Item Placement

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Item Placement

IPL Sections: 2DFX • AUZO • BLOK • CARS • CULL • ENEX • GRGE INST • JUMP • LINK • LODM • MLO+ • MULT • OCCL PATH • PICK • RTFX • SLOW • TCYC • VNOD • ZONE

Item placement files, usually identicated by the file extension .ipl, are a parts of the map system and used to create and place (for example) different objects, zones of special behaviour or paths in the world. All games do support standart item placement files which are stored in plain text format and can be opened and edited using any text-editing program (like Notepad). Also there are tools to simplify the placement of different aspects of the IPL files. San Andreas as the first game also introduced an binary format for item placement files and with GTA IV most of the placement information is stored inside of binary files (for more information see WPL).

Overview

The structure and format of the item placement file is similar to the format of the item definition files.

Format and syntax description

Just like definitions placement information files are split up into sections. Each section is inicated by an identifier specifying the way the section gets parsed by the game. The sections themselves are filled with the entries containing the placement informations. Each must be placed on an seperate line. However lines can also be commented out (by starting them with the character '#') or left entry. If so the games parser simply ignores them which means they got skipped and do not get an index inside the internal placement array. This is important for different things, like the San Andreas LOD system. Each section gets terminated by the string "end". Both (identifying and terminating strings) are case insensitive, but they are stored in lower case by default.

Comments can also be placed outside sections. Just like empty lines there they will also get ignored. It is also possible to add an comment to the end of an line but breaking the line format rule of the current section using comments may cause hard to find game crashes. It is recommended to put an comment on a seperate line.

Lines itself are allways formatted in the same way differing only in the number of their parameters descriping the semantical content of the line. Those parameters are comma-seperated using the ',' character. Whitespace characters at the beginning or the end of an parameter get trimmed but they are usually used to give the content a more clear structure to make it more easier to read for human. Strings can be encased by the character '"', but this is optional and rarely used by default. Also the games parser uses an invariant culture to parse numerical values and strings. Which means strings are ASCII encrypted and the decimal seperator is '.'.

Section example

inst
...
end

Binary format

San Andreas introduced an simple binary format of item placement files. They are stored as "streaming files" inside the archive files. Editing them requires an special editor (see below). The format is pretty simple and their possibilities are not completely used by Rockstar. By default they do only support INST and CARS sections. It is unconfirmed if other sections also can be used or if they are just stubs which are not implemented. Anyway their binary format is completely unknown.

This section is incomplete. You can help by fixing and expanding it.

Header

Each binary placement information file starts with an 4-Byte identifier followed by a header containing information about the files content.

4b  - CHAR[4]   - Always "bnry"
4b  - INT32     - Number of item instances
4b  - INT32     - Number of unknown 1 (CULL ?)
4b  - INT32     - Number of unknown 2 (GRGE ?)
4b  - INT32     - Number of unknown 3 (ENEX ?)
4b  - INT32     - Number of parked cars
4b  - INT32     - Number of unknown 4 (PICK ?)
4b  - INT32     - Offset of item instances (0x4C by default)
4b  - INT32     - Size of item instances (unused - always 0)
4b  - INT32     - Offset of unknown 1
4b  - INT32     - Size of unknown 1 (unused - always 0)
4b  - INT32     - Offset of unknown 2
4b  - INT32     - Size of unknown 2 (unused - always 0)
4b  - INT32     - Offset of unknown 3
4b  - INT32     - Size of unknown 3 (unused - always 0)
4b  - INT32     - Offset of parked cars
4b  - INT32     - Size of parked cars (unused - always 0)
4b  - INT32     - Offset of unknown 4
4b  - INT32     - Size of unknown 4 (unused - always 0)

The header is followed by the arrays of the entries. For more information about their format see the articles about the sections.

Sections

The following table contains basic information about all known sections. For additional information read the articles itself.

Identifier	Supported games	Description
INST		Most important section: places objects defined in OBJS, TOBJ, ANIM or TANM in the world.
CULL		Creates zones with special behaviour and influences to e.g. NPC's or weather.
PATH		Creates waypoints for random NPC spawns. Note: this section is also present in San Andreas and GTA IV. It is used as a base for Rockstar's paths compiler, but gets ignored by the games. For more information see: Paths.
GRGE		Creates zones for ingame garages.
ENEX		Creates entrace and exit markers.
PICK		Creates weapon pickups.
JUMP		Creates unique stunt jumps.
TCYC		Apparently custom weather.
AUZO		Creates zones playing an audio stream if the user enters it.
MULT		–
CARS		Creates parked car spawns
OCCL		Creates occlusion zones for seperated rendering.
ZONE, MZON		Creates ingame regions. MZON is only used for GTA IV and contains one type of zones.
BLOK		Apparently ignored by the game – appears to be used to allocate responsibilities during the development stage of GTA IV, but also could be used to place decision markers.
VNOD		Extented format of PATH – apparently only used for multiplayer mode.
LINK		–
MLO+		Unknown – apparently used to create instances of MLO definitions.
RTFX		–
LODM		–
SLOW		–
2DFX		Creates particle effects in the world.

Tools

• KEd – By JernejL
• MEd – By Tonywob
•  GTAForums: IPL Helper – By Xmen
• Binary (De-)Compiler – By ocram88

See also

• Item definition
• Map System
• WPL – Major GTA IV item placement file.

External Links

•  GTAForums: GTA3/VC Map File Documentation and Troubleshooting - Topic by Opius covering general features of IPL files in GTA3 and GTA VC.
•  GTAForums: Paths Documentation for SA, VC and GTA3 - Topic by REspawn detailing Vice City's paths
•  GTAForums: GTA SA IPL Documentation - Topic by spaceeinstein covering details of the IPL format in GTA SA.
•  GTAForums: Enex Documentation - Topic by OrionSR
•  GTAForums: Explanation of GTA SA LOD System - Post by steve-m explaining the LOD system for IPL files in GTA SA.
• Explanation of the path-section in a VC IPL - by Cerbera