# Polysurface offset

**URL:** <https://discourse.mcneel.com/t/polysurface-offset/200525>\
**Category:** Grasshopper\
**Tags:** windows\
**Created:** [February 28, 2025, 2:11pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525 "2025-02-28T14:11:32Z")\
**Posts on this page:** 20\
**Page:** 1

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**Author:** ![Piet1](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/piet1/32/651191_2.png) [@Piet1](https://discourse.mcneel.com/u/Piet1)\
**Post date:** [February 28, 2025, 2:11pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/1 "2025-02-28T14:11:32Z")

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Hello!!  
is there any fast way to make an offset of the following surface or thickening somehow avoiding to tranform it to mesh ? I’m looking for an inner offset of the whole surface of 2-3 mm.  
Thank you in advance, any suggestions would be really helpful!  
I attach the brep component.  
[Brep offset test.gh](https://discourse.mcneel.com/uploads/short-url/mVKacx1smsOANfaBdj0mISf88EU.gh) (540.2 KB)

 ![Screenshot 2025-02-28 150721](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/6/e/2/6e2611dac04db60e1a0d2471477f61fb7465579b.jpeg)  
 ![Screenshot 2025-02-28 150728](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/c/e/0/ce04516ff5f384ccf154a5782de543519d43ec18.png)

Pit

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**Author:** ![leopoldomonzani](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/leopoldomonzani/32/637191_2.png) [@leopoldomonzani](https://discourse.mcneel.com/u/leopoldomonzani)\
**Post date:** [February 28, 2025, 2:24pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/2 "2025-02-28T14:24:55Z")

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![img1](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/0/5/1/051a4f6880e636847b89d9428de6ae31c0781ea5.jpeg)

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<div class="post-metadata">

**Author:** ![Piet1](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/piet1/32/651191_2.png) [@Piet1](https://discourse.mcneel.com/u/Piet1)\
**Post date:** [February 28, 2025, 2:59pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/3 "2025-02-28T14:59:06Z")

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Hi @leopoldomonzani thanks for the shot but apparently the component gives no result for this brep…

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**Author:** ![martinsiegrist](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/martinsiegrist/32/772775_2.png) [@martinsiegrist](https://discourse.mcneel.com/u/martinsiegrist)\
**Post date:** [February 28, 2025, 2:59pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/4 "2025-02-28T14:59:38Z")

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I tried to offset your polysurface with a script but it failed to produce a good result. What is your goal? 3D print?

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**Author:** ![Piet1](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/piet1/32/651191_2.png) [@Piet1](https://discourse.mcneel.com/u/Piet1)\
**Post date:** [February 28, 2025, 3:08pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/5 "2025-02-28T15:08:52Z")

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Hi @martinsiegrist thank you for replying.  
The goal is coring the part in order to make a part for injection moulding purpose. That’s the reason for offsetting the surface controlling the thickness value.  
Any experience in that?

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**Author:** ![martinsiegrist](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/martinsiegrist/32/772775_2.png) [@martinsiegrist](https://discourse.mcneel.com/u/martinsiegrist)\
**Post date:** [February 28, 2025, 3:12pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/6 "2025-02-28T15:12:13Z")

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I have no experience with injection molding.

Not sure how you created the object… I’d try to start with the main object and add thickness to it before subtracting the holes. Then create each hole with thickness and subtract and union everything.

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**Author:** ![Volker\_Rakow](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/volker_rakow/32/770451_2.png) [@Volker\_Rakow](https://discourse.mcneel.com/u/Volker_Rakow)\
**Post date:** [February 28, 2025, 3:18pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/7 "2025-02-28T15:18:30Z")

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I was about to ask whether you have the original surface before the diamond holes were added.

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**Author:** ![Piet1](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/piet1/32/651191_2.png) [@Piet1](https://discourse.mcneel.com/u/Piet1)\
**Post date:** [February 28, 2025, 3:24pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/8 "2025-02-28T15:24:26Z")

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Created into grasshopper from scratch resulting from a portion of an existing surface extracted.  
This surface has to be integrated in an existing part but within a non native software.  
So you think it would be better working with negative pieces …

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**Author:** ![ftzuk](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/ftzuk/32/689170_2.png) [@ftzuk](https://discourse.mcneel.com/u/ftzuk)\
**Post date:** [February 28, 2025, 3:25pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/9 "2025-02-28T15:25:57Z")

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How accurate does this need to be? You can try rebuild that surface in rhino without the cuts = surface A. Offset surface A = surface B. Intersect hex geometry with surface A and B. Trim those surfaces. Extract hex detail surfs and join with A and B.

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**Author:** ![Piet1](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/piet1/32/651191_2.png) [@Piet1](https://discourse.mcneel.com/u/Piet1)\
**Post date:** [February 28, 2025, 3:32pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/10 "2025-02-28T15:32:10Z")

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Well, accurate enough to get all the details from it. I tried to do something like this but wasn’t that happy with the final result. Now I’m tryng to redo it within gh scaling the hex to get negatives for the srf B…

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<div class="post-metadata">

**Author:** ![Piet1](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/piet1/32/651191_2.png) [@Piet1](https://discourse.mcneel.com/u/Piet1)\
**Post date:** [February 28, 2025, 3:32pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/11 "2025-02-28T15:32:27Z")

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yes I’ve got that

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<div class="post-metadata">

**Author:** ![Volker\_Rakow](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/volker_rakow/32/770451_2.png) [@Volker\_Rakow](https://discourse.mcneel.com/u/Volker_Rakow)\
**Post date:** [February 28, 2025, 3:33pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/12 "2025-02-28T15:33:12Z")

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Can you please provide it?

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<div class="post-metadata">

**Author:** ![ftzuk](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/ftzuk/32/689170_2.png) [@ftzuk](https://discourse.mcneel.com/u/ftzuk)\
**Post date:** [February 28, 2025, 4:06pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/13 "2025-02-28T16:06:47Z")

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Bake the surface. Delete all the hex parts. Select the single remaining surface → \_UntrimAll. Offset that surface to create your thickness and start trimming. You might need to extend some of the hexes around the edges as they’re very shallow.

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<div class="post-metadata">

**Author:** ![Volker\_Rakow](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/volker_rakow/32/770451_2.png) [@Volker\_Rakow](https://discourse.mcneel.com/u/Volker_Rakow)\
**Post date:** [February 28, 2025, 4:35pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/14 "2025-02-28T16:35:50Z")

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> [@ftzuk](#):
>
> Bake the surface. Delete all the hex parts. Select the single remaining surface → \_UntrimAll.

It is so wierd that the Untrim component can’t do this. But guess what component can?

 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/6/1/9/619a05a6391e7a4bdb685cd4edd77436767de24d.jpeg)

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<div class="post-metadata">

**Author:** ![Piet1](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/piet1/32/651191_2.png) [@Piet1](https://discourse.mcneel.com/u/Piet1)\
**Post date:** [February 28, 2025, 4:40pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/15 "2025-02-28T16:40:24Z")

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[Brep offset test.gh](https://discourse.mcneel.com/uploads/short-url/l2C1ec8ek5oEMgEtPy1Pz2I0UuA.gh) (593.4 KB)

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<div class="post-metadata">

**Author:** ![Volker\_Rakow](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/volker_rakow/32/770451_2.png) [@Volker\_Rakow](https://discourse.mcneel.com/u/Volker_Rakow)\
**Post date:** [February 28, 2025, 5:11pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/16 "2025-02-28T17:11:55Z")

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Wait, so the surfaces of the facetted holes aren’t even planar?

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<div class="post-metadata">

**Author:** ![martinsiegrist](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/martinsiegrist/32/772775_2.png) [@martinsiegrist](https://discourse.mcneel.com/u/martinsiegrist)\
**Post date:** [February 28, 2025, 5:55pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/17 "2025-02-28T17:55:20Z")

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Would you mind changing the topic title to ‘Polysurface offset’?

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<div class="post-metadata">

**Author:** ![Piet1](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/piet1/32/651191_2.png) [@Piet1](https://discourse.mcneel.com/u/Piet1)\
**Post date:** [March 2, 2025, 3:46pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/18 "2025-03-02T15:46:06Z")

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Sure but how can I do that? not seeing any modify icon for the topic…

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<div class="post-metadata">

**Author:** ![martinsiegrist](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/martinsiegrist/32/772775_2.png) [@martinsiegrist](https://discourse.mcneel.com/u/martinsiegrist)\
**Post date:** [March 2, 2025, 4:38pm UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/19 "2025-03-02T16:38:50Z")

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I fixed it for you

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<div class="post-metadata">

**Author:** ![Eric27](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/eric27/32/758562_2.png) [@Eric27](https://discourse.mcneel.com/u/Eric27)\
**Post date:** [March 3, 2025, 4:06am UTC](https://discourse.mcneel.com/t/polysurface-offset/200525/20 "2025-03-03T04:06:17Z")

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Here a most efficient solution to offset any polysurface. I join the grasshopper plugin for all to take advantage on it (I just noticed the size does not allow me to upload it, however, I have joined the link.

 ![offset polysurface](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/6/d/0/6d0f75d9812aebca1535aa8bcc2b64f6af349038.jpeg)  
[Brep offset test.gh](https://discourse.mcneel.com/uploads/short-url/ze2MQTFW5GvCFwYHfhsHXwi3XKd.gh) (552.7 KB)  
) . [https://www.radirhino.com/#/plug/6](https://www.radirhino.com/#/plug/6)

[Next page](https://discourse.mcneel.com/t/polysurface-offset/200525.md?page=2)