<p>You've not offered the source of the model, nor the software from which it was created, but I suspect that you'll find the "invisible" faces have reversed normals. This is a characteristic of modeling software that believes the outside is the inside and vice versa. If you are comfortable with using another program, you can check/confirm those problematic sections.</p>

<p>I'm fond of Meshmixer, a multi-platform 3D modeling and editing program. It will display reversed normals with a bit of zebra striping. One can use the Select tool, highlight those faces and use the Select Edit, reverse normals menu entry to repair the problem.</p>

<p>Some slicers will automatically repair this type of problem. For a different approach, download and import your model into Slic3r, which will indicate that it has corrected xx errors.</p>

CC BY-SA 4.0
2019-04-16T01:23:53.547Z
The model was created using Sketchup
user15166
CC BY-SA 4.0
2019-04-16T02:21:33.353Z
@user15166 sketchup shades faces differently based on their orientation. You can right-click the model and select "orient faces" to see if a square or two will flip, or you can reverse specific faces directly too.
kolosy
CC BY-SA 4.0
2019-04-16T09:04:37.357Z
In Sketchup view as x-ray to see and delete internal hidden objects.  On faces delete internal lines where you merged objects to make one face.  Leave only the outline of the faces.
Perry Webb
CC BY-SA 4.0
2019-04-16T00:35:38.533Z
2019-04-16T00:35:38.533Z
fred_dot_u
<p>I have a 3D model that is essentially a mostly outer cylinder but with some geometries in the inner wall. However, it seems that MakerBot print software is having trouble interpreting places when the outer wall is just a thin face (with no thickness) and makes the model seem transparent there when looking from the inside, even though it looks solid from the outside. I think for this reason, the model is completely filling in the cylinder in those places, which is what I am trying to fix. </p>

<p>Any suggestions would be appreciated.</p>

<p><a href="https://i.sstatic.net/ck4eF.png" rel="noreferrer" title="Outside view"><img src="https://i.sstatic.net/ck4eF.png" alt="Outside view" title="Outside view"></a></p>

<p><a href="https://i.sstatic.net/RGBcM.png" rel="noreferrer" title="Inside view"><img src="https://i.sstatic.net/RGBcM.png" alt="Inside view" title="Inside view"></a></p>

<makerbot>
How to fix transparent outer face?
user15166
# How to fix transparent outer face?

(Asked by: username_0 on 2019-04-16)

I have a 3D model that is essentially a mostly outer cylinder but with some geometries in the inner wall. However, it seems that MakerBot print software is having trouble interpreting places when the outer wall is just a thin face (with no thickness) and makes the model seem transparent there when looking from the inside, even though it looks solid from the outside. I think for this reason, the model is completely filling in the cylinder in those places, which is what I am trying to fix.

Any suggestions would be appreciated.

[![Outside view](https://i.sstatic.net/ck4eF.png "Outside view")](https://i.sstatic.net/ck4eF.png "Outside view")

[![Inside view](https://i.sstatic.net/RGBcM.png "Inside view")](https://i.sstatic.net/RGBcM.png "Inside view")

**Tags:** makerbot


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## 1 answers

### Answer by username_1 on 2019-04-16. Score: 4

You've not offered the source of the model, nor the software from which it was created, but I suspect that you'll find the "invisible" faces have reversed normals. This is a characteristic of modeling software that believes the outside is the inside and vice versa. If you are comfortable with using another program, you can check/confirm those problematic sections.

I'm fond of Meshmixer, a multi-platform 3D modeling and editing program. It will display reversed normals with a bit of zebra striping. One can use the Select tool, highlight those faces and use the Select Edit, reverse normals menu entry to repair the problem.

Some slicers will automatically repair this type of problem. For a different approach, download and import your model into Slic3r, which will indicate that it has corrected xx errors.

> **Comments:**
> **username_0**: The model was created using Sketchup  
> **username_2**: @username_0 sketchup shades faces differently based on their orientation. You can right-click the model and select "orient faces" to see if a square or two will flip, or you can reverse specific faces directly too.  
> **username_3**: In Sketchup view as x-ray to see and delete internal hidden objects.  On faces delete internal lines where you merged objects to make one face.  Leave only the outline of the faces.  

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