CNOD (Cartography Node)

These objects appear to contain terrain data at various levels of detail.

The names of these objects are of the form cterrllxxxxyyyy where

• cterr is the literal cterr
• ll is the level of detail (power-of-two units on a side) of the terrain block
• xxxx is the x coordinate offset of the terrain block
• yyyy is the y coordinate offset of the terrain block

Each node contains a HEAD chunk, a VERT vertex list, a DDIF chunk, a DNRM chunk, a MGRP chunk, a MVTX chunk and a MIND chunk.

HEAD

Offset	Size	Type	Meaning
0x0000	4	int	???
0x0004	4	float	???
0x0008	4	float	???
0x000C	16	???	???
0x0010	4	???	???
0x0014	4	float	???

VERT

This is a 33x33 grid of 4-byte items. Each item appears to be 4 signed 8-bit values.

DDIF

This appears to be a 64x64 grid of 8-byte items. I don't know what the data represents.

DNRM

This appears to be a 128x128 grid of bytes, with each byte representing the 4-bit x and y components of the normal. 0x88 would be a vertical normal.

MGRP

MVTX

This is a variable length array of 6-byte items. It is only present in the highest LOD (6).

Offset	Size	Type	Meaning
0x0000	2	short	Appears to be an index, possibly into the VERT array
0x0002	1	byte	Unknown - this and the 3 below add to 0xFF, 0xFE, 0xFD or 0xFC for 1, 2, 3 or 4 non-zero values respectively
0x0003	1	byte	???
0x0004	1	byte	???
0x0005	1	byte	???

MIND

This appears to be an array of 2048 triangles (two for each square on a 32x32 grid), each consisting of 3 short indexes into the MVTX array. It is only present in the highest LOD (6).