3DN

3DN is a slightly simplified version of the 3DF and CAR file formats from the Action Forms-developed Carnivores games, used in Carnivores: Dinosaur Hunter. Specifically, the 3DN files swap the order of faces and vertices, so that vertices are stored first, and the files store only the model; the texture, animations, and sounds are stored elsewhere. These files are located in \models.

Format[]

// for each vertex (16 bytes)

float

4

X coordinate

float

4

Y coordinate

float

4

Z coordinate

int32

4

owner

bone to which vertex is attached, or -1 if none

// for each face (52 bytes)

uint32

4

v1

vertex 1

uint32

4

v2

vertex 2

uint32

4

v3

vertex 3

int16

2

tax

v1 texture U coordinate

int16

2

tay

v1 texture V coordinate

int16

2

tbx

v2 texture U coordinate

int16

2

tby

v2 texture V coordinate

int16

2

tcx

v3 texture U coordinate

int16

2

tcy

v3 texture V coordinate

uint16

2

flags

always null?

uint16

2

DMask

appears to be unused by the games, possibly editor/tool-specific

uint32

4

Distant

index to previous (parent) face

uint32

4

Next

index to next (child) face

uint32

4

group

appears to be unused by the games, possibly editor/tool-specific

uint32

4

reserv[0]

0x00

unused; reserved for future use

uint32

4

reserv[1]

0x00

unused; reserved for future use

uint32

4

reserv[2]

0x00

unused; reserved for future use

// for each bone (48 bytes)

char

32

name

float

4

X coordinate

float

4

Y coordinate

float

4

Z coordinate

int16

2

index to the parent bone, -1 if there is no parent

uint16

2

whether the bone is hidden in Designer 2; has no effect in-game

Notes[]

The owner field in the vertex block is treated as a int32 by the mobile games, instead of two separate uint16 fields as the PC games and editors did. There are no models with any non-null values in the second field, and no plans for editors to export to 3DN, so this is not a problem.
The texture UV coordinates were reordered from UUUVVV to UVUVUV (pairs of UV) by Tatem because the latter ordering is more convenient for modern hardware to handle. However, unlike typical modern implementations, which use normalized scalar values, 3DN files (and their CAR and 3DF predecessors) use pixel values for these fields.