Mesh library

Overview

Meshes are usually embedded into rigid model files (.3db and .cmp) with exception of UI where mesh data is stored in separate .vms file.

VMeshData

VMeshData is pretty much a big vertex/index buffer that contains all vertices and triangles of one or multiple parts. However when containing meshes of multiple parts VMeshData isn’t directly aware of how many has, it’s a dumb storage, but an indirect indication that another part begins within its data set is when VMeshGroup.vertexStart is 0 and when vertex index in triangle also starts from 0. Normally parts never share vertices, but mesh groups within a part may.

Name	Type	Description
meshType	uint32	Always 1. Game crashes otherwise.
primitiveType	uint32	Direct3D primitive type.
groupCount	uint16	Mesh group count.
indexCount	uint16	Element buffer count.
vertexFormat	uint16	Direct3D FVF (Flexible Vertex Format).
vertexCount	uint16	Vertex buffer count.
groups	varying	Mesh groups.
indices	varying	Element indices.
vertices	varying	Vertex attribute data.

• Element indices are uint16.
• Vertex attribute length depends on FVF mode.
• VMeshData can be mapped to OpenGL VAO (Vertex Array Object)

Primitive types are:

Value	Type
1	Point list
2	Line list
3	Line strip
4	Triangle list
5	Triangle strip
6	Triangle fan

These are vertex format flags and modes which Freelancer uses:

Name	Mask value	Description	Vertex value
D3DFVF_XYZ	0x0001	Position	float[3]
D3DFVF_NORMAL	0x0010	Normal	float[3]
D3DFVF_DIFFUSE	0x0040	Color	uint32
D3DFVF_TEXn	0xFF00	UV1-8	float[2]

• D3DFVF_XYZ, D3DFVF_NORMAL, D3DFVF_DIFFUSE and D3DFVF_TEX0 to D3DFVF_TEX8 supported.
• D3DFVF_PSIZE and D3DFVF_SPECULAR are not supported and will result in corrupted drawing.

A mesh group is a collection of vertices and vertex indices forming triangles that are grouped by a single material identifier. It is fairly common in Freelancer for a model or even an individual part of a compound model to use multiple materials. So a model or each of its parts may use one more groups if they use multiple materials.

Name	Type	Description
materialId	uint32	Material ID (FLCRC32 of material name).
vertexStart	uint16	Vertex buffer start index.
vertexEnd	uint16	Vertex buffer end index.
indexCount	uint16	Element buffer index count.
padding	uint16	Padding. Should be 0xCC.

VMeshRef

Pointer to chunk of data in VMeshData.

Name	Type	Description
size	uint32	VMeshRef byte size, always 60.
meshId	uint32	Mesh ID (FLCRC32 of VMeshData parent entry name).
vertexStart	uint16	Vertex buffer start index.
vertexCount	uint16	Vertex buffer index count.
indexStart	uint16	Element buffer start index.
indexCount	uint16	Element buffer index count.
groupStart	uint16	Mesh group start index.
groupCount	uint16	Mesh group count.
extents	float[6]	Bounding box as max and min of x, y and z.
center	float[3]	Bounding sphere center.
radius	float	Bounding sphere radius.

VWireData

Uses mesh vertices to construct lines for HUD wireframe view.

Name	Type	Description
size	uint32	VWireData header size, always 16.
meshId	uint32	Mesh ID.
vertexStart	uint16	Vertex buffer start index.
vertexCount	uint16	Unique vertex count.
indexCount	uint16	Element buffer index count.
vertexRange	uint16	Range between maximum vertex index and minimum vertex index.
indices	varying	A pair of element indices per line drawn.

• Like element indices in mesh these are uint16.
• There's a limit to how many indices a drawn wireframe model (including any attachments) can have.