title: Box2d custom shape or bodies joint
body: <p>Let's say i want to create simple physics object with a shape of "<a href="https://www.google.co.il/search?q=matryoshka&amp;rlz=1C1CHMO_iwIL531IL531&amp;aq=f&amp;um=1&amp;ie=UTF-8&amp;hl=en&amp;tbm=isch&amp;source=og&amp;sa=N&amp;tab=wi&amp;ei=z2GDUejfAoHjswaw_ICwBw&amp;biw=1280&amp;bih=923&amp;sei=0mGDUenDB47ItAb32YFQ" rel="nofollow">matryoshka</a>" or banal snowman . As i see it , i have two options to do it: <br />1. To create 2 circle  (or may be custom) bodies and connect them with weld joint , or<br /> 2. To create one body with two circle (or may be custom) shapes in it. <br/><br/>
  So the question is: what is more expensive for CPU: bodies connected with joints or complicate-shaped bodies. If i have one object may be i don't feel difference in performance , but what if i have many object of that type? <br/>
  I know that joints are expensive , but may be custom shaped bodies is more expensiver?
  I'm working with Box2dFlash.</p>