When I create a UV sphere and add the subdivision surface modifier, the following wrinkle appears.
How can I avoid it?
I've read the article How to handle distortion at the poles of a UV sphere? but there seems to be no clear solution.
I've used the word 'apply' in the first sentence of the initial version of this question. It's misleading since I want to preserve the modifier without 'applying' it. Rather, what I meant is 'adding' the modifier.
I followed josh sanfelici's solution, but still there is an artifact at the pole.
Here is the screen: (A rendered view with a sun lamp)
Maybe it's the limitation of the general-purpose subdivision modifier.
BTW, when the cast modifier is added after the subdivision modifier, the sphere becomes perfect (even for my original wrinkled sphere). But since I want to edit the resulting sphere (for example, scaling X, Y, etc) while modifier is added but not applied, it's not usable.