raygeo.geo.algo.nest2d.gravity

Gravity optimization for nesting layouts.

Provides binary-search gravity sliding to tighten packing by sliding parts down and left as far as possible without overlapping.

Functions

apply_gravity()

apply_gravity(
    placement_groups: Sequence[Sequence[types.Polygon]],
    sheet_poly: types.Polygon,
    spacing: float,
) -> list[tuple[float, float]]

Apply gravity sliding to tighten a nesting layout.

Iterates Y and X passes until no movement occurs (max 10 passes). Returns a (dx, dy) adjustment for each input group in order.

Parameter	Type	Description
placement_groups	Sequence[Sequence[types.Polygon]]	List of placed parts (each a list of polygons).
sheet_poly	types.Polygon	Sheet polygon.
spacing	float	Minimum spacing between parts.
Returns	list[tuple[float, float]]	List of (dx, dy) adjustments, one per group.
Complexity		O(passes * n * m) where passes ≤ 10.

Gravity tightening: before vs after

find_max_slide()

find_max_slide(
    polys: Sequence[types.Polygon],
    other_polys_list: Sequence[Sequence[types.Polygon]],
    sheet_bounds: tuple[float, float, float, float],
    sheet_poly: types.Polygon,
    axis: str,
    spacing: float,
) -> float

Find the maximum distance a part can slide in the negative axis direction.

Uses binary search with polygon overlap and containment checks.

Parameter	Type	Description
polys	Sequence[types.Polygon]	Polygons of the part to slide.
other_polys_list	Sequence[Sequence[types.Polygon]]	Polygons of all other placed parts (grouped).
sheet_bounds	tuple[float, float, float, float]	Sheet bounding box (min_x, min_y, max_x, max_y).
sheet_poly	types.Polygon	Sheet polygon.
axis	str	"x" or "y" — axis to slide along.
spacing	float	Minimum spacing between parts.
Returns	float	Maximum slide distance.
Complexity		O(log range * n * m) for binary search with overlap checks.