Daggerfall Mod:BLOCKS.BSA/Dungeon Block Records

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". E.g., "N0000019.RDB". These files are referenced in the dungeon records of MAPS.BSA.

General Format

Dungeon Block Record coarse structure

RdbHeader
ModelReferenceList
ModelDataList
ObjectSection

RdbHeader

Each Dungeon Block Record begins with a 20 byte long Header structure.

Offset	Type	Name	Description
0-3	UInt32	Unknown1	Unknown Purpose.
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.
16-19	UInt32	Unknown2	Unknown Purpose.

ModelReferenceList

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.

ModelReference structure

Offset	Type	Name	Description
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.

ModelDataList

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.

ObjectSection

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.

ObjectSection coarse structure

ObjectHeader
ObjectRootList
ObjectList

ObjectHeader

ObjectHeader structure

Offset	Type	Name	Description
0-3	UInt32	UnknownOffset	An offset from the beginning of the RDB file to a linked list of unknown purpose and format.
4-7	UInt32	Unknown1	Unknown Purpose.
8-11	UInt32	Unknown2	Unknown Purpose.
12-15	UInt32	Unknown3	Unknown Purpose.
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

ObjectRootList

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.

ObjectList

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.

Object structure

Offset	Type	Name	Description
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.

ObjectType

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.

ObjectType enumeration

Value	Name	Function
0x01	Model	A 3D model
0x02	LightSource	A light source
0x03	Flat	A Flat (including markers, junk, and monsters)

Type-Specific Structures

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.

Model

Model structure

Offset	Type	Name	Description
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	TriggerFlag_StartingLock	Sets the door's lock level and Trigger flag in a range from 0-240. 0 means no lock. 240 means magically locked and can only be unlocked by an Action.
18	UInt8	SoundIndex	ID of sound to play when action is executed. Also used for spell and text index.
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.

LightSource

LightSource structure

Offset	Type	Name	Description
0-3	UInt32	Unknown1	Unknown Purpose.
4-7	UInt32	Unknown2	Unknown Purpose.
8-9	UInt16	Unknown3	Unknown Purpose.

These values presumably control the color, intensity, and possibly range of the emitted light.

Flat

Flat structure

Offset	Type	Name	Description
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.

Gender enumeration

Value	Function
0x1200	Male
0x3200	Female

ActionList

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.

Action structure

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.

ActionType

Observed ActionType values

Value	Function
0x00	None
0x01	Translation
0x02	Unknown Purpose
0x04	Unknown Purpose
0x08	Rotation
0x09	Translation with Rotation
0x0b	Unknown Purpose
0x0c	Unknown Purpose
0x0e	Teleport to the linked flat
0x10	Unknown Purpose
0x11	Unknown Purpose
0x12	Unknown Purpose
0x14	Unknown Purpose
0x15	Unknown Purpose
0x16	Unknown Purpose
0x17	Unknown Purpose
0x18	Unknown Purpose
0x19	Unknown Purpose
0x1c	Unknown Purpose
0x1e	Appears to be general "activate/use".
0x1f	Unknown Purpose
0x20	Unknown Purpose
0x32	Unknown Purpose
0x63	Unknown Purpose
0x64	Unknown Purpose

ActionData

Rotation and Translation actions format the Action.Data field in this way:

ActionData structure

Offset	Type	Name	Description
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.

Axis

Axis enumeration

Value	Function
0x01	Negative X
0x02	Positive X
0x03	Negative Y
0x04	Positive Y
0x05	Negative Z
0x06	Positive Z

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.