How to edit Thingiverse STL files
Posted by shadowjig
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Re: How to edit Thingiverse STL files August 27, 2013 05:39AM |
Lets say it this way:
STL is a one way ticket!
Deviating geometries from a mathematically defined model (Step; 3DM etc) to e.g. STL or VRML or one of the more illustrative file formats like OBJ oder 3ds always leads to a discretization of information ( in case of the illustrative files the renderer/ shader afterwards improves the facette look to back into a smooth appearance - the discretization is made to save calculation time and the improvement is just for the visualization not for the geometry!
A SPLINE or NURBS mesh always relates to functions similar to polynoms so you can calculate for each point on such an object an individual solution.
STL and the others consist of triangles or squares which have straight / flat facettes - so any additional information is lost in conversion and can not be restored! For manufacturing, maximum conversion quality is reached as the longest edge on the largest triangle is defined equal or smaller than the possible step resolution of the machine axis!! This would mean huge files ( larger than the mathematical files which were the origin) and so usually the resolution is chosen to be much lower!!
This is a typical OBJ or VRML Mesh
This is done from a typical mathematical model ( you still can see the isobate lines on the surfaces)
Hj
Edited 2 time(s). Last edit at 08/27/2013 05:44AM by Optimist.
STL is a one way ticket!
Deviating geometries from a mathematically defined model (Step; 3DM etc) to e.g. STL or VRML or one of the more illustrative file formats like OBJ oder 3ds always leads to a discretization of information ( in case of the illustrative files the renderer/ shader afterwards improves the facette look to back into a smooth appearance - the discretization is made to save calculation time and the improvement is just for the visualization not for the geometry!
A SPLINE or NURBS mesh always relates to functions similar to polynoms so you can calculate for each point on such an object an individual solution.
STL and the others consist of triangles or squares which have straight / flat facettes - so any additional information is lost in conversion and can not be restored! For manufacturing, maximum conversion quality is reached as the longest edge on the largest triangle is defined equal or smaller than the possible step resolution of the machine axis!! This would mean huge files ( larger than the mathematical files which were the origin) and so usually the resolution is chosen to be much lower!!
This is a typical OBJ or VRML Mesh
This is done from a typical mathematical model ( you still can see the isobate lines on the surfaces)
Hj
Edited 2 time(s). Last edit at 08/27/2013 05:44AM by Optimist.
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Re: How to edit Thingiverse STL files August 27, 2013 06:40PM |
Quote
Optimist
STL is a one way ticket!
That's one nice way to put it.
I'm not as nice: I call STL "garbage out". Because to experienced CAD users, that's what it is.
STL is unsuitable for most large-scale manufacturing processes (injection molding) and even some small-scale ones (CNC machining).
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Re: How to edit Thingiverse STL files April 24, 2017 11:01PM |
What's FutureWorks?
I haven't used SolidWorks in years. For personal projects I prefer to use open source software on an open source operating system. As it happens, FreeCAD (also available on proprietary operating systems ) can convert STL files to solid.
[www.freecadweb.org]
Once done, you can export to STEP then import into SolidWorks.
Just remember that an STL file is a polygon mesh, it does not have smooth surfaces. For example a cylindrical surface is actually made of multiple facets. When converting to solid, it will not smooth the surfaces. For that you have no choice but to rebuild the model.
Edited 1 time(s). Last edit at 04/24/2017 11:03PM by NormandC.
I haven't used SolidWorks in years. For personal projects I prefer to use open source software on an open source operating system. As it happens, FreeCAD (also available on proprietary operating systems
) can convert STL files to solid.[www.freecadweb.org]
Once done, you can export to STEP then import into SolidWorks.
Just remember that an STL file is a polygon mesh, it does not have smooth surfaces. For example a cylindrical surface is actually made of multiple facets. When converting to solid, it will not smooth the surfaces. For that you have no choice but to rebuild the model.
Edited 1 time(s). Last edit at 04/24/2017 11:03PM by NormandC.
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Re: How to edit Thingiverse STL files March 03, 2020 06:03PM |
Quote
Lepes
Edit: OMG, I didn't see the second page of this thread facepalm!
To be honest, Blender is not the best software if you know nothing about it, although I encourage to learn it because:
- It's Open Source
- It's free
- It can do whatever you want: Split, modify, create, measure it, animate things and create a video, etc.
- It has a great and big community (infinite information, lots of free plugins)
- There are infinite tutorials on Youtube, for any user level.
Keep in mind that there are 2 differents kind of software to create/modify STL:
- CAD software: FreeCad, SolidWork
- organic modelling: Blender, Rhinoceros, etc..
If you don't like blender, just search on Youtube. I really don't know your level on those softwares, so maybe the one I suggest is not for you.
Some Examples:
[www.youtube.com]
[www.youtube.com]
Blender can do cool stuff. Unfortunately, you need to be an expert before you can be a beginner!
There are no manuals to speak of, people's advice assumes you already know how to drive it, and the user interface is horrific. You know, Open Source.
I have done some useful stuff with it, but heck, I tried for an hour just to change the UI colors to something other than gray text on black background...And failed.
Folks need to stop adding stuff to it and start making it usable (IMO).
DLC
Edited 1 time(s). Last edit at 03/03/2020 06:04PM by dlc60.
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Re: How to edit Thingiverse STL files March 04, 2020 05:46AM |
Quote
dlc60
Blender can do cool stuff. Unfortunately, you need to be an expert before you can be a beginner!
There are no manuals to speak of, people's advice assumes you already know how to drive it, and the user interface is horrific. You know, Open Source.
I have done some useful stuff with it, but heck, I tried for an hour just to change the UI colors to something other than gray text on black background...And failed.
Folks need to stop adding stuff to it and start making it usable (IMO).
DLC
If you think so, you didn't find the correct Youtuber for you. There are plenty of videos and courses "learning Blender from scratch".
Videos always say press some Hotkey but nobody tells you that those hotkeys are on the menu bar, so the first time He uses that hotkey, He should teachs you where it is. You can forget that hotkey, but you will not forget where is the menu option.
I understand what you said and I agree with you on some aspects. Interface has been changed 3 times since I started with it. It is not a problem for me, my workflow is exactly the same in all versions.
Do you know that each text box where you type numbers is a calculator in blender? You can introduce expression like "34.86*2" (to duplicate size) or "sin(45)" (if you like)
Do you know you can turn around selection? I can not move my camera around an object if I don't use that preference. A few people use that tool, select a vertice and then orbit with middle mouse button around it, I love it!.
Yes, you need to master blender and then, you start again as a noob discovering something that is 15 years implemented and nobody told you
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