# Creating a surface inside a Volume **URL:** \ **Category:** General Discussion\ **Created:** [January 26, 2021, 3:45pm UTC](https://community.freefem.org/t/creating-a-surface-inside-a-volume/761 "2021-01-26T15:45:36Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Mik](https://avatars.discourse-cdn.com/v4/letter/m/958977/32.png) [@Mik](https://community.freefem.org/u/Mik)\ **Post date:** [January 26, 2021, 3:45pm UTC](https://community.freefem.org/t/creating-a-surface-inside-a-volume/761/1 "2021-01-26T15:45:37Z")
Dear Community, I would like to know if we can create a surface inside a volume to impose some conditions on it such as an adiabatic one. ![Capture|690x294] I have attached an image to illustrate. So for the 1st iteration, I would like to have “1” as my adiabatic surface (the dotted one) and for iteration “2” the next part; so on and so forth. Thanks in advance for your help. ![Capture](https://canada1.discourse-cdn.com/flex030/uploads/freefem/original/1X/6ef9181a6584de2346efbc1c8466ded6ea431ba9.png) Sincerely ---
**Author:** ![frederichecht](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/frederichecht/32/15_2.png) [@frederichecht](https://community.freefem.org/u/frederichecht)\ **Post date:** [January 29, 2021, 7:45pm UTC](https://community.freefem.org/t/creating-a-surface-inside-a-volume/761/2 "2021-01-29T19:45:28Z")
You can build 3d mesh with internal boundary, but to add adiabatic condition (du/dn)=0 on this internal surface is not so easy, I have no simple idea to that. ---
**Author:** ![Mik](https://avatars.discourse-cdn.com/v4/letter/m/958977/32.png) [@Mik](https://community.freefem.org/u/Mik)\ **Post date:** [February 25, 2021, 7:49am UTC](https://community.freefem.org/t/creating-a-surface-inside-a-volume/761/3 "2021-02-25T07:49:55Z")
Thank you with the internal boundary everything is working well.