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3D Printing: Modeling

Starting with an existing model

The easiest way to learn to design models for 3D printing is perhaps to modify an existing model. There are several free or paid models available.

Designing your own model

Once you have mastered the basics of modeling and have become familiar with the software, you can start exploring how to create your own model. You are only limited by your imagination…and the specifications of the machine, material, and printing technique you choose!

 


This head is made up of hundreds of triangles

The STL format

The STL file format (for STereoLithography) has become the norm in 3D printing. Most machines and modeling software support it.

Such files contain, most often in plain text, the list of triangles (facets) that make up the object with their 3D coordinates (X, Y, Z axes). So, to design a cube, you need 12 triangles as demonstrated in the example below:

Click to scroll through the STL format code

solid MYSOLID
  facet normal  0.0   0.0  -1.0    
    outer loop
      vertex    0.0   0.0   0.0    
      vertex    1.0   1.0   0.0    
      vertex    1.0   0.0   0.0    
    endloop
  endfacet
  facet normal  0.0   0.0  -1.0    
    outer loop
      vertex    0.0   0.0   0.0 
      vertex    0.0   1.0   0.0    
      vertex    1.0   1.0   0.0    
    endloop
  endfacet
  facet normal -1.0   0.0   0.0    
    outer loop
      vertex    0.0   0.0   0.0
      vertex    0.0   1.0   1.0
      vertex    0.0   1.0   0.0
    endloop
  endfacet
  facet normal -1.0   0.0   0.0    
    outer loop
      vertex    0.0   0.0   0.0
      vertex    0.0   0.0   1.0
      vertex    0.0   1.0   1.0
    endloop
  endfacet
  facet normal  0.0   1.0   0.0    
    outer loop
      vertex    0.0   1.0   0.0
      vertex    1.0   1.0   1.0
      vertex    1.0   1.0   0.0
    endloop
  endfacet
  facet normal  0.0   1.0   0.0    
    outer loop
      vertex    0.0   1.0   0.0
      vertex    0.0   1.0   1.0
      vertex    1.0   1.0   1.0
    endloop
  endfacet
  facet normal  1.0   0.0   0.0    
    outer loop
      vertex    1.0   0.0   0.0
      vertex    1.0   1.0   0.0
      vertex    1.0   1.0   1.0
    endloop
  endfacet
  facet normal  1.0   0.0   0.0    
    outer loop
      vertex    1.0   0.0   0.0
      vertex    1.0   1.0   1.0
      vertex    1.0   0.0   1.0
    endloop
  endfacet
  facet normal  0.0  -1.0   0.0    
    outer loop
      vertex    0.0   0.0   0.0
      vertex    1.0   0.0   0.0
      vertex    1.0   0.0   1.0
    endloop
  endfacet
  facet normal  0.0  -1.0   0.0    
    outer loop
      vertex    0.0   0.0   0.0
      vertex    1.0   0.0   1.0
      vertex    0.0   0.0   1.0
    endloop
  endfacet
  facet normal  0.0   0.0   1.0    
    outer loop
      vertex    0.0   0.0   1.0
      vertex    1.0   0.0   1.0
      vertex    1.0   1.0   1.0
    endloop
  endfacet
  facet normal  0.0   0.0   1.0    
    outer loop
      vertex    0.0   0.0   1.0
      vertex    1.0   1.0   1.0
      vertex    0.0   1.0   1.0
    endloop
  endfacet
endsolid MYSOLID

The same cube imported in Tinkercad

A sphere would then be composed of hundreds, if not thousands, of triangles depending on the precision of its surface. Luckily, there is software to calculate this!

3D Printing at the Library

Did you know? Your library offers low-cost 3D printing services!

Loyal to our mission to support teaching and research, we want to make this innovative technology accessible for its high educational and social potential.

Visit the 3D Printing page for more information.

For more information

PolyFab, Polytechnique Montréal’s Fab Lab, gave a conference/workshop at the Library on 3D modelling in April 2015.

Consult the PDF version of this presentation.

Resources

Off-Campus Access to Documents

If you are a member (student, professor, researcher, employee, etc.) of the Polytechnique Montréal community, you can access all of the Library's paid electronic resources from off-campus. You just need to configure your browser's proxy server settings.