# Unioning/subtracting/slicing/shell bodies should not be a lossy operation

**URL:** <https://discourse.shapr3d.com/t/unioning-subtracting-slicing-shell-bodies-should-not-be-a-lossy-operation/19384>\
**Category:** Modeling Questions\
**Created:** [May 16, 2022, 11:54am UTC](https://discourse.shapr3d.com/t/unioning-subtracting-slicing-shell-bodies-should-not-be-a-lossy-operation/19384 "2022-05-16T11:54:46Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![benaston](https://avatars.discourse-cdn.com/v4/letter/b/bcef8e/32.png) [@benaston](https://discourse.shapr3d.com/u/benaston)\
**Post date:** [May 16, 2022, 11:54am UTC](https://discourse.shapr3d.com/t/unioning-subtracting-slicing-shell-bodies-should-not-be-a-lossy-operation/19384/1 "2022-05-16T11:54:46Z")

</div>

Some outcomes (eg. a chamfer/fillet) need the user to first union (or subtract/slice/shell etc.) two bodies.

However, once the two bodies are unioned, then you lose some modelling flexibility and the compositional-history of the overall part.

Performing a union should optionally be a virtual or lossless operation, with the original sub-bodies retained in some way.

---

<div class="post-metadata">

**Author:** ![Laci\_K](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/laci_k/32/8196_2.png) [@Laci\_K](https://discourse.shapr3d.com/u/Laci_K)\
**Post date:** [May 16, 2022, 12:25pm UTC](https://discourse.shapr3d.com/t/unioning-subtracting-slicing-shell-bodies-should-not-be-a-lossy-operation/19384/2 "2022-05-16T12:25:18Z")

</div>

Hi,

You can select if you want to keep the original bodies or not using the Union tool.

![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/0/031b78ad103994e97a4c9c41a5273e8ccb5512c1.png)