"Smoothing Groups"

Hi everybody,

the search function could not help me, but maybe I was just looking for the wrong words.
In 3ds max there are “smoothing groups” which define which faces are smoothed together and which not. I am looking for that kind of feature in Blender, but could not find it yet.
On the screenshot you see what I want to do: I want the faces of the green area being smoothed, and the faces of the blue area, too. But the two areas should not be smoothed together. I want a sharp edge where the two areas meet (red line).

Is there any way to do that?

Thanks in advance,


It’s called edgesplit modifier in blender. It actually works by physically splitting the mesh into separate parts, something you may notice if you put other modifiers below it, but the effect is precisely what you need. You can control it by making edges sharp through the ctrl+e menu in edit mode. It can also split edges that exceed a certain angle automatically.

There are actually several ways to do that in Blender. Let me just say that 3dsmax’s smoothing groups are great and there is not a similar way to do that in Blender, the techniques to do it are somewhat different and require practice. Try them out:

  1. Refine the model by adding more edges to it and then applying a SubSurf modifier. This way is probably the worst one, because it fills up the model with polys and is not as sharp as it should probably be.

  2. Select the polys you want smoothed and go CTRL+F followed by Shade Smooth or Shade Flat. This doesn’t work perfect sometimes.

  3. Third way is probably the best for you, the EdgeSplit modifier. Select all polys and Shade Smooth all. Select the edges you want sharp and go CTRL+E followed by Mark Sharp. If you make a mistake, use CTRL+Z or the Clear Sharp option. Then apply the EdgeSplit modifier and check the Sharp Edges option.

Thank you guys!
Fast and detailed answers, like almost always in this forum. :slight_smile:
I tried the EdgeSplit modifier and in Blender the result is exactly what I was looking for!
As the model will be used in Flash, I hope that this edge splitting does not “destroy” the mesh too much for export.

Don’t worry, smoothing groups is also essentially a way of telling the graphics card where to split the mesh so that the shading is correct

That’s right. But if that’s true, is Blender duplicating vertices in order to smooth faces correctly?

Only if you apply the modifier. If you export the model as an obj for example you will have to apply this modifier to keep the same effect in any external application. If you then remove double vertices you will lose the effect.

Thanks for sharing that info.