通过曲面法线所连接的面的角度对其进行加权.这是表面渲染的一种常见做法(请参见此处的讨论: http://www.bytehazard.com/code/vertnorm.html )，并确保您的底面的权重大于两个倾斜的侧面的权重.我不知道Blender是否做不同的事情，但是您应该尝试一下.

Weight the surface normals by the angle of the faces where they join. It is a common practice in surface rendering (see discussion here: http://www.bytehazard.com/code/vertnorm.html), and will ensure that your bottom face is weighted stronger than the two slanted side faces. I don't know if Blender does it differently, but you should give it a try.