How on earth did I manage to smooth this?:D Could anyone explain?

Hi, hopefully I’m posting this in the right place. So I was trying to model a Doric column in Blender. I’m a beginner with the program, there’s a lot I still don’t understand. This was the rough mesh that was supposed to be the capital:[ATTACH=CONFIG]273423[/ATTACH][ATTACH=CONFIG]273424[/ATTACH]
Basically it’s modeled from a 20-facet cylinder. The next step was to smooth it out so it would look the part. I looked up ways to do this and found several tutorials, but when I applied those instructions the result wasn’t what I needed. The 2 methods I tried were Shading Smooth+Edge Split modifier (left), which left the mesh still visibly faceted, and Shading Smooth+Subsurf modifier (right), which smoothed out the edges around the top and bottom which should have been left sharp.

Then, on a gut feeling that was absolutely serendipitous, I set Shading Smooth, applied the Edge Split Modifier and then applied a Multiresolution modifier with 4 level Subdivide, and got exactly what I wanted all along! Namely this:

So ShadingSmooth+EdgeSplit+Multires worked, but I have no idea why. I’d like to ask, why did this combination work in this situation and the first 2 didn’t? What do edgesplit, subsurf and multires do differently? It’s all so confusing to me, if you have the time please enlighten me!

Here’s what each modifier does

Smooth shading makes no change to the mesh itself, it is just a cosmetic smoothing between faces.

Multires and Subsurf modifiers will give the same effect in your case. The multires lets you change the mesh as each subdivision level and is used with the sculpting tools

You don’t have to apply modifiers to give the same effect. This gives you non destructive changes to your mesh. Only apply if you need to.

The order of modifiers is important. They are applied to your mesh from the top to the bottom in the modifier stack. Chnging the order can give you different results.

In this case adjacent faces with an angle >20 degree are physically split from each other and then those split faces are subdivided

In particular, using EdgeSplit followed by Subsurf works well enough for this simple case, but it is a fragile combination, and can easily lead to gaps in the final mesh.

It’s safer to put the Subsurf before the EdgeSplit, and use creases to prevent the edges you want sharp being rounded by the subsurf.

EdgeSplit is primarily a shading control tool, not a modelling tool.

Best wishes,

The “problem” is that you have an Ngon at the top of your mesh. Ngons don’t work well with the Subsurf modifier if they aren’t on an absolutely flat surface or if their contour is at an edge of the shape.

Easy fix: Select the Ngon and press [I] to inset. It will create a ring of quads all around the Ngon and isolate it from the edge of your shape.

Wow, thanks everybody for taking the time to explain this to me, means a lot! As I said I’m a complete beginner still struggling to make sense of the program:D Thanks again