World
Wide Guide | Knowledge Bank |
Kukushkin's Notebook | Basics
of Simulation
World
Wide Guide | Knowledge Bank |
Kukushkin's Notebook | Basics
of Simulation
Locations and priorities of all scenery files used
by FS5.1 are stored in the scenery library. The scenery library also contains
pointers to CD-ROM performance boosters and some additional info. FS5 uses
the scenery library in order to select BGL files to be used. As you fly,
it periodically checks all files/directories from the scenery library.
Each scenery file begins with a header which contains boundaries for the area covered by that file. FS5 uses a scenery file only if the aircraft is within the boundaries defined in the header. Later, when FS5 interprets contents of scenery files, additional visibility checks are made in order to determine which parts of the scenery or objects should be visible/available. However, FS5 never interprets contents of scenery files rejected because of the aircraft being outside of their boundaries defined in headers. In particular, objects from such files are never visible even if they should be because of their dimensions, and navaids are not available even if they should be because of their ranges. For this reason, most BGL headers define boundaries that include a certain area not covered by the scenery, but where the scenery should still be visible and navaids still available.
Scenery files in the scenery library are organized into layers. Each layer contains a path (wildcards allowed) to one or more scenery files, and some options.
There are two special layers in the scenery library: FS5 Default World and FS5 Default World - Metro. You cannot change or remove these layers, but you can change their priorities. FS5 Default World contains the default (lowest-resolution) synth scenery of FS5. It points to the WORLD subdirectory of the main SCENERY directory. Because it contains only synth scenery, it should normally have the lowest priority.
FS5 Default World - Metro contains the default 7 scenery areas and many auxiliary scenery files used by FS5 (magnetic variation, World/Airports menu, time zones, etc.). It points to the main SCENERY directory. Lazy users also install downloaded scenery there. The order of layers determines priorities of scenery files. FS5 follows this order while processing different sections of scenery files (navaids; synth scenery; visual scenery etc).
A special kind of scenery file is an exclusion file. An exclusion file instructs FS5 to ignore visual scenery objects and some navaids that are defined in layers below the layer where the exclusion file resides and located within the area defined in the exclusion file. Exclusion files affect visual scenery, VORs, NDBs and ATIS messages. They do not affect synth scenery, dynamic scenery and data structures from section 16, including location markers and elevated surfaces. Exclusion files are normally used to resolve scenery conflicts such as duplicate objects or navaids.
The settings in the scenery library affect only priorities (that is, drawing order) among objects of the same kind. For example, drawing order of ground polygons can be influenced, but the visual scenery is always drawn above the synth scenery, regardless of priorities set in the scenery library, See "How FS5 displays scenery" for more information about priorities.
Information for the scenery library is stored in the file WORLD.VIS in the main SCENERY directory of FS5. You can modify it using the Scenery/Scenery Library dialog box. FS5.1 contains a bug that can cause WORLD.VIS to be wiped out after you change it. So you should always back up this file before making any changes.
Procedures for manipulating the scenery library are well-described in the FS5 manual. I only want to add a few interesting observations. Priorities of layers are determined by layer numbers. Priority of the synth scenery decreases with increasing layer number. Unlike that, priority of the visual scenery increases with increasing layer number. However, because scenery conflicts caused by the visual scenery or navaids are normally resolved using exclusion files, which affect only bigger layer numbers, layers with lower numbers are normally said to have higher priority.
According to my observations, the layer type does not affect any priorities and is used only by the Auto Arrange button. This button sorts layers according to the layer type.
Scenery files referenced in layers must be stored using a special directory structure. The directory where a scenery is to be stored must have two subdirectories, SCENERY and TEXTURE (not TEXTURES!). All scenery [*.BGL] files must be put into the SCENERY subdirectory. All texture [*.R8], palette [*.PAL] and haze [*.HAZ] files must be put into the TEXTURE subdirectory. When adding the scenery to the scenery library, the path to files in the SCENERY subdirectory must be specified. FS5 will NOT allow adding sceneries with the deepest subdirectory name other than SCENERY. Similarly, the Search for Scenery Files command does not scan any directories not ending with '\SCENERY'. Paths in WORLD.VIS are stored without this last 'SCENERY' subdirectory.
One exception from the above rules are texture files named SEED??.R8. They must always be put into the main TEXTURE directory of FS5. The reason is, these texture files are used by the synth scenery. Because the surrounding synth scenery is buffered in an array before being drawn, no information about texture file locations is available at drawing time.