Triangle Mesh

Triangle mesh collision shape. More...

Collaboration diagram for Triangle Mesh:

Data Structures
struct	b3MeshDef
	This is used to create a re-usable collision mesh. More...
struct	b3MeshTriangle
	A mesh triangle. More...
struct	b3MeshNode
	A mesh BVH node. More...
struct	b3MeshData
	This is a sorted triangle collision bounding volume hierarchy. More...
struct	b3Mesh
	This allows mesh data to be re-used with different scales. More...
union	b3MeshNode.data
	Anonymous union. More...
struct	b3MeshNode.data.asNode
	Internal node. More...
struct	b3MeshNode.data.asLeaf
	Leaf node. More...

Macros
#define	B3_MESH_VERSION   0xABD11AB62A6E886Dull
	64-bit mesh version. Useful for validating serialized data.

Enumerations
enum	b3MeshEdgeFlags {   b3_concaveEdge1 = 0x01 , b3_concaveEdge2 = 0x02 , b3_concaveEdge3 = 0x04 , b3_inverseConcaveEdge1 = 0x10 ,   b3_inverseConcaveEdge2 = 0x20 , b3_inverseConcaveEdge3 = 0x40 , b3_allConcaveEdges = b3_concaveEdge1 | b3_concaveEdge2 | b3_concaveEdge3 , b3_flatEdge1 = b3_concaveEdge1 | b3_inverseConcaveEdge1 ,   b3_flatEdge2 = b3_concaveEdge2 | b3_inverseConcaveEdge2 , b3_flatEdge3 = b3_concaveEdge3 | b3_inverseConcaveEdge3 , b3_allFlatEdges = b3_flatEdge1 | b3_flatEdge2 | b3_flatEdge3 }
	Triangle mesh edge flags.

Functions
const b3MeshNode *	b3GetMeshNodes (const b3MeshData *mesh)
	Get read only mesh BVH nodes.
const b3Vec3 *	b3GetMeshVertices (const b3MeshData *mesh)
	Get read only mesh vertices.
const b3MeshTriangle *	b3GetMeshTriangles (const b3MeshData *mesh)
	Get read only mesh triangles.
const uint8_t *	b3GetMeshMaterialIndices (const b3MeshData *mesh)
	Get read only mesh materials. The count is equal to the triangle count.
const uint8_t *	b3GetMeshFlags (const b3MeshData *mesh)
	Get read only mesh flags. The count is equal to the triangle count.
b3MeshData *	b3CreateGridMesh (int xCount, int zCount, float cellWidth, int materialCount, bool identifyEdges)
	Create a grid mesh along the x and z axes.
b3MeshData *	b3CreateWaveMesh (int xCount, int zCount, float cellWidth, float amplitude, float rowFrequency, float columnFrequency)
	Create a wave mesh along the x and z axes.
b3MeshData *	b3CreateTorusMesh (int radialResolution, int tubularResolution, float radius, float thickness)
	Create a torus mesh.
b3MeshData *	b3CreateBoxMesh (b3Vec3 center, b3Vec3 extent, bool identifyEdges)
	Create a box mesh.
b3MeshData *	b3CreateHollowBoxMesh (b3Vec3 center, b3Vec3 extent)
	Create a hollow box mesh.
b3MeshData *	b3CreatePlatformMesh (b3Vec3 center, float height, float topWidth, float bottomWidth)
	Create a platform mesh. A truncated pyramid.
b3MeshData *	b3CreateMesh (const b3MeshDef *def, int *degenerateTriangleIndices, int degenerateCapacity)
	Create a generic mesh.
void	b3DestroyMesh (b3MeshData *mesh)
	Destroy a mesh.
int	b3GetHeight (const b3MeshData *mesh)
	Get the height of the mesh BVH.

Detailed Description

Triangle mesh collision shape.

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Data Structure Documentation

b3MeshDef

struct b3MeshDef

This is used to create a re-usable collision mesh.

Collaboration diagram for b3MeshDef:

Data Fields
bool	identifyEdges	Compute triangle adjacency information using shared edges.
int32_t *	indices	Triangle vertex indices. 3 for each triangle.
uint8_t *	materialIndices	Triangle material index. 1 per triangle. Indexes into b3ShapeDef::materials. This allows different run-time material data to be associated with different instances of this mesh.
int	triangleCount	The triangle count. Must be 1 or more.
bool	useMedianSplit	Use the median split instead of SAH to speed up mesh creation. Good for meshes that are structured like a grid.
int	vertexCount	The vertex count. Must be 3 or more.
b3Vec3 *	vertices	Triangle vertices.
float	weldTolerance	Tolerance for vertex welding in length units.
bool	weldVertices	Optionally weld nearby vertices.

b3MeshTriangle

struct b3MeshTriangle

A mesh triangle.

Data Fields
int32_t	index1	Index of vertex 1.
int32_t	index2	Index of vertex 2.
int32_t	index3	Index of vertex 3.

b3MeshData

struct b3MeshData

This is a sorted triangle collision bounding volume hierarchy.

Note

This struct has data hanging off the end and cannot be directly copied.

Collaboration diagram for b3MeshData:

Data Fields
b3AABB	bounds	Local axis-aligned box.
int	byteCount	The total number of bytes for this mesh.
int	degenerateCount	The number of degenerate triangles. Diagnostic.
int	flagsOffset	Offset of the triangle flag array in bytes from the struct address.
uint32_t	hash	Hash of this mesh (this field is zero when the hash is computed).
int	materialCount	The number of materials.
int	materialOffset	Offset of the material array in bytes from the struct address.
int	nodeCount	The number of BVH nodes.
int	nodeOffset	Offset of the node array in bytes from the struct address.
float	surfaceArea	Combined surface area of all triangles. Single-sided.
int	treeHeight	The height of the bounding volume hierarchy.
int	triangleCount	The number of triangles.
int	triangleOffset	Offset of the triangle array in bytes from the struct address.
uint64_t	version	Version must be first.
int	vertexCount	The number of vertices.
int	vertexOffset	Offset of the vertex array in bytes from the struct address.

b3Mesh

struct b3Mesh

This allows mesh data to be re-used with different scales.

Collaboration diagram for b3Mesh:

Data Fields
const b3MeshData *	data	Immutable pointer to the mesh data.
b3Vec3	scale	This scale may be non-uniform and have negative components. However, no component may be very small in magnitude.

b3MeshNode.data.asNode

struct b3MeshNode.data.asNode

Internal node.

Data Fields
uint32_t	axis: 2	Split axis. 0, 1, or 2.
uint32_t	childOffset: 30	Offset of the second child node.

b3MeshNode.data.asLeaf

struct b3MeshNode.data.asLeaf

Leaf node.

Data Fields
uint32_t	triangleCount: 30	The number of triangles for this leaf node.
uint32_t	type: 2	Aligned with axis above and has value of 3 if this is a leaf.

Function Documentation

b3CreateGridMesh()

b3MeshData * b3CreateGridMesh	(	int	xCount,
		int	zCount,
		float	cellWidth,
		int	materialCount,
		bool	identifyEdges )

Create a grid mesh along the x and z axes.

Parameters

xCount	the number of rows in the x direction
zCount	the number of rows in the z direction
cellWidth	the width of each cell
materialCount	the number of materials to generate
identifyEdges	compute adjacency information