water.extm
files describe the water heightmap and the texture of the main field and add-on content field.
File Locations | vol/content/Terrain/A/MainField/ |
Extension | .water.extm |
Parent Archive | .water.extm.sstera |
Endianness | Little Endian |
Each file contains a 64 × 64 grid. For each vertex there is 8 bytes of data that describe the height of the mesh, the material type and flow speed.
Each entry in the water data table is 8 bytes long.
struct waterData {
unsigned short height;
unsigned short xAxisFlowRate;
unsigned short zAxisFlowRate;
unsigned char unk00;
unsigned char materialIndex;
};
Offset | Length | Type | Description |
---|---|---|---|
0x00 |
2 | Unsigned Short | height (Vertex y component |
0x02 |
2 | Unsigned Short | xAxisFlowRate . |
0x04 |
2 | Unsigned Short | zAxisFlowRate . |
0x05 |
1 | Unsigned Byte | materialIndex + 3 . This may act as a checksum? |
0x06 |
1 | Unsigned Byte | materialIndex |
height
and flowSpeed
are stored as unsigned shorts, but seem to map to float values. These can be calculated by dividing by the max size of an unsigned short:
32767 / 0xffff = 0.5
height
is furthur multiplied by another constant to get the final height (the constant is unknown at this time).
x
and z
can be calculated, while iterating through the data table:
for (int index = 0; index < 64 * 64; index++) {
uint x = index % 64;
uint z = index / 64;
}
Note that z
is expected to be an integer quotient. The floor
function can be used if integer division is not supported.
Flow Rates are calculated as (flowRate * 2) - 1
and ranges from -1
to 1
. On the x-axis this changes flow direction from East (-1
) to West (+1
) and on the z-axis from North (-1
) to South (+1
).
id | file | name | attribute | attribute_sub | flag | Google Translated |
---|---|---|---|---|---|---|
0 | Water | 水 | Water | Water | 0 | Water |
1 | HotWater | 熱湯 | Water | Water_Hot | 0 | Hot water |
2 | Poison | 毒水 | Water | Water_Poison | 0 | Poison water |
3 | Lava | 溶岩 | Lava | Lava | 0 | Lava |
4 | IceWater | 冷たい水 | Water | Water_Ice | 0 | Cold water |
5 | Mud | 泥沼 | Bog | Bog | 0 | Bog |
6 | Clear01 | 透明水01 | Water | Water | 0 | Clear water 01 |
7 | Sea | 海 | Water | Water | 0 | Ocean |
This data is stored in Terrain.Tex1.bfres