INST

INST (IPL section)

Short description:	Used to place objects in the world
Supported games:
IPL Sections: 2DFX • AUZO • BLOK • CARS • CULL • ENEX • GRGE INST • JUMP • LINK • LODM • MLO+ • MULT • OCCL PATH • PICK • RTFX • SLOW • TCYC • VNOD • ZONE

INST is a section in the item placement file in GTA III, Vice City, San Andreas, and GTA IV. It is used to place static, dynamic, time controlled and animated objects in the world. It is supported by all major PC versions of the GTA 3D series but its format differs slightly between the games.

Format

GTA III and Vice City

inst
Id, ModelName, PosX, PosY, PosZ, ScaleX, ScaleY, ScaleZ, RotX, RotY, RotZ, RotW
end

	Identifier	Type	Description
A	Id	integer	A number which is used to identify the object as defined in the IDE file inside the map system.
B	ModelName	string	The name of the model inside an image file which is defined in the gta.dat file without extension (.dff)
C,D,E	PosX, PosY, PosZ	float[3]	The position of the object in the world as floating point values. Note: the decimal seperator must be ".", not ",".
F,G,H	ScaleX, ScaleY, ScaleZ	float[3]	The scaling of the object as floating point values. By default each value is 1.0, which means the object is not scaled at all. Note: the decimal seperator must be ".", not ",".
I,J,K,L	RotX, RotY, RotZ, RotW	float[4]	The rotation of the object as quarternion. Note: the decimal seperator must be ".", not ",".

Note that if this format is used in Vice City, the interior of the object defaults to 0.

Vice City

inst
Id, ModelName, Interior, PosX, PosY, PosZ, ScaleX, ScaleY, ScaleZ, RotX, RotY, RotZ, RotW
end

	Identifier	Type	Description
A	Id	integer	A number which is used to identify the object as defined in the IDE file inside the map system.
B	ModelName	string	The name of the model inside an image file which is defined in the gta.dat file without extension (.dff)
C	Interior	float	A number defining the interior (render-level) the object is located in.
D,E,F	PosX, PosY, PosZ	float[3]	The position of the object in the world as floating point values. Note: the decimal seperator must be ".", not ",".
G,H,I	ScaleX, ScaleY, ScaleZ	float[3]	The scaling of the object as floating point values. By default each value is 1.0, which means the object is not scaled at all. Note: the decimal seperator must be ".", not ",".
J,K,L,M	RotX, RotY, RotZ, RotW	float[4]	The rotation of the object as quarternion. Note: the decimal seperator must be ".", not ",".

San Andreas

inst
Id, ModelName, Flags/Interior, PosX, PosY, PosZ, RotX, RotY, RotZ, RotW, LOD
end

	Identifier	Type	Description
A	Id	integer	A number which is used to identify the object as defined in the IDE inside the map system.
B	ModelName	string	The name of the model inside an image file which is defined in the gta.dat file without extension (.dff). The parameter doesn't seem to function in the game. Any name used will not affect the rendering of the model.
C	Flags / Interior	integer	Flags for specific object instance. First byte is used for defining the interior (render-level) the object is located in.
D,E,F	PosX, PosY, PosZ	float[3]	The position of the object in the world as floating point values.
G,H,I,J	RotX, RotY, RotZ, RotW	float[4]	The rotation of the object as quarternion. Note: the decimal seperator must be ".", not ",".
K	LOD	integer	The number of the LOD which is located inside the same instance block as the current model. By default this is -1 which means no LOD is defined.[1]

Binary Format

INST is also one of the known sections which can be used in binary format inside streaming files. Its format is similar to the plain text format:

4b  - FLOAT    - Position X
4b  - FLOAT    - Position Y
4b  - FLOAT    - Position Z
4b  - FLOAT    - Rotation X
4b  - FLOAT    - Rotation Y
4b  - FLOAT    - Rotation Z
4b  - FLOAT    - Rotation W
4b  - INT32    - Object ID (as an index to the IDE)
4b  - INT32    - Flags / Interior (first byte used as interior (visible area))
4b  - INT32    - LOD index

Flags

San Andreas also includes flags in addition to the interior ID for INST lines. First byte is used for interior ID, so there is no flags for first bits.

Bits	Dec	Hex	Description	Examples
8	256	0x100	Unimportant	Mostly telegraph poles and other props
9	512	0x200	Force the use of matrix rotation, even if XY rotation is low	Props with XY rotation
10	1024	0x400	Underwater	Land masses, touching or bellow water
11	2048	0x800	Underground	Tunnels
12	4096	0x1000	Underground top	Tunnel entrances and roof

Limitations

Each game has different limitations. The most important limit for the instance section is the so-called map boundary, which is a notional boundary around the map. Outside those borders no objects will be visible. If an object is intersecting the bounds it may be displayed incorrectly.

Game	Mapping Boundary
	San Andreas has a square (or cube) as the major limit. Its dimension is 3000.0 units away from the origin point. This limit can be increased using the SA Limit Adjuster by Sacky

Related tools

•  GTAForums: IPL Helper - by Xmen
• Binary (De-)Compiler - By ocram88

See also

• Item placement file format specification
• SA Limit Adjuster – by Sacky

External links

• ^  GTAForums: Explanation of GTA SA LOD System - Post by steve-m explaining the LOD system for IPL files in GTA SA.
•  GTAForums: Documentation of San Andreas IPL file format
•  GTAForums: GTA III/Vice City mapping formats