Features

LayerForge converts 3D models into a series of SVG slice files. A stability driven algorithm places reference marks so the slices can be realigned during reassembly.

Marker Placement Workflow

1. Candidate selection – For each contour a set of candidate points is sampled. The :class:ReferenceMarkCalculator evaluates these points using a geometric stability metric (similar to GDOP) that rewards well‑spaced marks.
2. Inheritance – Marks from earlier slices are reused where possible. Their shape is preserved so that each layer shares a common set of identifiers.
3. Adjustment – After initial placement the marks are filtered by :class:ReferenceMarkAdjuster to ensure they do not overlap each other or sit too close to the contours.
4. Shape choice – A new mark takes the configured shape with the least symmetry: a triangle or an arrow (they have a direction), then a square, then a circle. Of two shapes with a direction the larger wins, so the defaults give the triangle. The order of the list does not matter. Every mark of a run has one angle, so one mark with a direction fixes the rotation of its piece.

This process results in clear reference markers that maintain alignment between layers without interfering with the slice geometry.

See Reference Mark Algorithm for a deeper look at the metric and adjustment steps.

Planned changes

The marks are meant to be holes that let a person stack the layers in exactly one way. That needs marks chosen per pair of adjacent layers, shapes chosen to fix rotation, and a check before any file is written. See Alignment requirements. The behavior above is what the tool does today.