PSDL - Parsed Scene Description LanguageEach city has one PSDL-file. This file defines roads, ground surface and buildings. In addition, the PSDL-file also provides an easy way to automatically place props along roads etc. This is particularly good for placing street lights, parking meters and similar objects. The geometry of a city is divided into blocks. A block is a small section of the city, similar to the regular definition of a city block. One difference, though, is that roads and intersections are also placed in their own blocks. The block structure is used for all kinds of things in the game. Most obvious are visible surface identification, collision detection, ambient "intelligence", etc. All of these are calculated with respect of the block structure. PSDL-MLAs an effort to facilitate development of PSDL editors and/or PSDL export filters for common 3D modeling tools, PSDL-ML has been developed. PSDL-ML is an XML-format used to describe the content of a PSDL file. Currently, PSDL-ML is not a 100% accurate one-to-one mapping to PSDL, istead it focuses on items that can be exported from general 3D modeling tools without too much work. The intention is that specific PSDL constraints are to be computed by a PSDL-ML to PSDL converter software. Currently only the PSDL Viewer, by fre_ber, can do this. But other, free-standing, program will hopefully be developed. PSDL-ML is still under development, currently not all block attributres are encodable in PSDL-ML, and some parameters of the already implemented block attributes are missing. Still, the current specification handles the most common attributes, and a pretty complete city can be expressed in PSDL-ML. |