X-Plane Scenery Files Notes and Info
Note: this document was originally and posted written 12/25/02 and reflects
the X-Plane version 7 scenery system. It is provided here for completeness.
This page contains various random info and notes for scenery authors.
Naming Conventions for ENV files and folders.
Scenery files (.env) files are named after the latitude (north-south position)
and longitude (east-west position) of their southwest corner. Each
.env file covers a 1x1 degree "square" of the Earth (or Mars). The
first number in the .env file name is the latitude, the second the longitude.
Positive latitudes are north of the equator, negative are south. Positive
longitudes are east of the prime meridien, negative are west. Latitudes
and longitudes of zero are given a plus sign. Every file name must
have a plus or minus sign for the latitude and longitude and use two digits
for the latitude and three for the longitude. Some examples:
|72 degrees west
|71 degrees west
|43 degrees north
|42 degrees north
|10 degrees east
|11 degrees east
|51 degrees north
|50 degrees north
|12 degrees west
|11 degrees west
|39 degrees south
|40 degrees south
|1 degree west
|0 degrees east (prime meridien)
|1 degree north
|0 degrees north (the equator)
Remember that if you are in the western hemisphere, the longitude of the
file will be larger
than the point you are interested in. For
example, the point 42.30 north, -71.50 west is in the file +42-072, not +42-071.
The same applies to latitude in the southern hemisphere.
The Earth nav data folder is subdivided with a single folder for each 10x10
degree square of the earth. These folders are always aligned to a multipel
of ten degrees. Just like the .env files above, the folder is named
for the southwest most file that woudl live in the folder. Some examples:
Again, when in the western hemisphere the folder name will be larger
than the .env file. For example, the file +42-072 is in the folder
+40-080, not +40-070.
X-Plane and WorldMaker will fill in pure water (ocean) for a missing .env
file. So by convention .env files that contain only water are simply
omitted to save disk space. If a subfolder does not contain any .env
files, it may be omitted as well. This is normal for a distribution
About Custom Scenery Packages
Starting with X-Plane version 6.50 scenery can be 'packaged' as a single
folder of folders and files. This folder is dragged directly into the
Custom Scenery folder; there is no need to move various files to various
random locations. This offers a big improvement in installation.
Custom Scenery Structure
The custom scenery folder contains a single folder for each package. Each
package in turn contains zero or more of the four following folders:
- Earth nav data
- Custom Objects
- Custom Object Textures
- Custom Terrain Textures
These folders correspond to the folders in the old resources folder. The
Earth nav data folder should contain subfolders for the 10x10 degree areas
of scenery you cover, with individual .env files inside the subfolders.
Texture, terrain and object paths are resolved relative to these 'Custom'
folders in your scenery package. If you have an object that has a texture
path of 'taxiways:signs.bmp', then you must place the signs.bmp file inside
a folder called 'taxiways' inside the Custom Object Textures folder. In
essense the scenery package is your own mini-resources folder.
You can still have arbitrary subfolders for bitmaps and objects inside the
'Custom' folders, but since your scenery package is entirely isolated from
all other scenery packages, there is no longer a risk of naming conflicts
Custom Scenery Load Order
Custom scenery is loaded in alphabetical order by the name of the package's
folder. Where the same .env file or airport is specified in multiple
packages, the alphabetically first one takes priority. All custom scenery
takes priority over scenery installed in the 'resources' folder.
What Can Be Overriden and Edited
You can include custom objects, their textures, custom terrain textures,
.env files, and an apt.dat file in a custom scenery package. The apt.dat
file is merged into the X-Plane world by replacing any airport that occurs
in your apt.dat with your data, wholy overriding the default navigation database.
.env files entirely override preexisting .env files on a 1x1 degree
basis. Custom object and terrain textures and custom objects are only
used when referred to by your .env files. If another package refers
to objects of the same name, it will not see your objects even if it does
not provide them itself.
When editing in WorldMaker, WorldMaker will edit the .env files from the
scenery package that contains them and is first in the alphabetical list.
WorldMaker will not (as of this writing - X-Plane 650) edit the apt.dat
files in a custom scenery package; to edit them you must edit the main apt.dat
fiel and then copy the airport information into your scenery packages apt.dat
file using a text editor.
About Custom Objects
Maximizing Performance with Custom Objects
The single biggest factor for custom objects is the sharing of textures.
X-Plane can render a lot of custom objects that share the same texture,
but using multiple textures slows things down. It is better to use
one bigger texture than multiple smaller ones. Since X-Plane 640, the
sim only uses type-II objects (objects with one texture).
'Solid' quads (code 5) are slower than normal quads (code 4) because X-Plane
must do collision detection to determine whether the aircraft can land on
It is faster to draw a single bigger object than many smallers ones, but
if an object is so big that most of it is off screen it is faster to break
it into pieces so that the ones that are off screen don't have to be drawn.
Consider breaking into pieces objects that become larger than one .env
quad (533 meters). For an airport, consider making each terminal its
Bugs with Placement of Custom Objects
Currently custom objects are rotated according to the current Z axis and
not relative to true north. As a result, as the OpenGL coordinate system
shifts in X-Plane, objects may rotate ever so slightly due to round world
problems. Given a long enough object (like a terminal), its ends will
rotate as the user flies through the area, possibly altering their position
relative to other objects.
Currently custom objects face up along the current Y axis, rather than straight
up from the earth. The point 0,0,0 on the object is placed on the earth's
surface. If the Y axis and up are misaligned enough (which happens
at the edge of loaded scenery), the object may 'hang off the earth' into
space a little bit. This may be evident through phenomena like being
able to see under buildings.
Hopefully both of these bugs will be addressed in a future X-Plane release.