不带对话框的3D旋转图，可以实现多角度的旋转，自己设置角度来进行相应的操作-Figure 3D rotation without dialog, you can achieve multi-angle rotation, set up their own perspective to the corresponding operation

绘制圆环中角度旋转90度的扭曲网格线，圆环外网格线不发生扭曲-Draws a circle Angle rotated 90 degrees in the distorted grid lines, outside the circle is not distorted grid lines