Item Placement

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 identified by the file extension .ipl, are a part 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 support standard item placement files which are mostly stored in plain text format that can be opened and edited using any text-editing program (like Notepad), but there are tools to simplify editing. San Andreas is the first game to introduce a binary format for item placement files. Most of the placement information in GTA IV is stored inside of binary files (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 indicated by a section identifier specifying the way the section gets parsed by the game. The sections themselves are filled with the entries containing the placement information. Each entry must be placed on a separate line. This is important for line-dependent entries, like the San Andreas LOD system. The end of every section is indicated by the terminating string "end". Both (identifying and terminating strings) are not case sensitive, but by default they are written in lower case.

Comments are usually indicated by the character # (number sign). It is possible to add comments to the end of a line, but breaking the line format for the current section using comments may cause the game to crash during loading. It is recommended that a comment should be placed on a separate line. Comments can also be placed outside of sections.

Lines itself are always formatted in the same way differing only in the number of their parameters describing the semantical content of the line. Parameters are usually separated by the character , (comma). 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 " (quotation mark), 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 separator is . (period).

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 all known sections in the item placement.

Identifier	Supported games	Description
INST		Most important section: places objects defined in OBJS, TOBJ, ANIM or TANM in the world.
ZONE		Creates ingame regions.
CULL		Creates zones with special behaviour and influences to e.g. NPC's or weather.
PICK		Creates weapon pickups.
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.
OCCL		Creates occlusion zones for separated rendering.
MULT		–
GRGE		Creates zones for in-game garages.
ENEX		Creates entrance and exit markers.
CARS		Creates car generators.
JUMP		Creates unique stunt jumps.
TCYC		Creates timecycle modifiers.
AUZO		Creates zones playing an audio stream if the user enters it.
MZON		–
VNOD		Extended format of PATH – apparently only used for multiplayer mode.
LINK		–
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 makers.
MLO+		MLO placement – Used to place offsets for GTA IV's interiors. The interiors themselfes get placed inside the IDE file section MLO.
2DFX		Used to make many game effects, for example - Particle.
LODM		–
SLOW		Unknown for what it is responsible, used very rare and only in two extended .WPL. Section contains a box.

Tools

• KEd – By JernejL
• MEd – By Tonywob
•  GTAForums: IPL Helper – By Xmen
• Binary (De-)Compiler – By ocram88
•  GTAForums: SA Binary IPL Exporter for 3DS Max – by Gforce

See also

• Item definition
• 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: GTA SA IPL Documentation - Topic by spaceeinstein covering details of the IPL format in GTA SA.