You might want to download a model to 3D print it. You’ll find files on Sketchfab that are ready for 3D printing, but if they’re not, you may have to fix them up first. After all, your models will have to be physically ‘possible’ if you want to print them (and yeah, visualization artists can cheat, but 3D printing designers can’t!).
Quick 3D printable check-list (all of these depend on the printer that you’re going to use, so check with the owner):
- What kind of file format does your printer require? Most printers will accept STL files, although commercial services can work with a wider range of file types (like for full color printing, see below). Most 3D applications can export to STL so it’s easy to convert a model that you downloaded from Sketchfab.
- Is your model ‘watertight’? 3D printers get confused if there’s a ‘leak’ in your model – essentially this would reduce the model to a two-dimensional shell. So take care to close your model! Of course you can still have models with holes in them, like a donut, but make sure that the surface is continuous and closed.
- Related to the concept of watertight is ‘manifold’. This is a mathematical term describing object surfaces. Basically, it says that the surface can exist in reality – the main requirement being that each edge of your model neighbours to exactly 2 faces. Most 3D apps have support for testing manifoldness. If yours doesn’t, try the free Meshlab software. For more information on this topic, see this excellent tutorial on Shapeways.
- Does your model conform to your printer’s minimum wall thickness (the thinnest part it can print), and will it fit? Each printer has it’s own minimum and maximum model sizes, be sure to check them!
- Overhang – this is a bit more technical, but especially FDM printers (like Ultimakers or Makerbots) have a limit to the ‘angle’ of some of the faces. A large overhang will require adding support material. Again, check with your printer or its owner if he can add support.
- Full color support. Most printers these days print in one material. Only a few can handle full color like the ZCorp or Visijet printers. For ‘monochrome’ printers, an STL file is fine. For full color, you’ll usually have to provide a VRML file with the required UV maps.
- Polygon threshold, the maximum number of polygon the printer can handle. Keep the printer resolution in mind when deciding on the polygon count. Details that are below the resolution won’t get printed anyway, so don’t bother sending them to your printer. A good rule of thumb is not to go over 1 million triangles. You can use mesh decimation software to remove unneeded details while still preserving your model’s shape. Again, MeshLab is your friend if your own 3D software doesn’t already offer this. Here’s a great video tutorial talking you through it.
- Price. 3D printed models can get expensive fast! Most printing services base their price on the printed volume. As such, increasing your model’s size by a factor of two will result in an 8x increase in price (remember, volume is the cube of the size). The good news is that you often only need a small size adjustment to make your print match your budget.
Now that you are familiar with the basic concepts linked to 3D printing, you might want to dive in a little more on specific topics. Here are some useful links and tutorials to explore some concepts and techniques more in depth:
- Photoshop allows you to prepare files for 3D printing, here’s a guide.
- A lengthy guide on 3D printing for beginners by 3DPrinterPlans.
- How to guide to 3D model character models for 3D printing this Shapeways tutorial is a good resource to start with.
- How to adjust your animation/characters for 3d printing, a video tutorial.
- If you want to print in color, check out the FCS material guideline here, and here’s the official checklist to go through before you’re about to 3D print with Shapeways.
- Preparing Blender files for 3D printing, a video tutorial by CG Cookie.
- 3D printing on the Form 1 + Formlabs, a tutorial on CG Cookie.
- Free software for file conversion: http://meshlab.sourceforge.net/
- Free tool to test if your model is 3D printable: http://www.willit3dprint.com/
- Autodesk MeshMixer is a great tool for creating mashups of existing models. And it’s free!
That’s it you’re ready to enter the wonderful world of 3D printing, have fun along the way and don’t forget to share photos of your prints with us! You can send them to email@example.com, or simply tweet them with the hashtag #Sketchfabulous
— Jerome Maurey (@jeromemaurey)
October 31, 2014