Slicing

Slicing is the act of converting a 3D model into a set of instructions for 3D printers. A slicer software converts a 3D model into commands in either a bottom-up, top-down, or left-to-right manner. In a slicer, these specific settings can be controlled:

• printing settings
• filament/resin settings
• printer settings

The main functions of a slicing software are to :

• store a visual image of the 3D model (the surface geometry of the model)
• read the 3D file with the model
• slice the model into layers and determine the tool path to print the object
  • for FDM:
    • write the g-code, which is a set of commands to execute the print action (instructions to the printer about the movement in the 3 axes that have to be performed)
  • for SLA (depending on the approach):
    • create commands for the laser to execute the curing action
    • create a series of instructions for the LCD panel, to block the UV radiation from curing at specific positions
    • create a series of instructions for the DMD microchip, to direct the UV light on specific positions

The slicing process is influenced by the resolution of the printer, the layer thickness, and the additional antialiasing settings chosen when slicing.

Layer thickness indicates how many slices you need to print an object. If you print a scene that is 6cm high and you decide on a 50 μm layer thickness, the program generates 1200 slices. Whereas using a 30 μm layer thickness results in 2000 slices.

Antialiasing adds extra calculations, as it adds a grayscale to the slices (normally represented by black and white pixels). The grayscale causes the UV light to cure partly the indicated area, which creates a smoothness on the surface of the object.

Please note that printers above 8k resolution don’t need antialiasing to get great results. Keeping the layer height at 30um should give you comparable results. This is beneficial to remove extra antialiasing calculations and speed up the slicing process.