<p>Opening the file in Meshmixer and then using the <a href="https://help.autodesk.com/view/MSHMXR/2019/ENU/?guid=GUID-83BC663B-FA1C-46D3-8C2F-82EB6892DFC3" rel="nofollow noreferrer"><code>Analysis &gt; Inspector</code> tool</a> creates a colorful note, showing LOTS of errors in this model: </p>

<p><a href="https://i.sstatic.net/YSDFM.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/YSDFM.png" alt="Default settings Analysis look at the model"></a></p>

<p>A lot of the magenta errors, a few blue ones. Magenta means "this detail has a small surface area, we'd delete it". Blue means "Here's a hole in the surface, we'd stitch it". The black surface is pink as are some details we want to preserve, so let's change what is considered small: Pushing the <code>Small Thresh</code> to the left (<code>0 mm</code>) removes all the pink and leaves only blue and a few red spots. Like the windscreens, they are red now.</p>

<p><a href="https://i.sstatic.net/px5Nm.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/px5Nm.png" alt="Analysis look with 0mm small threshold"></a></p>

<p>Red means "here are some non-manifold regions, we'd create a surface to fix this". After clicking on <code>Auto Repair All</code> it looks like this, having fixed a lot of these pins but definitely not all of them, as the MeshMixer engine runs against its limits trying to fix this sea urchin. But it is much better.</p>

<p><a href="https://i.sstatic.net/VXr4H.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/VXr4H.png" alt="After Auto Repair"></a></p>

<p>This is still a messed up model containing 416 non-closed shells (only 401 after repair), but now there <em>is</em> a surface at the windows, yet not a very good one. Another example of this model's many errors: the port intake consists of 17 times the same thing copy-pasted next to itself - and it has no lower surface, making this just an open surface and not a solid object</p>

<p><a href="https://i.sstatic.net/P8L6t.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/P8L6t.png" alt="Port intake"></a></p>

<p>In my honest opinion, it would be more effective to fix this with Blender on a vertex level and stitching all the orphaned surfaces together. This model was most likely made for a video game and fixing up game models for 3D printing is at times pretty much recreating it from scratch.</p>

CC BY-SA 4.0
2018-08-24T15:39:59.377Z
2018-08-24T15:50:33.993Z
2018-08-24T15:50:33.993Z
Trish
<p>With the model file available, I was able to use Edit, Generate Face Groups. This allows one to continue with Select, {set small cursor}, select reversed panels, Edit, Flip Normals.</p>

<p>The above steps resolve the cockpit windows, but meshmixer's Analysis, Inspector shows a sea-urchin-presentation of other flaws, including what appears to be zero thickness walls in some locations.</p>

CC BY-SA 3.0
2018-04-26T15:55:02.950Z
I can fix the walls using the make solid feature. I will give this a try and tell you how it goes.
Brendan Smith
CC BY-SA 3.0
2018-04-26T16:49:37.383Z
Sometimes the cursor in select mode won't follow the mouse. Any ideas on how to fix this?
Brendan Smith
CC BY-SA 3.0
2018-04-26T18:23:58.227Z
I've had that happen when the cursor size is excessive for the area being selected or sometimes when it's lag/delay due to the processing involved.
fred_dot_u
CC BY-SA 3.0
2018-04-27T21:28:35.350Z
I'm not sure. I have the brush size set to 1 and I'm running meshmixer on an inspiron 15 7000 gaming, which has no problem running 2 games at one, so I don't think that the processing speed is an issue.
Brendan Smith
CC BY-SA 3.0
2018-04-26T11:32:00.843Z
2018-04-26T11:32:00.843Z
fred_dot_u
<p>I was working on a model today and I need to make the black surface into a normal surface so that the ship's cockpit is solid. I am unable to select the black surface. I tried using the flip normals feature, but I was still unable to select it. Any advice on how to make it into a solid is greatly appreciated. Thanks. :)</p>

<p>Edit: Here's the link to the file
<a href="https://drive.google.com/file/d/1mbTdeeZqhNJx-WlXNqF8mD8QYDSI3Vh_/view?usp=sharing" rel="nofollow noreferrer">https://drive.google.com/file/d/1mbTdeeZqhNJx-WlXNqF8mD8QYDSI3Vh_/view?usp=sharing</a></p>

<p><a href="https://i.sstatic.net/bInCO.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/bInCO.png" alt="The weired surface in meshmixer"></a></p>

CC BY-SA 3.0
2018-04-26T00:47:50.020Z
Would you consider to attach the file to determine more precisely the failure mode? Even if you don't wish to attach the entire file, use plane cut and cut the plane just below the cockpit. This would maintain any IP considerations for your model.
fred_dot_u
CC BY-SA 3.0
2018-04-26T04:21:20.147Z
Just added a google drive link.
Brendan Smith
CC BY-SA 4.0
2018-07-25T13:02:48.270Z
Hi Brendan! Have you found and fixed the problem? If so, has the answer below led you to the solution? Please vote to accept the answer so this question is not bumped up once in a while and can be removed from the unanswered question list. You may even add your own solution and accept that after 48 hours! If you have not been able to address the problem please update your question.
0scar
<3d-models><3d-design><stl>
Black surface in Meshmixer
Brendan Smith
# Black surface in Meshmixer

(Asked by: username_0 on 2018-04-26)

I was working on a model today and I need to make the black surface into a normal surface so that the ship's cockpit is solid. I am unable to select the black surface. I tried using the flip normals feature, but I was still unable to select it. Any advice on how to make it into a solid is greatly appreciated. Thanks. :)

Edit: Here's the link to the file
<https://drive.google.com/file/d/1mbTdeeZqhNJx-WlXNqF8mD8QYDSI3Vh_/view?usp=sharing>

[![The weired surface in meshmixer](https://i.sstatic.net/bInCO.png)](https://i.sstatic.net/bInCO.png)

**Tags:** 3d-models, 3d-design, stl
> **Comments:**
> **username_1**: Would you consider to attach the file to determine more precisely the failure mode? Even if you don't wish to attach the entire file, use plane cut and cut the plane just below the cockpit. This would maintain any IP considerations for your model.  
> **username_0**: Just added a google drive link.  
> **username_2**: Hi Brendan! Have you found and fixed the problem? If so, has the answer below led you to the solution? Please vote to accept the answer so this question is not bumped up once in a while and can be removed from the unanswered question list. You may even add your own solution and accept that after 48 hours! If you have not been able to address the problem please update your question.  

---

## 2 answers

### Answer by username_3 on 2018-08-24. Score: 1

Opening the file in Meshmixer and then using the [`Analysis > Inspector` tool](https://help.autodesk.com/view/MSHMXR/2019/ENU/?guid=GUID-83BC663B-FA1C-46D3-8C2F-82EB6892DFC3) creates a colorful note, showing LOTS of errors in this model:

[![Default settings Analysis look at the model](https://i.sstatic.net/YSDFM.png)](https://i.sstatic.net/YSDFM.png)

A lot of the magenta errors, a few blue ones. Magenta means "this detail has a small surface area, we'd delete it". Blue means "Here's a hole in the surface, we'd stitch it". The black surface is pink as are some details we want to preserve, so let's change what is considered small: Pushing the `Small Thresh` to the left (`0 mm`) removes all the pink and leaves only blue and a few red spots. Like the windscreens, they are red now.

[![Analysis look with 0mm small threshold](https://i.sstatic.net/px5Nm.png)](https://i.sstatic.net/px5Nm.png)

Red means "here are some non-manifold regions, we'd create a surface to fix this". After clicking on `Auto Repair All` it looks like this, having fixed a lot of these pins but definitely not all of them, as the MeshMixer engine runs against its limits trying to fix this sea urchin. But it is much better.

[![After Auto Repair](https://i.sstatic.net/VXr4H.png)](https://i.sstatic.net/VXr4H.png)

This is still a messed up model containing 416 non-closed shells (only 401 after repair), but now there *is* a surface at the windows, yet not a very good one. Another example of this model's many errors: the port intake consists of 17 times the same thing copy-pasted next to itself - and it has no lower surface, making this just an open surface and not a solid object

[![Port intake](https://i.sstatic.net/P8L6t.png)](https://i.sstatic.net/P8L6t.png)

In my honest opinion, it would be more effective to fix this with Blender on a vertex level and stitching all the orphaned surfaces together. This model was most likely made for a video game and fixing up game models for 3D printing is at times pretty much recreating it from scratch.


---

### Answer by username_1 on 2018-04-26. Score: 1

With the model file available, I was able to use Edit, Generate Face Groups. This allows one to continue with Select, {set small cursor}, select reversed panels, Edit, Flip Normals.

The above steps resolve the cockpit windows, but meshmixer's Analysis, Inspector shows a sea-urchin-presentation of other flaws, including what appears to be zero thickness walls in some locations.

> **Comments:**
> **username_0**: I can fix the walls using the make solid feature. I will give this a try and tell you how it goes.  
> **username_0**: Sometimes the cursor in select mode won't follow the mouse. Any ideas on how to fix this?  
> **username_1**: I've had that happen when the cursor size is excessive for the area being selected or sometimes when it's lag/delay due to the processing involved.  
> **username_0**: I'm not sure. I have the brush size set to 1 and I'm running meshmixer on an inspiron 15 7000 gaming, which has no problem running 2 games at one, so I don't think that the processing speed is an issue.  

---

