使用QT应用程序，显示一个三维的三角锥（四面体），每个面具有不同的颜色，可单击或拖动鼠标旋转三角坠。双击某个面，可设置该面的颜色。(Using the QT application, it displays a three-dimensional triangular cone (tetrahedron), each mask has a different color, and can click or drag the mouse to rotate the triangle. Double click a surface to set the color of the surface.)