0], LineCoords1.end_point[1]-LineCoords1.start_point[1], LineCoords1.end_point[2]-LineCoords1.start_point[2]};

    //直线2的向量方向,终点减起点
    double Vec2[3] = {LineCoords2.end_point[0]-LineCoords2.start_point[0], LineCoords2.end_point[1]-LineCoords2.start_point[1], LineCoords2.end_point[2]-LineCoords2.start_point[2]};

    //求两个向量的叉乘
    double CrossProduct[3];
    UF_VEC3_cross(Vec1, Vec2, CrossProduct);

    //已知两个向量求夹角(输出的是弧度)
    double Angle;
    UF_VEC3_angle_between(Vec1, Vec2, CrossProduct, &Angle);

    //向量点乘
    double dot_product = 0;
    UF_VEC3_dot(Vec1, Vec2, &dot_product);

    //a·b > 0 点乘大于0 两个向量方向基本相同 夹角在0°90°之间
    //a·b = 0 点乘等于0 正交
    //a·b < 0 点乘小于0 两个向量方向基本相反 夹角在90°-180°之间
    double ss22 = RADEG*Angle;
    if (dot_product < 0)
    {
        ss22 = 360 - RADEG*Angle;//角度=180度/π*弧度,或者用宏定义RADEG*弧度
    }


    //打印
    char msg[256];
    sprintf(msg, "%f", ss22);
    uc1601(msg, 1);


    UF_terminate();

}






//------------------------------------------------------------------------------
// Entry point(s) for unmanaged internal NXOpen C/C++ programs
//------------------------------------------------------------------------------
//  Explicit Execution
extern "C" DllExport void ufusr( char *parm, int *returnCode, int rlen )
{
    try
    {
        // Create NXOpen C++ class instance
        MyClass *theMyClass;
        theMyClass = new MyClass();
        theMyClass->do_it();
        delete theMyClass;
    }
    catch (const NXException& e1)
    {
        UI::GetUI()->NXMessageBox()->Show("NXException", NXOpen::NXMessageBox::DialogTypeError, e1.Message());
    }
    catch (const exception& e2)
    {
        UI::GetUI()->NXMessageBox()->Show("Exception", NXOpen::NXMessageBox::DialogTypeError, e2.what());
    }
    catch (...)
    {
        UI::GetUI()->NXMessageBox()->Show("Exception", NXOpen::NXMessageBox::DialogTypeError, "Unknown Exception.");
    }
}


//------------------------------------------------------------------------------
// Unload Handler
//------------------------------------------------------------------------------
extern "C" DllExport int ufusr_ask_unload()
{
    return (int)NXOpen::Session::LibraryUnloadOptionImmediately;
}


阿飞
2021年10月17日