<p>An STL file is a surface model file. From Wikipedia you can <a href="https://en.wikipedia.org/wiki/STL_(file_format)" rel="noreferrer">read</a> that:</p>

<blockquote>
  <p>STL files describe only the surface geometry of a three-dimensional
  object without any representation of color, texture or other common
  CAD model attributes.</p>
</blockquote>

<p>This implies that there is no such thing as a wall thickness, as such you will not be able to determine the wall thickness (it is infinitesimally small). You might be interested in part thickness at a certain position; part thickness and wall thickness for 3D printing are determined when the STL model is sliced into sliced for creating 3D printer code.</p>

CC BY-SA 4.0
2018-12-10T14:05:06.543Z
yes and no: STL could contain a relative wall thickness... if the wall has inside and outside wall modeled....
Trish
CC BY-SA 4.0
2018-12-11T16:26:38.830Z
One thing is wall thickness as part of the model (model wall) and other the wall thickness as the (shield) to be printed, this part is according how many lines you need on your print that coul be from 1 line to 5 or more is your models supports those number of lines; if not the slicer just will apply that number of lines that fits inside de model walls, for example just one line. If the CAD has a measing rule and the STL is showing (of course) the walls these can be measured; obviuosly the shield cant be measured due is part of the printing process.
Fernando Baltazar
CC BY-SA 4.0
2018-12-12T15:09:27.313Z
@FernandoBaltazar STL does not contain any information about the number of shells or infill. it is just the outer shells. if shells are nested into each other, they can generate internal walls.
Trish
CC BY-SA 4.0
2018-12-12T17:52:00.837Z
@Trish Right, I'm not telling nothing about STL information; I'm talking about Object and its dimension because is a figure so has dimensions and that can be resized. Also I pointed as obvious the shields can't be measured due that parameters are part of printing process, this mean that are variants depending on each user and each machine.
Fernando Baltazar
CC BY-SA 4.0
2018-12-10T13:04:47.793Z
2018-12-10T13:04:47.793Z
0scar
<p>I am using a node app that displays stls online &amp; analyzes them. Is it possible to determine the minimum wall thickness of the stl just like 3D Hubs print analyzer does?</p>

CC BY-SA 4.0
2018-12-10T13:00:20.517Z
Absolute Thickness? Relative thickness? In extrusions?
Trish
CC BY-SA 4.0
2018-12-10T13:50:08.337Z
Do you mean you're *writing* the node app? If you're just *using* the app, it doesn't matter if three.js can do it, it only matters whether the app can do it.
Dan Hulme
<print-quality><stl>
Is it possible to use Three.js to determine the wall thickness of an STL file?
LX V
# Is it possible to use Three.js to determine the wall thickness of an STL file?

(Asked by: username_0 on 2018-12-10)

I am using a node app that displays stls online & analyzes them. Is it possible to determine the minimum wall thickness of the stl just like 3D Hubs print analyzer does?

**Tags:** print-quality, stl
> **Comments:**
> **username_1**: Absolute Thickness? Relative thickness? In extrusions?  
> **username_2**: Do you mean you're *writing* the node app? If you're just *using* the app, it doesn't matter if three.js can do it, it only matters whether the app can do it.  

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## 1 answers

### Answer by username_3 on 2018-12-10. Score: 5

An STL file is a surface model file. From Wikipedia you can [read](https://en.wikipedia.org/wiki/STL_(file_format)) that:

> STL files describe only the surface geometry of a three-dimensional
> object without any representation of color, texture or other common
> CAD model attributes.

This implies that there is no such thing as a wall thickness, as such you will not be able to determine the wall thickness (it is infinitesimally small). You might be interested in part thickness at a certain position; part thickness and wall thickness for 3D printing are determined when the STL model is sliced into sliced for creating 3D printer code.

> **Comments:**
> **username_1**: yes and no: STL could contain a relative wall thickness... if the wall has inside and outside wall modeled....  
> **username_4**: One thing is wall thickness as part of the model (model wall) and other the wall thickness as the (shield) to be printed, this part is according how many lines you need on your print that coul be from 1 line to 5 or more is your models supports those number of lines; if not the slicer just will apply that number of lines that fits inside de model walls, for example just one line. If the CAD has a measing rule and the STL is showing (of course) the walls these can be measured; obviuosly the shield cant be measured due is part of the printing process.  
> **username_1**: @FernandoBaltazar STL does not contain any information about the number of shells or infill. it is just the outer shells. if shells are nested into each other, they can generate internal walls.  
> **username_4**: @Trish Right, I'm not telling nothing about STL information; I'm talking about Object and its dimension because is a figure so has dimensions and that can be resized. Also I pointed as obvious the shields can't be measured due that parameters are part of printing process, this mean that are variants depending on each user and each machine.  

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