Game Opcodes:Party Map Marker Update

Shows party members on the map when the client receives the packet while the map is open.

Data

Offset	Data Type	Length	Variable	Description
0x00	uint64	8 Bytes	playerGroupID	The party group to be assigned to the player.
0x08	uint32	4 Bytes	groupType	The type of group. Retail always showing PlayerPartyGroup (10001)
0x10	markerData[15]	640 Bytes	markerData	Contains the information of each player noted in the array
0x290	uint32	4 Bytes	numEntries	Amount of entries in the array

markerData - Index length 40 bytes, 16 indices max
Offset	Data Type	Length	Variable	Description
0x00	uint32	4 Bytes	playerID	The ID of a player in the group
0x08	uint32	4 Bytes	unknown	Each player has a different value assigned here. Unknown use case
0x14	uint32	4 Bytes	playerX	X position of the player. Floating point value.
0x18	uint32	4 Bytes	playerY	Y position of the player. Floating point value.
0x1C	uint32	4 Bytes	playerZ	Z position of the player. Floating point value.
0x20	uint32	4 Bytes	playerO	Orientation of the player. Floating point value.

Sent from the server at a regular interval, likely due to client not being programmed to send a request for such data when the player opens the map.