AGN (FSX)

Applicable
MS Flight
FSXA
FSX
FS2004
FS2002

This document describes the FSX format for autogen (AGN) files. This description is not yet complete, so feel free to add more information if you have any.

Sections

The AGN file uses the RIFF format, this means that the file consists of different sections. Each section starts with a four character label, followed by the size of the content in bytes (this size is thus without the length of the header itself).

The main RIFF section itself has one additional parameter, this is a four character string that indicates the type of RIFF AGN file. For an FSX AGN file the value should always be AGNX.

The following subsection show more details about the content of these different sections.

VERS

Contains versions information about the AGN file.

 int version (normally 4)
 int version (normally 13107)

GBDD

Contains information about autogen generic buildings

 int percentage of 1 and 2 floor buildings (normally 10)
 int percentage of 3 to 5 floor buildings (normally 10)
 int percentage of 6 to 8 floor buildings (normally 10)
 int percentage of 9 to 12 floor buildings (normally 10)

Valid values for percentage are from 0x00 (0%) to 0x14 (100%).

GBLD

Contains building information.

GBLR

Contains information about Generic Buildings.

 GUID roof type (will use default roofs, if 0)

For each Generic Building:

 float X position of first point 
 float Y position of first point
 float X vector to the second point
 float Y vector to the second point
 float X position of third point
 float Y position of third point 

Repeat GBLR sections for each GUID used.

PREG

For vegatation information

PRDE

For vegatation polygon. Contains:

 GUID vegatation type

For each polygon:

 int number of vertices

For each vertex:

 single x
 single y

The x and y coordinates are given as offset in the LOD13 square (range 0 till 1).

VGRG

Contains information about pre-FSX style rectangular vegetation regions.

VGRE

 GUID vegetation type

For each rectangle:

 float X position of first point
 float Y position of first point
 float X position of second point
 float Y position of second point