1. 06 | End-to-End 3D Printing
Emmett Lalish | Mechanical Engineer
Kris Iverson | Lead Software Design Engineer

2. What is a Slicer? Slices 3D model into planar polygons
Fills polygons with toolpaths
Exports toolpaths as Gcode

3. Slicing is as much Art as Science
Infinitely many paths exist to construct any single 3D model
Best methods address physical hardware:
Exploit strengths
Hide weaknesses

4. Software Can Make Up for Hardware
Small objects get too hot and slump
Slow down on small areas to aid cooling
Extruder drools when stopped
Retract filament before traveling
Small arcs cause too much acceleration
Reduce speed based on radius of curvature

5. Why is Slicing so Hard? Common models have 105 – 106 faces
Model Parsing
Support Generation
Common models have 105 – 106 faces
Nonlinear transformations
Floating-point rounding errors
3D -> 2D Slice
Perimeter Inset
Surface Detection
Infill
Travel Optimization
Gcode Export

6. Manifoldness Does the mesh represent a solid?
Every edge much share exactly two faces
Those two faces must be oriented consistently

7. STL Ambiguities STL is currently the most common format for 3D models
30 year-old open standard
Mesh topology is lost in STL
Each face is stored separately
Reconstructing the manifold requires merging vertices with tolerance to account for rounding

8. 3MF Format 3D Manufacturing Format Compressed XML
Topological mesh storage
Manifoldness required
Support for colors, textures, materials
Metadata, thumbnail
Support for DRM
Extensible