Crate repame_nav 

Spatial navigation for Repame: a heightfield navmesh you bake from the engine’s own collision input, A* path queries over the region graph, funnel (string-pull) corridors, and path-following agents with reciprocal velocity obstacle avoidance. Both 2D (glam::Vec2) and 3D (glam::Vec3) meshes share one implementation.

Pipeline

1. Implement Source2d or Source3d (any repame_physics::VoxelQuery is a Source3d) and call bake_2d or bake_3d to get a NavMesh.
2. Query with NavMesh::find_path, or wrap the mesh in a NavMap to layer dynamic NavObstacles and off-mesh NavLinks on top.
3. Drive a NavigationAgent with the returned path.

Determinism

Bakes emit regions in row-major cell order and deduplicate shared corners, so vertex numbering is fixed. Adjacency and path results never iterate a hash map; A* breaks cost ties by polygon index and the funnel is order-stable. Obstacles and links are read in insertion order, and the avoidance resolver samples a fixed fan around sorted neighbours. Within one binary, the same inputs give bit-identical output. Cross-target float equality (native libm vs wasm, notably sqrt/sin_cos) is not claimed, the same caveat as [repame_sim]: hash a trace and diff to prove it.

use repame_nav::{bake_2d, Bake2d, Source2d};
use glam::Vec2;

struct Open;
impl Source2d for Open {
    fn is_solid(&self, _cell: [i32; 2]) -> bool { false }
}

let mesh = bake_2d(&Open, &Bake2d { min: [0, 0], max: [4, 4], cell_size: 1.0, agent_radius: 0.0 })
    .expect("open field bakes");
let path = mesh.find_path(Vec2::new(0.5, 0.5), Vec2::new(3.5, 3.5)).expect("connected");
assert_eq!(path.len(), 2);

Structs

AgentNeighbor

Another agent seen by the avoidance resolver.

AvoidanceConfig

Tuning for resolve.

Bake2d

2D bake parameters. min is inclusive, max exclusive.

Bake3d

3D bake parameters. min is inclusive, max exclusive; a voxel is one world unit.

NavLink

A one-way or bidirectional off-mesh connection between two world points.

NavMap

A baked mesh plus the dynamic data layered on top of it for queries.

NavMesh

A navigation mesh: vertices plus convex polygon regions plus adjacency.

NavObstacle

A dynamic carved region, in navigation-plane coordinates.

NavigationAgent

Follows a path returned by NavMesh::find_path or NavMap::find_path.

Neighbor

The region across one directed edge of a polygon.

Neighbor2

A neighbour in the navigation plane.

Polygon

One convex region, stored as indices into the mesh vertex buffer.

Enums

NavError

A navigation setup or query refused to build.

Constants

VOXEL

Unit horizontal size of one voxel column, in world units.

Traits

NavVec

A point or vector a navmesh can be built from: glam::Vec2 for flat 2D navigation, glam::Vec3 for a 3D heightfield.

Source2d

2D solidity sampler: a cell is either solid or free.

Source3d

3D collision sampler: solidity plus the top surface height behind a cell (ramps live behind Source3d::surface_top).

Functions

bake_2d

Bake a flat 2D navmesh of unit squares from a solidity sampler.

bake_3d

Bake a heightfield 3D navmesh from a collision sampler.

funnel

Pull a straight path through an ordered list of portal segments.

resolve

Resolve desired against nearby agents. Returns the chosen velocity.