저는 XY32와 Z가있는 사각형 그리드를 그리기 위해 Opentk를 사용하여 마우스

Question

을 사용하여 평면에서 점을 선택하는 방법을 사용하여 3 차원 평면을 얻었습니다. 이제 레이 캐스팅 방법을 사용하여 그리드에서 점을 선택하는 방법을 설명합니다. 마우스 좌표와 관련하여 사각형에 점을 어떻게 얻을 수 있습니까? 도움이 될 것입니다.

// Replaces gluPerspective. Sets the frustum to perspective mode. 
    // fovY  - Field of vision in degrees in the y direction 
    // aspect - Aspect ratio of the viewport 
    // zNear - The near clipping distance 
    // zFar  - The far clipping distance 
    void perspectiveGL(double fovY, double aspect, double zNear, double zFar) 
    { 
     const double pi = 3.1415926535897932384626433832795; 
     double fW, fH; 
     fH = System.Math.Tan((fovY/2)/180 * pi) * zNear; 
     fH = System.Math.Tan(fovY/360 * pi) * zNear; 
     fW = fH * aspect; 
     GL.Frustum(-fW, fW, -fH, fH, zNear, zFar); 
    } 

이것은

private void m_OpenTKGLControl_DrawingArea_Paint(object sender, PaintEventArgs e) 
    { 
     if (!loaded) // Play nice 
      return; 

     GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit | ClearBufferMask.StencilBufferBit); 
     GL.LoadIdentity(); 

     GL.Translate(0, 0, -zoom); 
     GL.Translate(tx, ty, 0); 
     GL.Rotate(rotx, 1, 0, 0); 
     GL.Rotate(roty, 0, 1, 0); 


     //if (m_pointT_current_cursor.X < 100) 
     { 
      GL.PushMatrix(); //set where to start the current object transformations 
      GL.Color3(1.0, 1.0, 0); 
      GL.Begin(BeginMode.Lines); 
      GL.Vertex3(0.0, 0.0, 0.0); 
      GL.Vertex3(0.0, 0.0, 10.0);//x axis 
      GL.End(); 
      GL.PopMatrix(); 
     } 

     double grid_width = 10.0; 


     // Draw a white grid "floor" for the tetrahedron to sit on. 
     GL.Color3(Color.FromArgb(68, 68, 68)); 
     GL.Begin(BeginMode.Lines); 

     for (double i = -grid_width/2.0; i <= grid_width/2.0; i += 1.0) 
     { 
      if (i != 0.0) 
      { 
       GL.Vertex3(i, 0.0, grid_width/2.0); GL.Vertex3(i, 0.0, -grid_width/2.0); 
       GL.Vertex3(grid_width/2.0, 0.0, i); GL.Vertex3(-grid_width/2.0, 0.0, i); 
      } 
     } 
     GL.End(); 

     GL.Color3(1.0, 0, 0); 
     GL.Begin(BeginMode.Lines); 
     GL.Vertex3(-grid_width/2.0, 0, 0); GL.Vertex3(grid_width/2.0, 0, 0);//x axis 
     GL.End(); 

     GL.Color3(0, 1.0, 0); 
     GL.Begin(BeginMode.Lines); 
     GL.Vertex3(0, -grid_width/2.0, 0); GL.Vertex3(0, grid_width/2.0, 0);//y axis 
     GL.End(); 

     GL.Color3(0, 0, 1.0); 
     GL.Begin(BeginMode.Lines); 
     GL.Vertex3(0, 0, -grid_width/2.0); GL.Vertex3(0, 0, grid_width/2.0);//z axis 
     GL.End(); 

     GL.Begin(BeginMode.Points);  // Draw The Cube Using quads 
     for (int i = 0; i < m_list_point_cloud.Count(); i++) 
     { 
      GL.Color3(Color.FromArgb(m_list_point_cloud[i].RED, m_list_point_cloud[i].GREEN, m_list_point_cloud[i].BLUE)); // Color 
      GL.Vertex3(m_list_point_cloud[i].X, m_list_point_cloud[i].Y, m_list_point_cloud[i].Z); 
      GL.PointSize(1); 
     } 
     GL.End();   // End Drawing The Point cloud 

     GL.Flush(); 

     m_OpenTKGLControl_DrawingArea.SwapBuffers(); 
    } 

마지막이 부하의 함수 인 glcontrol의 페인트 기능입니다 :

private void SetupViewport() 
    { 
     int w = m_OpenTKGLControl_DrawingArea.Width; 
     int h = m_OpenTKGLControl_DrawingArea.Height; 

     // prevent divide by 0 error when minimised 
     if (w == 0) 
      h = 1; 

     GL.Viewport(0, 0, w, h); 
     GL.MatrixMode(MatrixMode.Projection); 
     GL.LoadIdentity(); 
     perspectiveGL(45, (double)w/h, 0.1, 10000); 
     GL.MatrixMode(MatrixMode.Modelview); 
     GL.LoadIdentity(); 
    } 

이것은 관점의 기능입니다 : 다음과 같이

뷰포트입니다 glcontrol 용

private void m_OpenTKGLControl_DrawingArea_Load(object sender, EventArgs e) 
    { 
     loaded = true; 
     GL.CullFace(CullFaceMode.Back); 
     GL.ClearColor(Color.FromArgb(57, 57, 57)); 
     GL.ClearDepth(1.0); // Enables Clearing Of The Depth Buffer 
     GL.DepthFunc(DepthFunction.Lequal); // The Type Of Depth Test To Do 
     GL.Enable(EnableCap.DepthTest); // Enables Depth Testing 
     GL.Enable(EnableCap.Multisample); 
     GL.ShadeModel(ShadingModel.Smooth); // Enables Smooth Color Shading 
     GL.Hint(HintTarget.PerspectiveCorrectionHint, // Really Nice Perspective Calculations 
       HintMode.Nicest); 

     SetupViewport(); 
    } 

Answer 1

다음은 c가 약간 변경된 코드입니다. 출처 : {https://sites.google.com/site/vamsikrishnav/gluunproject}

#include <GL/glut.h> 
#include <GL/glu.h> 
#include <GL/gl.h> 

#define HEIGHT 580 
#define WIDTH 1000 

double objx = 0, objy=0, objz=0; 

/*THE FUNCTION TO DRAW THE STUFF ON THE SCREEN*/ 
void display() 
{ 
    glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT); 

    glPushMatrix(); 
    //glScalef(2.0f,2.0f,2.0f); 
    glRotatef(90,1.0f,3.0f,2.0f); //rotating object continuously by 2 degree 
    //The big green floor like polygon 
    glBegin(GL_POLYGON); 
    glColor3f(0, 1, 0); 
    glVertex3f(-100, 0, 100 ); 
    glVertex3f(-100, 0, -100 ); 
    glVertex3f(100, 0, -100); 
    glVertex3f(100, 0, 100); 
    glEnd(); 
    glPopMatrix(); 

    //The red cube to be drawn at clicked position 
    glPushMatrix(); 
     glColor3f(1, 0, 0); 
     glTranslatef(objx, objy, objz); 
    glRotatef(90,1.0f,3.0f,2.0f); //rotating object continuously by 2 degree 
     glutSolidTeapot(10); 
    glPopMatrix(); 

    glFlush(); 
    glutSwapBuffers(); 
} 

void mouse(int button, int state, int x, int y) 
{ 
    double modelview[16], projection[16]; 
    int viewport[4]; 
    float z = 1; 

    /*Read the projection, modelview and viewport matrices 
    using the glGet functions.*/ 
    glGetDoublev(GL_PROJECTION_MATRIX, projection); 
    glGetDoublev(GL_MODELVIEW_MATRIX, modelview); 
    glGetIntegerv(GL_VIEWPORT, viewport); 

    //Read the window z value from the z-buffer 
    glReadPixels(x, viewport[3]-y, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &z); 

    //Use the gluUnProject to get the world co-ordinates of 
    //the point the user clicked and save in objx, objy, objz. 
    gluUnProject(x, viewport[3]-y, z, modelview, projection, viewport, &objx, &objy, &objz); 
} 
void keyboard(unsigned char key, int x, int y) 
{ 
} 

void init(int width, int height) 
{ 
     glViewport(0, 0, width, height); 
     glMatrixMode(GL_PROJECTION); 
     glLoadIdentity(); 
     gluPerspective(45, 1.33, 0.1, 400); 
     glMatrixMode(GL_MODELVIEW); 
     glLoadIdentity(); 
     gluLookAt(0, 100, 200, 0, 0, 0, 0, 1, 0); 
} 

int main(int argc, char **argv) 
{ 
     glutInit(&argc, argv); 
     //The most important part specify the things your 
     //glut window should provide 
     glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); 
     glutInitWindowSize(640, 480); 
     glutCreateWindow("HI"); 

     glClearColor(0, 0, 0, 0); 
     //enable z buffer 
     glEnable(GL_DEPTH_TEST); 
     //set the value in z-buffer as 1.0 
     glClearDepth(1.0); 
     init(640, 480); 
     glutDisplayFunc(display); 
     glutReshapeFunc(init); 
     glutIdleFunc(display); 
     glutMouseFunc(mouse); 
     glutKeyboardFunc(keyboard); 
     glutMainLoop(); 
}