Interpreting Slicer Output

Prev: Part 12: Slicing Process

This step explains what the slicer produces and how to validate it. PyMFCAD outputs everything needed to reproduce the print: the design metadata, settings, and image stack.

What the slicer writes

When you run slicer.make_print_file(), you should get:

  1. Output folder named after your filename (or a ZIP if zip_output=True).
  2. Slices folder containing 8-bit grayscale images (one per layer unless minimized).
  3. JSON print file that follows the PyMFCAD print schema.
  4. Recompile-ready metadata (all python code needed to regenerate the stack).

Checkpoint: You should see a folder containing a JSON file and a slices/ directory with image files.

Slices folder (8-bit grayscale)

The slicer outputs one image per layer in 8-bit grayscale:

  • Black (0) = no exposure
  • White (255) = full exposure
  • Gray values = partial exposure (dose modulation, not currently used. Use images/exposure times instead)

If your device uses multiple exposures per layer (e.g., secondary dose or membranes), you may see multiple images per layer in the settings JSON’s image list.

Checkpoint: Each image is 8-bit grayscale. There may be more or less images than layers in the JSON.

JSON print file (schema-defined)

The JSON file is the single source of truth for the print job. It conforms to the schema published to our repository.

If you want a human-readable walkthrough, see the JSON print file reference.

At a high level, it contains:

  • Header: schema version, image directory, and print flags
  • Design: user, purpose, resin, printer, slicer metadata
  • Default layer settings: global position and exposure defaults
  • Layers: per-layer overrides (if any)

Checkpoint: The JSON should include a Header, Design, and Default layer settings section.

Minimization (file size reduction)

If you enabled minimize_file=True, the slicer may store reduced images to save space. This does not change the printed geometry, only the representation.

Checkpoint: Minimization should reduce the output size without changing the visible geometry when viewed in a slicer or preview tool.

Quick validation checklist

  • Confirm the image directory in JSON matches your slices folder name.
  • Verify that default exposure/position settings are present.
  • If you set burn-in, check that early layers have longer exposure times.

Next: Part 14: Configuring Regional Settings