Dungeon Block Records contain the block data for dungeons. Each Dungeon Block Record describes one dungeon block, which fits into a two-dimensional grid with the other blocks of the dungeon. There are two connecting passages in each of the four cardinal directions, so there are eight paths leading out of each block. The architecture of the block, the doors, various action scripts and light sources, etc are all described here.
Each Dungeon Block Record begins with a letter and is followed by a 7-digit decimal integer. The name of Dungeon Block Records all terminate with the string ".RDB". Ex: "N0000019.RDB". These files are referenced in the dungeon records of MAPS.BSA.
Each Dungeon Block Record begins with a 20 byte long Header structure.
|4-7||UInt32||Width||The width of the dungeon.|
|8-11||UInt32||Height||The height of the dungeon.|
|12-15||UInt32||ObjectRootOffset||The offset from the beginning of the Dungeon Block Record to the ObjectRoot section.|
Following the Header structure, is a contiguous list of 750 ModelReference structures. This list must always be 750 elements long. Unused elements are filled with 0xff. Each element of the ModelReferenceList refers to an ARCH3D.BSA record via the ModelId field.
|0-4||7-bit ASCII string||ModelId||The RecordId of the ARCH3D.BSA record, as a five character string. This is not null-terminated.|
|5-7||7-bit ASCII string||Description||A short string describing the object. This is not null-terminated.|
Next is a contiguous list of 750 records, each 4 bytes long. They seem to correspond to the elements of the ModelReferenceList. The format of these bytes is unknown. Unused records are filled with 0x00.
The ObjectSection is a variably sized section containing a fixed-size header, a list of offsets to the Object structures, the Object structures, and any additional data such as Action structures.
|0-3||UInt32||UnknownOffset||An offset from the beginning of the RDB file to a linked list of unknown purpose and format.|
|16-19||UInt32||FileSize||The length of the Dungeon Block Record, in bytes.|
|20-51||UInt8[ 32 ]||Unknown4||Seem to always be 0xFF|
|52-55||7-bit ASCII string||Dagr||Seem to always be the string "DAGR", except in records N0000021.RDB, N0000041.RDB, N0000070.RDB, W0000006.RDB, S0000021.RDB, S0000141.RDB, S0000202.RDB, and S0000203.RDB.|
|56-511||UInt8[ 456 ]||Unknown5||Seem to be 0xFF|
This section is a contiguous list of Int32 values, RdbHeader.Width * RdbHeader.Height elements in count. Each entry is an offset to an Object structure. All offsets are relative from the beginning of the Dungeon Block Record. Negative values indicate no record is present. The meaning of the grid layout is unknown.
Following the ObjectRootList is a contiguous list of Object structures, in no particular order. Each Object structure is a node of a doubly linked list. Use the Object Roots Section to find the heads of the lists, and iterate using the Next and Previous fields of each head, to load the Object structures.
|0-3||Int32||Next||The offset from the beginning of the Dungeon Block Record to the next Object structure. A negative value indicates there are no more items.|
|0-7||Int32||Previous||The offset from the beginning of the Dungeon Block Record to the previous Object structure. A negative value indicates there are no previous items.|
|8-19||Point||Position||The Object's position in the scene.|
|20||ObjectType||Type||The specific type of the Object. See ObjectType enumeration below.|
|21-24||UInt32||Offset||The offset from the beginning of the Dungeon Block Record to the Object's Type-specific data.|
Each specific type must be decoded differently (see tables below), based on the Type field, according to the ObjectType enumeration below. The location of this data is reported by the Offset field.
|0x01||Model||A 3D model|
|0x02||LightSource||A light source|
|0x03||Flat||A Flat (including markers, junk, and monsters)|
At the location specified by the Object's Offset field, the object's type-specific data is found. Each of the three types must be decoded differently, but each is of a fixed size. The format is reported by the Object's Type field.
|0-11||Point||Rotation||The rotation angles about each axis, in Daggerfall Angles.|
|12-13||UInt16||ModelIndex||A valid ModelReferenceList index which this Model describes.|
|14-17||UInt32||Unknown1||Unknown Purpose. Ranges from 0-240.|
|18||UInt8||Unknown2||Unknown Purpose. Ranges from 0-108.|
|19-22||Int32||ActionOffset||Offset from the beginning of the Dungeon Block Record to an ActionRecord, which contains additional information about how this object behaves. Negative values indicate no such ActionRecord exists for this object.|
These values presumably control the color, intensity, and possibly range of the emitted light.
|0-1||Texture||Texture||The texture to use for the flat/NPC.|
|2-3||Gender||Gender||The gender of the flat/NPC. See Gender enumeration below.|
|4-5||UInt16||FactionId||The faction of the flat/NPC. For vaild FactionIDs see here.|
|6-10||UInt8[ 5 ]||Unknown||Unknown Purpose.|
Models may reference an Action structure via their ActionOffset field. The target object (and the target object of its action, etc.) is activated simultaneously with the source object. In this way targets can be chained together for several simultaneous effects.
|0-4||UInt8[ 5 ]||Data||See ActionData structure below.|
|5-8||Int32||TargetOffset||The offset from the beginning of the RDB file to the Object structure describing this action's target, or a negative value if there is no target.|
|9||ActionType||Type||Affects how the Data field is interpreted. See enumeration below.|
|0x09||Translation with Rotation|
|0x0e||Teleport to the linked flat|
|0x1e||Appears to be general "activate/use".|
Rotation and Translation actions format the Action.Data field in this way:
|0||Axis||Axis||The specific axis about which the object should rotate. Values range from 1 to 99, but see Axis enumeration below for most common values.|
|1-2||UInt16||Duration||Determines how long the object takes to reach its destination.|
|3-4||UInt16||Magnitude||The amount to move along/around the specified axis.|
Rotations rotate about the Axis while translations move along them.
Doors do not appear to use the Action Record. It is not known whether teleporting walls use it. Switches, levers, and moving platforms appear to use it.
For example, in Privateer's Hold there is a switch next to a platform with a throne on it. Flipping the switch invokes the switch's action, which rotates it into the flipped position. That action targets the platform, which makes it rise. The platform's action targets the throne, which also rises. All these are performed simultaneously.