In Part 2, we saw how to bevel all edges of an object non-destructively. But what if we don’t want to bevel all edges the same amount? In Blender, bevelling with a modifier has a few controls, which will allow more targeted beveling. There are two main methods.
- First, you can bevel only edges that are of a certain angle. What I mean is you can bevel an edge made from the join of two faces which are a certain angle from each other.
- The second method assigns a certain weight to a particular edge. This weight acts as a factor that multiplies the total bevel amount.
The following image shows an object with edges made from faces of different angles to one another. Construct something similar to follow along:
If we now add a bevel modifier to this object, nothing appears to happen.
We can change the values of Amount, Segments or Angle until we are blue in the face and nothing happens! Nothing happens because Blender stops bevelling the moment the segments begin to overlap. Looking carefully at the object, you will see that four faces connect down to a single vertex on the right-hand side. Any Blender Bevelling close to that vertex will start overlapping, so Blender stops. To override this, we expand the Geometry drop-down in the Modifier Panel and uncheck Clamp Overlap:
Blender Bevelling – The Angle Method
Now we can play with the modifier. Adjusting the Amount and the Segments values directly affects the appearance of the Bevel.
However, it gets really interesting when we change the Angle value in the Blender bevel modifier.
- Above 90-degrees, no bevelling happens.
- Just below 90-degrees, only the side edges are bevelled.
- Below 40-degrees, the edges on the upper surfaces are bevelled
- Below 11-degrees, even the vertical edges with a very small bend are finally bevelled.
So we see that the Angle value of the Bevel Modifier determines which edges get bevelled depending on the angle of the bend. In cases where no bevels are leading towards a single vertex, the Clamp Overlap checkbox is usually left checked to ensure that our bevel amount does not get too large and begin overlapping, leading to all kinds of trouble.
Blender Bevelling – The Weight Method
If we want to target our edges even more specifically, then we go back to the Bevel modifier and change the Limit Method to Weight:
Any Bevelling on our object disappears. Now we go into edit mode 
and change to Edge Select 
.
Let’s say we want to bevel the upper 45-degree edge a large amount and the adjacent 40-degree edge to only half that. All other edges should remain un-bevelled.
Select the 45 degree edge:
Right-click 
and select Edge Bevel Weight from the Edge Context Menu that pops up:
A dotted line appears joining the middle of the edge to the mouse cursor. Moving the mouse doesn’t seem to do anything.
Left-click 
in the viewport and the Edge Bevel Weight Parameter panel appears in the lower-left side of the viewport.
Change its value to 1.000 :
Look at the object and you will see that the edge has acquired a bevel. In the modifier, adjust the Amount so that the Blender Bevel is quite large, say 0.4m :
Now we repeat the procedure for the 40-degree edge:
Right-click and select Edge Bevel Weight from the Edge Context Menu
A dotted line appears, joining the middle of the edge to the mouse cursor.
This time a bevel appears. Move the mouse until the bevel is approximately half the size of the first Bevel, and left-click.
Change to Object mode :
In the Object Data Properties tab check the Auto Smooth checkbox:
Then Right-click the viewport and select Shade Smooth: 
Similarly, any edge can be bevelled non-destructively by modifying its Bevel Weight.
- A weight of 1 means that the Amount parameter in the bevel modifier panel is implemented by a factor of 1 – i.e., 100%.
- A weight of 0.25 means that the bevel on this edge will only have a “strength” of 25% of the Amount parameter – a quarter of the size possible.
- A weight of 0 (the default) means that the bevel size will be infinitely small i.e., no bevel at all.