平滑着色与平直着色

Note

Both Shade Smooth and Flat are also available in Object Mode and function the same way.

Reference

Mode

Face ‣ Shade Smooth

Using interpolated vertex normals, the mesh faces will blur at the edges and appear smooth.

平直着色

Reference

Edit Mode

Face ‣ Shade Flat

Face normals are displayed evenly, because of this all the edges of the selected mesh will be easily visible.

Use the Edge Split modifier and within the mesh data properties to balance between smooth surfaces and sharp edges.