Module mesh 

Triangle mesh collision shape.

Port of box3d-cpp-reference/src/mesh.c and the mesh group of include/box3d/types.h / collision.h.

Layout:

• types — MeshDef/Data/Node/Triangle, edge flags, blob serialization
• bvh — vertex welding, SAH/median BVH build, DFS triangle sort
• create — create/destroy, edge identification, validation
• factory — grid/wave/torus/box/hollow/platform helpers
• cast — AABB, ray cast, shape cast
• query — overlap, query, mover collide, triangle accessor

Deferred: world shape attach.

SPDX-FileCopyrightText: 2026 Erin Catto SPDX-License-Identifier: MIT

Structs

Mesh

Mesh data re-used with different scales. (b3Mesh)

MeshData

Sorted triangle collision bounding volume hierarchy. (b3MeshData)

MeshDef

Data used to create a re-usable collision mesh. (b3MeshDef)

MeshNode

A mesh BVH node. (b3MeshNode)

MeshTriangle

A mesh triangle. (b3MeshTriangle)

Constants

ALL_CONCAVE_EDGES

ALL_FLAT_EDGES

CONCAVE_EDGE1

Triangle mesh edge flags. (b3MeshEdgeFlags)

CONCAVE_EDGE2

CONCAVE_EDGE3

FLAT_EDGE1

FLAT_EDGE2

FLAT_EDGE3

INVERSE_CONCAVE_EDGE1

INVERSE_CONCAVE_EDGE2

INVERSE_CONCAVE_EDGE3

LEAF_NODE

Leaf node type tag in the packed node bitfield. (B3_LEAF_NODE)

MESH_DATA_SIZE

Size of the C b3MeshData header.

MESH_NODE_SIZE

Size of the C b3MeshNode.

MESH_STACK_SIZE

BVH traversal stack size. (B3_MESH_STACK_SIZE)

MESH_TRIANGLE_SIZE

Size of the C b3MeshTriangle.

MESH_VERSION

64-bit mesh version. (B3_MESH_VERSION)

Functions

collide_mover_and_mesh

Collide a capsule mover against a mesh, writing contact planes. (b3CollideMoverAndMesh)

compute_mesh_aabb

Compute the AABB of a mesh. (b3ComputeMeshAABB)

convert_bytes_to_mesh

Restore a mesh from a contiguous blob. (inverse of MeshData::to_bytes)

create_box_mesh

Create a box mesh. (b3CreateBoxMesh)

create_grid_mesh

Create a grid mesh along the x and z axes. (b3CreateGridMesh)

create_hollow_box_mesh

Create a hollow (inward-facing) box mesh. (b3CreateHollowBoxMesh)

create_mesh

Create a mesh from a definition. (b3CreateMesh)

create_platform_mesh

Create a platform mesh (truncated pyramid). (b3CreatePlatformMesh)

create_torus_mesh

Create a torus mesh. (b3CreateTorusMesh)

create_wave_mesh

Create a wave mesh along the x and z axes. (b3CreateWaveMesh)

destroy_mesh

Destroy a mesh (no-op drop for owned Rust data). (b3DestroyMesh)

get_height

Height of the mesh BVH. (b3GetHeight)

get_mesh_flags

Mesh triangle flags. (b3GetMeshFlags)

get_mesh_material_indices

Mesh material indices. (b3GetMeshMaterialIndices)

get_mesh_nodes

Mesh nodes. (b3GetMeshNodes)

get_mesh_triangle

Get a scaled mesh triangle with edge flags. (b3GetMeshTriangle)

get_mesh_triangles

Mesh triangles. (b3GetMeshTriangles)

get_mesh_vertices

Mesh vertices. (b3GetMeshVertices)

is_valid_mesh

Validate mesh version and size. (b3IsValidMesh)

overlap_mesh

Test overlap between a mesh and a shape proxy. (b3OverlapMesh)

query_mesh

Query mesh triangles overlapping an AABB. Callback receives (a, b, c, triangle_index) and may return false to stop early. (b3QueryMesh)

ray_cast_mesh

Ray cast versus a mesh in local space. (b3RayCastMesh)

shape_cast_mesh

Shape cast versus a mesh in local space. (b3ShapeCastMesh)