Grass.extm

grass.extm files describe the height and color of the main field grass and add-on content field.

Generated grass height map of Hyrule Main Field

Full RGB color spectrum used for grass.

grass.extm File Specification

grass.extm File Layout

Each file contains a 64×64 grid. For each vertex there is 4 bytes of data that describe the height of the grass and color.

Grass Map Data

Each entry in the grass data table is 4 bytes long. The rgb values are capable of producing all colors.

Offset (h)	Size	Data Type	Description
0x00	1	Unsigned Byte	Blade height
0x01	1	Unsigned Byte	r, red
0x02	1	Unsigned Byte	g, green
0x03	1	Unsigned Byte	b, blue

x and z can be calculated, while iterating through the data table:

for (int index = 0; index < 256 * 256; index++) {
    uint x = index % 256;
    uint z = index / 256;
}

Material Index

id	file	name	group	attribute	attribute_sub	flag	name (en)	group (en)
0	Blade_Green	草		A	None	0	Grass
1	Blade_Yellow	草		B	None	0	Grass
0	WoodChip_00	木くず00	木くず	None	None	0	Wood Chips 00	Wood Chips
1	WoodChip_01	木くず01	木くず	None	None	0	Wood Chips 01	Wood Chips
2	WoodChip_02	木くず02	木くず	None	None	0	Wood Chips 02	Wood Chips
3	WoodChip_03	木くず03	木くず	None	None	0	Wood Chips 03	Wood Chips
4	WoodChip_04	木くず04葦	木くず	None	None	0	Wood Chips 04 Reeds	Wood Chips
5	WoodChip_05	木くず04葦	木くず	None	None	0	Wood Chips 05 Leaves	Wood Chips