Calculating bounding shape of group of elements without corners

[thornag]

Hi guys,

First just wanted to say Hi to everyone here.

I have a little problem with not so much execution but an idea with how to calculate a 'bounding shape' for a group of objects.

!http://screenshu.com/static/uploads/temporary/z5/8n/4r/pyfuei.jpg(Before)!

So in the above example you can see a graphicView, graphicScene and a group of selected graphicItems

Now, I can possibly work out what is the bounding polygon of this by looping through selection and comparing points/areas, but what I would love to get is something similar to

!http://screenshu.com/static/uploads/temporary/6u/34/m3/4hmhd8.jpg(After)!

So I want a shape that surrounds my selection but has no corners.

Any pointing towards the right direction much appreciated.

Cheers
Michael