SKIN

The skinned frame acts itself as a joint. I call it ‘root’ here.

SKIN (v29)

In Mafia, mesh vertices are sorted by joint id and weight.
Joint 1 fully weighted vertices (1.0 weight)
Joint 1 weighted vertices
Joint 2 fully weighted vertices (1.0 weight)
Joint 2 weighted vertices
…
Root fully weighted vertices (1.0 weight)

lods        SKIN_LOD[mesh.numLods]
  numJoints   uint8
  numW1Verts  uint32
  min         vector3
  max         vector3
  joints      SKIN_JOINT[numJoints]
    matrix      matrix4
    numW1Verts  uint32
    numWeights  uint32
    parentId    uint32
    min         vector3
    max         vector3
    weights     float[numWeights]

  • lods (SKIN_LOD[]) - array of SKIN_LOD

  • numJoints (uint8)

  • numW1Verts (uint32) - number of verts with 1.0 weight influenced by root, at the end of vertex buffer

  • min, max (vector3) - bounding box of verts affected by this (root) joint, in local space

  • joints (SKIN_JOINT[]) - array of SKIN_JOINT

  • joint.matrix (matrix4)

  • joint.numW1Verts (uint32) - number of verts with 1.0 weight

  • joint.numWeights (uint32) - number of explicitly defined weights

  • joint.parentId (uint32) - 1-based parent joint id, 0 = root

  • joint.min, joint.max (vector3) - bounding box of verts affected by this joint, in local space

  • joint.weights (float[]) - array of float

Every vertex should be described - sum of all numW1Verts for root and numW1Verts and numWeights for each joint should be equal to number of mesh vertices.

SKIN (v41, v42)

v41 uses vector4, v42 uses vector3

numJoints   uint8
min         vector4/vector3
max         vector4/vector3
parentIds   uint8[numGroups]      0 = root
joints      JOINT[numGroups]
  matrix      matrix4
  min         vector4/vector3
  max         vector4/vector3
lods        LOD[mesh.numLods]
  numWeights  uint32
  weights     WEIGHT[numWeights]
    boneId      uint8
    weight      uint8