Texture an Object at Runtime, work through help needed.

Hi,

I need suggestions on how to approach texturing an object at runtime like in this example video. Here is the video https://www.youtube.com/watch?v=1DWPb_3IOGA at frame 1:14 the user opens the brushes then selects one notice how he touches the object there is a selection ring then when he releases his finger that portion of the vase gets textured.

The only thing I can come up with would be to model the vase with a lot of materials and add/change a texture to each material at runtime (http://docs.unity3d.com/ScriptReference/Material-mainTexture.html). But as you can see from the image attached I would need to have a lot of materials just to texture the whole vase which does not seem like the right approach for patterning (texturing) this kind of object at runtime.

Although I don't know how Im going to achieve this Id prefer to have one UV texture map at the end (for export) as opposed to per face materials and textures.

Can someone help me work through a solution that might be a better solution?

Sincerely, Michael