# Is it possible to customize smooth geometry for a Bezier curve?

There is a curve. In the settings of its geometry, we make Bevel, creating a volume with some kind of profile (in the example on the screenshots, the type is simply Round). Also, assign different radii to the vertices, varying the thickness of the shape. Unfortunately, as a result, the geometry on the circle around the vertex is angular. And here is the question: is it possible to somehow achieve a smooth exit of geometry from the vertices, and not a sharp decline or rise? (as in the second screen, green outline)

It's a bit angular because of the interpolation method of the radius. But you can change that in properties/object data/active spline/radius:

4 identical curves. I like Cardinal or Ease interpolation here.

Another option here, for even more control, is to specify a taper curve, in properties/object data/geometry/taper object rather than using radius.

• what I need! thanks a lot! Dec 25, 2021 at 8:27
• cardinal is the best Dec 25, 2021 at 8:30

I'm not 100% sure but I think if you use NURBS curves instead then this problem goes away.

• Nurbs in Blender are a little more complicated than in Rhino (which I had to model in), and I find it difficult to manage them. Also, I need to snap to the vertices of the bezier curve, it's easier here. I still need bezier curves. But now I understand that in Blender the creation of the volume-envelope is done according to the linear loft algorithm. Not by the tangent formula. Dec 24, 2021 at 12:10

You can have finer control over the beveling with geometry nodes. Add a geometry nodes modifier on your curve and use these nodes. Tweak the float curve node to change the bevel profile. You may need to change the resampling value for more accuracy as well.

• I am not very familiar with the node system, but thanks for the advice, I will study Dec 24, 2021 at 12:17