Snapping and the grid
The planner has two snapping behaviours. Both are on by default, both can be toggled, and they don't fight each other — connector snap takes priority whenever the cursor is near a free end.
Connector snap
When the cursor is near a free connector on an existing piece, the ghost rotates so its leading connector mates end-to-end with the target. Two connectors mate when:
- They face each other (their headings differ by exactly 180°), and
- Their
connector_typestrings match exactly (no fuzzy matching across track systems).
If a snap looks wrong, check both conditions. The most common case is mismatched connector types — Hornby Setrack and Jouef look similar but their geometry differs, and the planner won't pretend otherwise. Use a transition piece if you need to bridge two systems.
Grid snap
When the ghost isn't near a free connector, it falls back to grid snap. The grid is set per layout (typically 10 mm or 25 mm in true millimetres) and the ghost rounds its position to the nearest grid intersection. The same applies when you drag a piece that's already placed: if it doesn't snap to a connector, its position rounds to the grid (the rest of the group moving with it).
Press G (or click the grid toggle in the top bar) to turn grid snap off. When it's off, the ghost follows the cursor pixel-precisely. The grid lines themselves stay visible — they're a visual reference even when snap is off.
The infinite grid
The grid is rendered as an infinite plane in 2D mode. Pan as far as you want — the grid keeps drawing. There's no "edge of the canvas". The minimap and home chevron will help you find your way back to your layout if you wander.
The grid spacing adapts to your zoom so the lines stay a legible size on screen. At normal zoom it's the familiar 100 mm cell with a bolder line every 500 mm; as you zoom in the spacing steps down — 50, 20, 10, 5, 2 mm — to a 1 mm graph-paper grid up close, and coarser as you zoom out. Zoom is bounded to that range — out until the 10 m grid appears, in until the 1 mm grid — so the view doesn't scroll endlessly into empty space. It's a visual aid only; it doesn't change where pieces snap (that's set by the grid snap step).
A scale bar in the bottom-left corner reads the current zoom as a round real-world distance (mm / cm / m), like the scale on a map — handy for eyeballing how much room a run of track will take.