Clustered Mesh

ClusteredMesh
aka CollisionMeshData
Track unit 203's clustered mesh.
Resource names	Unknown
Type ID	0x24
Category	Generic
Memory distribution	Main Memory only
Imports	Unknown
Imported by	ID List
Editor available?	Viewer only Use Blender addons

Development
Information on versions of the Clustered Mesh resource type used during development.

Clustered Mesh resources were used for world collision (WORLDCOL) prior to the introduction of the Polygon Soup List resource type.

Structures

CgsPhysics::CollisionMeshData

32-bit

Offset	Length	Type	Name	Description
0x0	0x4	Volume*	mpCollisionVolume
0x4	0xC			Padding
0x10	0x10	Vector3Plus	mBoundingSphere

rw::collision::Volume

32-bit

Offset	Length	Type	Name	Description	Comments
0x0	0x40	Matrix44Affine	transform
0x40	0x4	Volume::VTable*	vTable		When written to file, this actually represents an `rw::collision::VolumeType` instead rather than a pointer. This is always `VOLUMETYPEAGGREGATE`, which has a value of 6.
0x44	0x4	ClusteredMesh*			This is actually implemented as a 12-byte union accepting multiple types, including three floats representing triangles or boxes. The union type used is defined by the `VolumeType` in the vTable. The Clustered Mesh resource type however only accepts a ClusteredMesh pointer here (represented by the aggregate volume type), and will cause undefined behaviour if other types are used instead.
0x48	0x8			Union padding
0x50	0x4	float32_t	radius
0x54	0x4	uint32_t	groupID
0x58	0x4	uint32_t	surfaceID
0x5C	0x4	uint32_t	m_flags		See VolumeFlag

rw::collision::VolumeFlag

Note that this is sourced from February 2007 data and may or may not have changed in later versions.

Name	Value	Comments
VOLUMEFLAG_ISENABLED	1
VOLUMEFLAG_TRIANGLENORMALISDIRTY	2
VOLUMEFLAG_TRIANGLEONESIDED	16	These precise values (but not the existence of the flags themselves) are technically platform-specific and is documented for PS3. It may or may not be actually different on other platforms.
VOLUMEFLAG_TRIANGLEEDGE0CONVEX	32
VOLUMEFLAG_TRIANGLEEDGE1CONVEX	64
VOLUMEFLAG_TRIANGLEEDGE2CONVEX	128
VOLUMEFLAG_TRIANGLEUSEEDGECOS	256
VOLUMEFLAG_TRIANGLEVERT0DISABLE	512
VOLUMEFLAG_TRIANGLEVERT1DISABLE	1024
VOLUMEFLAG_TRIANGLEVERT2DISABLE	2048
VOLUMEFLAG_FORCEENUMSIZEINT	0x7FFFFFFF

rw::collision::Aggregate

32-bit

Offset	Length	Type	Name	Comments
0x0	0x20	AABBox	m_AABB
0x20	0x4	Aggregate::VTable*	m_vTable	Garbage data in the file - always replaced on read
0x24	0x4	uint32_t	m_numTagBits
0x28	0x4	uint32_t	m_numVolumes
0x2C	0x4	uint32_t	pad

rw::collision::Procedural

32-bit

Offset	Length	Type	Name	Description	Comments
0x0	0x30	Aggregate		Base class

rw::collision::ClusteredMesh

The base pointer resets here - all pointer offsets here are relative to the start of this struct.

32-bit

Offset	Length	Type	Name	Description	Comments
0x0	0x30	Procedural		Base class
0x30	0x4	KDTree*	mKDTree
0x34	0x4	uint32_t*	mCluster		Effectively a ClusteredMeshCluster**
0x38	0x8	ClusterParams	mClusterParams
0x40	0x4	uint32_t	mNumClusters
0x44	0x4	uint32_t	mMaxClusters
0x48	0x4	uint32_t	mNumUnits
0x4C	0x4	uint32_t	mMaxUnits
0x50	0x4	uint32_t	mSizeOfThis
0x54	0x2	uint16_t	mDefaultGroupId
0x56	0x2	uint16_t	mDefaultSurfaceId
0x58	0x1	uint8_t	mDefaultEdgeAngle
0x59	0x7			Padding

rw::collision::AALineClipper::AABBox

Offset	Length	Type	Name	Description	Comments
0x0	0x10	vpu::Vector3	m_min
0x10	0x10	vpu::Vector3	m_max

rw::collision::ClusterParams

Offset	Length	Type	Name	Description	Comments
0x0	0x4	float32_t	mVertexCompressionGranularity		Relevant for cluster compression modes 1 and 2
0x4	0x2	uint16_t	mFlags		Likely CMFlags
0x6	0x1	uint8_t	mGroupIdSize	Number of bytes	1 or 2
0x7	0x1	uint8_t	mSurfaceIdSize	Number of bytes	1 or 2

rw::collision::CMFlags

Note that this is sourced from February 2007 data and may or may not have changed in later versions.

Name	Value	Comments
CMFLAG_INT16VERTEX	1
CMFLAG_INT16NORMAL	2
CMFLAG_20BITCLUSTERINDEX	4
CMFLAG_ONESIDED	16
CMFLAG_FORCEENUMSIZEINT	0x7FFFFFFF

rw::collision::KDTree

The base pointer resets here - all pointer offsets here are relative to the start of this struct.

32-bit

Offset	Length	Type	Name	Description
0x0	0x4	BranchNode*	m_branchNodes
0x4	0x4	uint32_t	m_numBranchNodes
0x8	0x4	uint32_t	m_numEntries
0xC	0x4			Padding
0x10	0x20	AABBox	m_bbox

rw::collision::KDTree::BranchNode

Offset	Length	Type	Name
0x0	0x4	uint32_t	m_parent
0x4	0x4	uint32_t	m_axis
0x8	0x10	NodeRef[2]	m_childRefs
0x18	0x8	float32_t[2]	m_extents

rw::collision::KDTree::NodeRef

Offset	Length	Type	Name	Description	Comments
0x0	0x4	uint32_t	m_content
0x4	0x4	uint32_t	m_index

rw::collision::ClusteredMeshCluster

Offset

Length

Type

Name

Description

Comments

0x0

0x2

uint16_t

unitCount

0x2

uint16_t

unitDataSize

0x4

0x2

uint16_t

unitDataStart

The index of the vertex array where unit data starts

0x6

0x2

uint16_t

normalStart

The index of the vertex array where normal data starts

0x8

0x2

uint16_t

totalSize

0xA

0x1

uint8_t

vertexCount

0xB

0x1

uint8_t

normalCount

0xC

0x1

uint8_t

compressionMode

VERTICES_UNCOMPRESSED = 0
VERTICES_16BIT_COMPRESSED = 1
VERTICES_32BIT_COMPRESSED = 2

0xD

0x3

uint8_t[3]

Padding

0x10

vpu::Vector3[1]

vertexArray

Variable size data

Hmmm...

To do:
Normals?

Vertex data
Unit data

Vertex data

VERTICES_UNCOMPRESSED
Offset	Length	Type	Name	Comments
0x0 (repeating)	0x10	vpu::Vector3		Raw vector (mVertexCompressionGranularity unused)

VERTICES_16BIT_COMPRESSED
Offset	Length	Type	Name	Comments
0x0	0xC	int32_t[3]	vertexOffsetData	Component base
0xC (repeating)	0x6	Vertex16[3]	vertData	Add to initial int32_t components and then multiply components by mVertexCompressionGranularity to get coordinate

VERTICES_32BIT_COMPRESSED
Offset	Length	Type	Name	Comments
0x0 (repeating)	0xC	Vertex32[3]	vertData	Multiply components by mVertexCompressionGranularity to get coordinate

rw::collision::ClusteredMeshCluster::Vertex16

Offset	Length	Type	Name
0x0	0x2	uint16_t	x
0x2	0x2	uint16_t	y
0x4	0x2	uint16_t	z

rw::collision::ClusteredMeshCluster::Vertex32

Offset	Length	Type	Name
0x0	0x4	int32_t	x
0x4	0x4	int32_t	y
0x8	0x4	int32_t	z

Unit data

This is a byte stream. Exact offsets are variable and depends on several factors, as detailed below.

Length	Type	Description	Comments
0x1	uint8_t	Lower nibble (type) [unused] UNITTYPE_OLDTRIANGLE = 0 UNITTYPE_TRIANGLE = 1 UNITTYPE_QUAD = 2 UNITTYPE_TRILIST = 3 Upper nibble (flags) UNITFLAG_NORMAL = 1 UNITFLAG_EDGEANGLE = 2 UNITFLAG_GROUPID = 4 UNITFLAG_SURFACEID = 8 [unused] UNITFLAG_USEOLDTRI = all bits set (including type)
0x1	uint8_t	Only present if type == UNITTYPE_TRILIST Triangle count	For UNITTYPE_OLDTRIANGLE/UNITTYPE_TRIANGLE this is implicitly 1 and for UNITTYPE_QUAD this is implicitly 2
Vertex count (triangle count + 2)	uint8_t	Vertex index
0x1	uint8_t	Only present with UNITFLAG_NORMAL Normal index probably
Edge count (triangle count + 2)	uint8_t	Only present with UNITFLAG_EDGEANGLE Edge cosines? Mask with 0x1F and flags above that? rw::colison::UnitEdgeFlags is likely relevant
Group ID size (see ClusterParams)	uint8_t or uint16_t	Only present with UNITFLAG_GROUPID Group ID	This is always little endian.
Surface ID size (see ClusterParams)	uint8_t or uint16_t	Only present with UNITFLAG_SURFACEID Surface ID	This is always little endian.