VVD
VVD is the extension for Source's proprietary model vertex data format. It stores position independent flat data for the bone weights, normals, vertices, tangents and texture coordinates used by the MDL.
Header
struct vertexFileHeader_t
{
int id; // MODEL_VERTEX_FILE_ID -- little-endian "IDSV"
int version; // MODEL_VERTEX_FILE_VERSION
long checksum; // same as studiohdr_t, ensures sync
int numLODs; // num of valid lods
int numLODVertexes[MAX_NUM_LODS]; // num verts for desired root lod
int numFixups; // num of vertexFileFixup_t
int fixupTableStart; // offset from base to fixup table
int vertexDataStart; // offset from base to vertex block
int tangentDataStart; // offset from base to tangent block
};
Fixup Table
// apply sequentially to lod sorted vertex and tangent pools to re-establish mesh order
struct vertexFileFixup_t
{
int lod; // used to skip culled root lod
int sourceVertexID; // absolute index from start of vertex/tangent blocks
int numVertexes;
};
Vertex Data
A list of vertices follows the header
// NOTE: This is exactly 48 bytes
struct mstudiovertex_t
{
mstudioboneweight_t m_BoneWeights; //see below
Vector m_vecPosition;
Vector m_vecNormal;
Vector2D m_vecTexCoord;
};
// 16 bytes
struct mstudioboneweight_t
{
float weight[MAX_NUM_BONES_PER_VERT]; //MAX_NUM_BONES_PER_VERT is defined as 3
char bone[MAX_NUM_BONES_PER_VERT];
byte numbones;
};
Tangent Data
This seems to be an array of 4D vectors, one for each vertex
vec_t x, y, z, w;
