# Cone shape smoothening

Hi,

I am trying to render the green cone shaped hats as you can on the pictures above, but there are weird stripes around it

I followed youtube instructions and did turn on auto smooth (30 degrees) under 'Normals' section, but it does not seem to work at all

What am I missing out and what other ways would you recommend? Thanks :)

The smoothing algorithm fakes normals across polygons with a linear interpolation across the triangles into which they are divided for rendering, between the vertex normals at the triangles' corners. Asking that interpolation to simulate the curvature of a surface when the triangles are very long and thin is, literally, a bit of a stretch.

To give smoothing a chance, it's better to have those triangles approach equilateral as closely as possible, and to have smooth transitions between the sizes of faces, where you want smooth transitions between interpolated normals.

Just CtrlShiftB bevelling the vertex at the point a tiny amount, CtrlB bevelling the base perimeter a bit, with 2 segments and a profile of 1, and CtrlR cutting some edge-loops around the cone, as above. gives the smoothing algorithm more to chew on:

If you're getting really fanatical, you can delete the N-gon at the tip, and CtrlF Face menu > Grid Fill it, putting a couple more edge loops in there to aid the transition:

.. and even Catmull-Clark Subdivide the result... It depends on how far you want to go.

• Hi, sorry for the late accept, thank you for the detailed answer!! :) Dec 20 '20 at 5:37

Try selecting the hat object and choosing Shade Smooth from the Object Context Menu (Right-click, or W key) then Auto-Smooth Normals should function as intended.

You can also set individual faces to have smooth shading in Edit Mode, using the Face Context Menu.