Vmaps stands for MaNGOS WoW Vertex Map Physics Info and are used to implement vertical clipping related issues. They are required for spells, which require the caster to have its target in line of sight and random movement generators (fear for example).
They are extracted from the client and will be stored in a MaNGOS own format.
The generation takes place in two steps.
First, all important WMO files are exported from the MPQ files and written to the buildings subdirectory.
Additionally a file containing information about the positions of these WMOs in the world is generated from ADT files and will be written to the buildings folder.
In a second step, these information are assembled to .vmap and .vmdir file.
Extracted WMO format
The extracted wmo files in the Buildings subdirectory have a special format - they arenot to be mixed up with the client internal format of the same name.
byte magic "VMAPxxx" uint32 nVectors uint32 nGroups nGroups times: uint32 liqudflags uint32 "GRP " uint32 moba_size uint32 moba_batch uint32 mobaex uint32 "INDX" uint32 wsize uint32 nIndexes nIndexes times: float movt uint32 "VERT" uint32 wsize uint32 nVertices nVertices times: float vertice uint32 "LIQU" uint32 LiqExsize uint32 hlq_xverts uint32 hlq_yverts LiquidEx_size/4 times: float LiquidEx