OAR Format 0.1

Technical Reference -> Terms -> OAR format 0.1

Detail

At the present time, a region archive is a gzipped tar file (tar.gz) in the the original unix tar format (not USTAR). This can be extracted and created with standard tools (7-zip on Windows). The structure of the archive is as follows

archive.xml
assets/
objects/
terrains/

archive.xml

This is the archive control file. At the moment it contains only a major and minor version number, to allow compatibility with future format changes.

assets/

This directory contains all the assets in the archive. Each filename has the following format

uuid_asset type.asset extension

The uuid section must always be present and form a valid uuid - it is used directly as the uuid for that asset. The asset type and asset extension are used to identify the type of asset and the asset extension allows the asset to be associated with different editors on platforms such as Windows. For instance, a script will always have the asset type and extension script.lsl. A full list of asset types and extensions can be found in the file

OpenSim/Region/Environment/Modules/World/Archiver/ArchiveConstants.cs

in the OpenSim distribution.

objects/

Each individual file in here is an object in the region (where an object [linkset] can be composed of many prims). The file format used is OpenSim's XML2 format. Each filename has the following structure by default

Object name_x-y-z__uuid.xml

Unlike asset filenames, any component of this name can be changed without affecting any attributes of the object itself - this information is taken from the xml instead. Indeed, this file can have any name - there is no need for any of the sections to be present. An example object file name is

Primitive_154-121-062__9be68fdd-f740-4a0f-9675-dfbbb536b946.xml

terrains/

This contains the terrain file for the region, stored in RAW format. The filename must end with .r32. For example,

OpenSim Test.r32