# Physics libraries, bodies inside bodies
**URL:** https://discourse.processing.org/t/physics-libraries-bodies-inside-bodies/24073
**Category:** Libraries
**Created:** [September 23, 2020, 7:52am UTC](https://discourse.processing.org/t/physics-libraries-bodies-inside-bodies/24073 "2020-09-23T07:52:58Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@opheliagame](https://discourse.processing.org/u/opheliagame)
#### Post date: [September 23, 2020, 7:52am UTC](https://discourse.processing.org/t/physics-libraries-bodies-inside-bodies/24073/1 "2020-09-23T07:52:58Z")
I want to make a simulation that has bodies inside bodies. The only way I have been able to achieve this is by making blobby bodies by Daniel Shiffman and then making new bodies inside the blob. How could I try to make more rigid structures, such that other smaller bodies can be contained inside it? Should I be combining Constant volume joint with distance joints…?
Or is there another library that I could try out
Thanks 🙂
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### Author:  [@solub](https://discourse.processing.org/u/solub)
#### Post date: [September 24, 2020, 1:22pm UTC](https://discourse.processing.org/t/physics-libraries-bodies-inside-bodies/24073/2 "2020-09-24T13:22:10Z")
Hi @opheliagame,
Would you mind being a little bit more specific ? Maybe providing a hand-drawing or a diagram of what you have in mind ?
Am I correct in understanding that you would like to have rigid bodies (as 2D polygons) whose shape is preserved when colliding with each other ? And having the possibility to create other rigid bodies inside of a larger one ?
My first guess would be to try with the Fisica library using the [FPoly()](http://www.ricardmarxer.com/fisica/reference/fisica/FPoly.html) class or with any other library that deals with rigid bodies (like Box2D). I can think of other workarounds but not sure it would work in your case.
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### Author:  [@opheliagame](https://discourse.processing.org/u/opheliagame)
#### Post date: [September 25, 2020, 11:40am UTC](https://discourse.processing.org/t/physics-libraries-bodies-inside-bodies/24073/3 "2020-09-25T11:40:57Z")
Hi @solub Thank you for replying 🙂
Yes exactly, I do want rigid bodies inside other rigid bodies. This term did not strike me while posting the question.
I did think about creating shapes that have a hole, but I am not sure of how to go about this with respect to the vertices. I did now know about the Fisica library before, so will definitely check that out!
The simulation I have in mind is pretty simple in concept, I just want some smaller bodies inside a bigger body. And as a second step, packing the bigger body’s inner volume with the smaller bodies.