# Help with Flattening a Curved 3D Model into 2D

**URL:** <https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514>\
**Category:** Modeling Questions\
**Created:** [February 13, 2025, 10:17pm UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514 "2025-02-13T22:17:47Z")\
**Posts on this page:** 16\
**Page:** 1

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**Author:** ![MandoMatt](https://avatars.discourse-cdn.com/v4/letter/m/a87d85/32.png) [@MandoMatt](https://discourse.shapr3d.com/u/MandoMatt)\
**Post date:** [February 13, 2025, 10:17pm UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/1 "2025-02-13T22:17:47Z")

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Hello everyone,  
I’m working on a large 🛳 ship model that will primarily be 3D printed. However, for finer details like railings, I plan to use photo etching to achieve a more realistic look.

I’ve encountered an issue when trying to prepare certain curved railings for the photo-etching process. Specifically, I need to **flatten** a curved 3D model into a 2D design so it can be properly etched and later physically curved into shape.

My initial approach was to use the **Project** tool to transfer the railing’s face onto a Sketch, but this only works on a given plane, resulting in a **distorted, “squished” projection** rather than a proper unrolled version that maintains its true dimensions.

**My Questions:**

1. Is there a way in Shapr3D to **unwrap** or **flatten** a curved object into 2D?

2. If not, does anyone have a workaround (either in Shapr3D or another tool) to accurately extract a **true unwrapped** version of the railing?

I’ve attached a visual of the curved railing for reference:

 ![Curved Railings](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/a/b/ab6a8a8d34f5bed2086d743188895d71dfffb5a3.jpeg)

Based on similar threads, this doesn’t seem to be a feature in Shapr. What third-party solutions should I explore? Any advice or workflow suggestions would be greatly appreciated! Thanks in advance for your help!

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**Author:** ![arroniow](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/arroniow/32/30268_2.png) [@arroniow](https://discourse.shapr3d.com/u/arroniow)\
**Post date:** [February 13, 2025, 10:31pm UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/2 "2025-02-13T22:31:55Z")

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Depending on how you Modelled the railings.  
Shapr can give you the measurement of the length of the railing.  
For any Spline or combination of lines selected, shapr will add the lengths together and display the total length.  
This is true for edges of bodies too.  
This is a good starting point, which would allow you to easily draw it as a flat.  
Like you say there is no unwrap/flatten tool that will do that.

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**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 14, 2025, 1:17am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/3 "2025-02-14T01:17:31Z")

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In this post I recommend an alternative software near the end, this is asked pretty frequently, flattening tool would be nice within shaper.

Some shapes like this I want to 3d print flat with curvature so I can bend it and glue the miniature rail on to the ship.

I’m actually curious how you created this railing. It starts at 90degree and centers to like 45degree want to try to figure that out.

> [@How to make unwrapped drawing of a tube](https://discourse.shapr3d.com/t/how-to-make-unwrapped-drawing-of-a-tube/33318):
>
> Hi, I have a model of a tube, with specific holes and assets on it, and I’d like to get a drawing of an unwrapped tube, i.e. - a flat view of the tube’s outer surface, so I can print it with 1:1 scale and wrap it around the real tube and make whatever I want. The same goes with other bended bodies - their drawing always appears as a projection, not as an unwrapped surface of the whole piece. In general - it would be nice to have a drawing of a face. How can I achieve this result now? Thank yo…

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**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 14, 2025, 7:40am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/4 "2025-02-14T07:40:32Z")

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I made models of stadiums in the past, this kinda reminded me of ways to improve for next time. I had lot of issues with stadium posts that the shades sit on looking back I should have printed flat connected by rails. If it’s on rails posts could have been rolled out and glued on.

> [@Stadium](https://discourse.shapr3d.com/t/stadium/35325):
>

I modeled it this way because, I only need the face for testing.

 ![Pasted Graphic 6](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/9/2/92ea52c9aa123a0634cebd3f04906935041779e9.jpeg)

Got the face flattened with Onshape, but it’s expensive.

 ![Pasted Graphic 7](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/b/f/bf7c10188a07e446be49e4691e34eea771291887.jpeg)

The Unfold app did pretty good job as well but there are small gaps, those can be fixed with any vector app. I like this app because it’s more general purpose and cheap.

 ![Pasted Graphic 8](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/3/0/3003d80f6a818f5e56eb0ce77a217c8d708bd636.jpeg)

Next step is to 3dprint and check if alignment check out on a base.

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<div class="post-metadata">

**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 14, 2025, 7:55am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/5 "2025-02-14T07:55:05Z")

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![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/8/0/80d4e9006a46288cdef76f7af9b0d392547e1a88.png)

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<div class="post-metadata">

**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 15, 2025, 7:24am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/6 "2025-02-15T07:24:40Z")

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Came out as anticipated.

 ![IMG_20250214_231512](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/3/d/3dbb52f225c78ec2eff3435bedd14866ba9b79a4.jpeg)

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<div class="post-metadata">

**Author:** ![arroniow](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/arroniow/32/30268_2.png) [@arroniow](https://discourse.shapr3d.com/u/arroniow)\
**Post date:** [February 15, 2025, 2:16pm UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/7 "2025-02-15T14:16:14Z")

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That worked out well.  
The question is “Has the originator of the help request been back to have a look?”

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<div class="post-metadata">

**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 15, 2025, 3:50pm UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/8 "2025-02-15T15:50:26Z")

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More than that this topic is asked at least few times a month and shows the real need for flattening tool within Shapr. Lot of people could benefit from it, from model makers to, home craft makers, origami makers. One person needed a cylinder flattened so he could print out in paper all the screw marks. Hopefully Shapr also see this and give use flatten feature after the Variable Parametrics. Shapr like to highlight Shapr is in between APP for Designers and Engineers. But I kinda think lot of users are also hobbyist with this app starting from iPad who’s audience are more design focused than engineering.

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<div class="post-metadata">

**Author:** ![MandoMatt](https://avatars.discourse-cdn.com/v4/letter/m/a87d85/32.png) [@MandoMatt](https://discourse.shapr3d.com/u/MandoMatt)\
**Post date:** [February 16, 2025, 11:07am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/9 "2025-02-16T11:07:25Z")

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@SCALEMODEL THANK YOU so much for the thorough reply and app recommendation.

I’m still playing with _Unfolder_, but not having much luck just yet. I need to use it a bit more and perhaps try different variations of my model. Just the beginning though 🙂

Again, THANK YOU!

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<div class="post-metadata">

**Author:** ![MandoMatt](https://avatars.discourse-cdn.com/v4/letter/m/a87d85/32.png) [@MandoMatt](https://discourse.shapr3d.com/u/MandoMatt)\
**Post date:** [February 16, 2025, 11:10am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/10 "2025-02-16T11:10:19Z")

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> [@SCALEMODEL](#):
>
> More than that this topic is asked at least few times a month and shows the real need for flattening tool within Shapr. Lot of people could benefit from it, from model makers to, home craft makers, origami makers

@Istvan 👆I couldn’t agree more.

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**Author:** ![arroniow](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/arroniow/32/30268_2.png) [@arroniow](https://discourse.shapr3d.com/u/arroniow)\
**Post date:** [February 22, 2025, 11:42am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/12 "2025-02-22T11:42:26Z")

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It is a nice model, with some great detail 👏

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**Author:** ![jean-philippe2](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/jean-philippe2/32/27353_2.png) [@jean-philippe2](https://discourse.shapr3d.com/u/jean-philippe2)\
**Post date:** [February 23, 2025, 4:41am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/13 "2025-02-23T04:41:21Z")

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> [@SCALEMODEL](#):
>
> Got the face flattened with Onshape, but it’s expensive.

Hi,  
You can get Onshape Free version and it’s perfect. Wrap, unwrap and other.

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<div class="post-metadata">

**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 23, 2025, 5:09am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/14 "2025-02-23T05:09:54Z")

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Yes its free for hobbyist and for non commercial work so it depends.

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<div class="post-metadata">

**Author:** ![jean-philippe2](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/jean-philippe2/32/27353_2.png) [@jean-philippe2](https://discourse.shapr3d.com/u/jean-philippe2)\
**Post date:** [February 23, 2025, 5:40am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/15 "2025-02-23T05:40:18Z")

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OK ! you are right.  
But you can just doing the unwrap step in Onshape and export it in Parasolid to import in Shapr3d

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<div class="post-metadata">

**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 23, 2025, 5:58am UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/16 "2025-02-23T05:58:06Z")

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Ya actually above I showed 2 examples one from Onshape, the flat black one.

One thing the Unfolder does that onshape doesn’t is it automatically accounts for the impossible curve by braking the connection to create relief stress cut. Solidworks is lot better at doing relief cuts and has more options, like resolution levels.

3d printed piece was from Onshape.

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<div class="post-metadata">

**Author:** ![jean-philippe2](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/jean-philippe2/32/27353_2.png) [@jean-philippe2](https://discourse.shapr3d.com/u/jean-philippe2)\
**Post date:** [February 23, 2025, 3:59pm UTC](https://discourse.shapr3d.com/t/help-with-flattening-a-curved-3d-model-into-2d/36514/17 "2025-02-23T15:59:16Z")

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perhaps i don’t understand what you want.  
Here, in MoI3d.  
Use UnwrapCone script and Flow tool.  
See screenshot.

 ![Capture d’écran 2025-02-23 à 16.46.45](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/4/1/4107ecbd8c85f736f2c9f54589b42fab519662fc.jpeg)