opengl中的对象透明度

Question

我创建了一个固定框架，然后绘制了平行六面体。接下来，我创建了另一个框架，它应该是附加到对象的对象框架。在启用深度测试之前，对象框架的轴在原点相交，但平行六面体的颜色似乎发生干扰，一切都变得混乱。例如：物体的正面是红色的，如果我在绘制物体之前不添加深度测试，底部就会变成红色，如下图所示。

当我在绘制对象之前添加深度测试时，颜色是正确的，但对象框架的轴不正确如图所示相交，其中物体的正面为红色。 这是我的主窗口的图片：

这是我的代码：

  void GLWidget::paintGL()
{
    glClear(GL_COLOR_BUFFER_BIT);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);


    glMatrixMode(GL_MODELVIEW);
    
    glLoadIdentity();
    
     gluLookAt(6.0, 6.0, 6.0, 3.0,3.5,0.0, 0.0,1.0,0.0); 
     
     
    glPushMatrix();




    glTranslatef(1.1, 2.1, -3.1);


    glScalef(0.8,0.8,0.8);


  
    glLineWidth(3.0f);

     glBegin(GL_LINES);
     //X_axis
    glColor3f (1.0, 0.0, 0.0);
    glVertex3f(0.0, 0.0, 0.0);
    glVertex3f(4.0, 0.0, 0.0);
    // arrow
    glVertex3f(4.0, 0.0f, 0.0f);
    glVertex3f(3.75, 0.25f, 0.0f);

    glVertex3f(4.0, 0.0f, 0.0f);
    glVertex3f(3.75, -0.25f, 0.0f);
    //Y_axis
    glColor3f (0.0, 1.0, 0.0);
    glVertex3f(0.0, 0.0, 0.0);
    glVertex3f(0.0, 4.0, 0.0);
    // arrow
    glVertex3f(0.0, 4.0f, 0.0f);
    glVertex3f(0.25, 3.75f, 0.0f);

    glVertex3f(0.0, 4.0f, 0.0f);
    glVertex3f(-0.25, 3.75f, 0.0f);

    //Z_axis
    glColor3f (0.0, 0.0, 1.0);
    glVertex3f(0.0, 0.0, 0.0);
    glVertex3f(0.0, 0.0, 4.0);
    // arrow


    glVertex3f(0.0, 0.0f ,4.0f );
    glVertex3f(0.0, 0.25f ,3.75f );

    glVertex3f(0.0, 0.0f ,4.0f );
    glVertex3f(0.0, -0.25f ,3.75f );
    glEnd();

   // rotation about X axis
    glRotatef(x,0.0,0.0,1.0);
    // rotation about Y axis
    glRotatef(y,0.0,1.0,0.0);
    // rotation about Z axis
    glRotatef(z,-1.0,0.0,0.0);
    //glRotatef(90.0f,0.0f,0.1f,0.0f);




   // Draw_Object
   
  glEnable(GL_DEPTH_TEST);

   glBegin(GL_QUADS);                
   // Top (y=1.0)


   glColor4f(0.0f, 1.0f, 0.0f,0.5f);     // Green
   glVertex3f(2.0f, 1.0f, -1.0f);
   glVertex3f(-2.0f, 1.0f, -1.0f);
   glVertex3f(-2.0f, 1.0f, 1.0f);
   glVertex3f(2.0f, 1.0f, 1.0f);

  // Bottom face (y = -1.0f)

   glColor4f(1.0f, 0.5f, 0.0f,0.5f);     // Orange
   glVertex3f(2.0f, -1.0f, 1.0f);
   glVertex3f(-2.0f, -1.0f, 1.0f);
   glVertex3f(-2.0f, -1.0f, -1.0f);
   glVertex3f(2.0f, -1.0f, -1.0f);

   // Front face  (z = 1.0f)

   glColor4f(1.0f, 0.0f,0.0f,0.5f);     // Red
   glVertex3f(2.0f, 1.0f, 1.0f);
   glVertex3f(-2.0f, 1.0f, 1.0f);
   glVertex3f(-2.0f, -1.0f, 1.0f);
   glVertex3f(2.0f, -1.0f, 1.0f);

   // Back face (z = -1.0f)

   glColor4f(1.0f, 1.0f, 0.0f,0.5f);     // Yellow
   glVertex3f(2.0f, -1.0f, -1.0f);
   glVertex3f(-2.0f, -1.0f, -1.0f);
   glVertex3f(-2.0f, 1.0f, -1.0f);
   glVertex3f(2.0f, 1.0f, -1.0f);

   // Left face (x = -1.0f)

   glColor4f(0.0f, 0.0f, 1.0f,0.5f);     // Blue
   glVertex3f(-2.0f, 1.0f, 1.0f);
   glVertex3f(-2.0f, 1.0f, -1.0f);
   glVertex3f(-2.0f, -1.0f, -1.0f);
   glVertex3f(-2.0f, -1.0f, 1.0f);

   // Right face (x = 1.0f)

   glColor4f(1.0f, 0.0f, 1.0f,0.5f);     // Purple
   glVertex3f(2.0f, 1.0f, -1.0f);
   glVertex3f(2.0f, 1.0f, 1.0f);
   glVertex3f(2.0f, -1.0f, 1.0f);
   glVertex3f(2.0f, -1.0f, -1.0f);
   glEnd();

   glFlush();



 // Object_frame
   glRotated(-90,0.0,1.0,0.0);
   glBegin(GL_LINES);
   glColor3f (1.0, 0.0, 0.0);
   glVertex3f(0.0, 0.0, 0.0);
   glVertex3f(4.0, 0.0, 0.0);
   // arrow
   glVertex3f(4.0, 0.0f, 0.0f);
   glVertex3f(3.75, 0.25f, 0.0f);

   glVertex3f(4.0, 0.0f, 0.0f);
   glVertex3f(3.75, -0.25f, 0.0f);

   glColor3f (0.0, 1.0, 0.0);
   glVertex3f(0.0, 0.0, 0.0);
   glVertex3f(0.0, 4.0, 0.0);
   // arrow
   glVertex3f(0.0, 4.0f, 0.0f);
   glVertex3f(0.25, 3.75f, 0.0f);

   glVertex3f(0.0, 4.0f, 0.0f);
   glVertex3f(-0.25, 3.75f, 0.0f);

   glColor3f (0.0, 0.0, 1.0);
   glVertex3f(0.0, 0.0, 0.0);
   glVertex3f(0.0, 0.0, 4.0);

   // arrow
   glVertex3f(0.0, 0.0f ,4.0f );
   glVertex3f(0.0, 0.25f ,3.75f );

   glVertex3f(0.0, 0.0f ,4.0f );
   glVertex3f(0.0, -0.25f ,3.75f );
   glEnd();