# Subsurface subdivision problem

**URL:** <https://discourse.mcneel.com/t/subsurface-subdivision-problem/77889>\
**Category:** Grasshopper\
**Created:** [January 26, 2019, 3:22am UTC](https://discourse.mcneel.com/t/subsurface-subdivision-problem/77889 "2019-01-26T03:22:41Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![HS\_Kim](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/hs_kim/32/473975_2.png) [@HS\_Kim](https://discourse.mcneel.com/u/HS_Kim)\
**Post date:** [January 26, 2019, 5:38am UTC](https://discourse.mcneel.com/t/subsurface-subdivision-problem/77889/2 "2019-01-26T05:38:36Z")

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This is one of the most recurrent question regarding subdivision with trimmed or untrimmed surface.  
See the link bellow to understand the underlying theory.  
And I can show you one workaround way on this using Copy Trim and Surface Morph.

[http://docs.mcneel.com/rhino/5/help/en-us/seealso/sak\_splittrim.htm](http://docs.mcneel.com/rhino/5/help/en-us/seealso/sak_splittrim.htm)

[http://docs.mcneel.com/rhino/5/help/en-us/index.htm#commands/untrim.htm](http://docs.mcneel.com/rhino/5/help/en-us/index.htm#commands/untrim.htm)

 ![Canvas%20at%2014%3B01%3B24](https://global.discourse-cdn.com/mcneel/original/3X/8/a/8a358e990b182d88713fd7ea54b4619ce733a903.jpeg)  
[SubdivisionTrimmedSurface\_re.gh](https://global.discourse-cdn.com/mcneel/uploads/default/original/3X/7/4/74b86dea082589a2e18aefcbda2a86091fa58881.gh) (33.0 KB)

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