The Open Data Description Language ( OpenDDL ) is a generic text-based language that is designed to store arbitrary data in a concise human-readable format. It can be used as a means for easily exchanging information among many programs or simply as a method for storing a program's data in an editable format.
8-499: The exact syntax of OpenDDL is described on the website openddl.org as well as in an appendix of the Open Game Engine Exchange Specification . An OpenDDL file is composed of a sequence of structures that can be either user-defined types or built-in primitive data types. The declaration of a structure consists of an identifier followed by an optional name, an optional property list, and finally,
16-462: A complete OpenGEX file describing a green cube is shown in the listing below. It begins with a group of Metric structures that define the units of measurement and the global up direction. Those are followed by a single GeometryNode structure that provides the name and transform for the cube. The geometric data for the cube is stored in the GeometryObject structure that is referenced by
24-744: A method for arbitrary data storage that maintains human readability. The OpenGEX file format is registered with the Internet Assigned Numbers Authority (IANA) as the model/vnd.opengex media type. The OpenGEX format is defined by the Open Game Engine Exchange Specification , which is available on the official website opengex.org . Export plugins that write the OpenGEX format are available for Autodesk Maya and 3D Studio Max , with an unofficial plugin available for Blender . At
32-437: The file) or local (unique within the enclosing structure). A global name consists of a dollar sign followed by an identifier, and a local name consists of a percent sign followed by a dollar sign. The Point structure above could be given the global name "position" as follows. Another structure could then include a reference to this point by using the ref data type: OpenDDL defines the 15 primitive data types described in
40-441: The following table. Each type has a long name and a short name. Additionally, the floating-point types each have alternate long and short names. Open Game Engine Exchange The Open Game Engine Exchange ( OpenGEX ) is a format that aids the application-agnostic transferring of complex scene data between 3D graphics apps including game engines and 3D modelling apps. It uses Open Data Description Language for data storage,
48-467: The geometry node. The geometry object structure contains a single mesh of triangle primitives that includes per-vertex positions, normals, and texture coordinates . Finally, the Material structure at the end of the file contains the green diffuse reflection color. The development of the OpenGEX format was funded by a crowd-sourcing campaign that ended on May 8, 2013. As the format was being designed,
56-458: The most basic level, an OpenGEX file consists of a node hierarchy, a set of objects, a set of materials, and some additional information about global units and axis orientation. The various node, object, and material structures contain all of the details such as geometric data and animation tracks within a hierarchy of additional types of structures defined by OpenGEX. The following types of data can appear in an OpenGEX file: A very simple example of
64-429: The structure's contents enclosed in braces. Raw data is always contained within structures whose identifiers are one of the data types described in the next section. For example, one may define a Point structure that holds the floating-point coordinates of a three-dimensional point as follows. Structures can have names that allow them to be referenced from other parts of the file. Names can be global (unique throughout
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