Add creases to sharpen mesh edges.
You can add creases to mesh objects that have a smoothing level of 1 or higher.
The result of creasing differs, depending on what type of subobject you select.
As you apply a crease, you set a crease value that determines how the crease is affected by smoothing. A value of Always ensures that the crease is always retained, even when the mesh is repeatedly smoothed. Higher crease values ensure that the crease is retained through several smoothing processes. (During smoothing, the assigned crease value is decreased by the value of the original level of smoothing.)
You can add a crease to a mesh that has not been smoothed. However, the effect is not visible unless you smooth the object.
You can restore a crease to a smoothed state that corresponds to the smoothing level for the object. If you remove a crease that is adjacent to other creased subobjects, their contours are adjusted.