create 3D pie chart or 3D circle

I want to create a 3D pie chart.

Do I have to use OpenGl ES or Core Graphics?

How can I draw a 3开发者_开发问答D pie chart or at least a 3D circle?

Thank you for helping.

I want to create a dynamic chart, so I have to use objective c and xcode.

Each pie chart piece has to be treaten separately. I didn't find any library which I could use.

Definitely 3D pie charts can be created using OPENGLES.

Refer to : Ray's Tutorial

And just you wanna see the REAL implemention: Citibank For iPad® Video

Hope this helps :)

The easiest way is probably using Google Chart API.

Here is an example:

The URL for this is https://chart.googleapis.com/chart?cht=p3&chs=250x100&chd=t:20,30,50&chl=a|b|c

So you would download the image and display it in an UIImageView.