SDK » Adding Aircraft
All aircraft are configured through the acdef.xml file. This file contains all the necessary data for proper aircraft function with 3wirex. All the aircraft you intend to use with 3wirex should have an associated model. If there is no model defined for a particular aircraft then 3wirex will not work when that aircraft is the active aircraft.
The acdef.xml file contains information about the aircraft models. This information includes catapult and arresting data, hook position data and the linked aircraft. Linked aircraft are the actual aircraft models that will use the data for each model entry.
| Element | Units | Comment |
| model | - | Container tag. Each aircraft model must have one. All the other tags need to be enclosed by these tags. |
| title | - | The name of the model. Usually the aircraft name. |
| catholdforce | - | This is the amount of holdback force applied. |
| catforce | - | This is the catapult launch force. |
| arrestforce | - | The arresting wire force applied on wire engagement. |
| offsets | - | This tag contains any offset data tags. |
| hookend | - | This tag contains the offsets of the location of the free end of the hook. |
| x | feet | The x-axis offset from the aircraft datum. |
| y | feet | The y-axis offset from the aircraft datum. |
| z | feet | The z-axis offset from the aircraft datum. |
| linkedaircraft | - | This section contains the FSX aircraft models that should use this model definition. |
| aircraft | - | This is the FSX title of the aircraft to be linked to the current model. It must be exactly the same as the title field of the aircraft in the aircraft.cfg file. |
| <model> <title>T-45 Goshawk</title> <catholdforce>34</catholdforce> <catforce>350</catforce> <arrestforce>220</arrestforce> <offsets> <hookend x="-14.5" y="0.0" z="-5.3" /> </offsets> <linkedaircraft> <aircraft>BAe Hawk T-45C Clean</aircraft> <aircraft>BAe Hawk T-45C BDU-33</aircraft> <aircraft>BAe Hawk T-45C Clean (USMC)</aircraft> <aircraft>BAe Hawk T-45C BDU-33 (USMC)</aircraft> <aircraft>BAe Hawk T-45C Blue Angels</aircraft> </linkedaircraft> </model> |
Example acdef.xml file
Adding a new aircraft only has to be done once per visual model. Once you have defined a model, any variants (i.e., repaints) that use this model are simply linked to it. To define a new aircraft follow the steps outlined below.
1. Copy an existing model entry
To start, simply copy and paste an existing definition into the acdef.xml file.
2. Modify title and linked aircraft
Modify the title and linked aircraft fields to suit the aircraft being defined. Ensure that all the linked aircraft names are exactly the same as the titles listed in the aircraft.cfg file.
3. Estimate forces
For most aircraft the forces will be fairly similar, however if you are using a much smaller or larger aircraft these values should be adjusted. The estimates made in this step will likely need adjusting after testing to get them right.
4. Locate the hook offset
This piece of information is vital to creating a working definition. This offset represents the location of the end of the hook. This is used to calculate when the aircraft engages a wire. The easiest way to find this information, if the source model is not available, is to use a light effect to find the correct position. In the aircraft.cfg file of the model to be defined, add a light to the [lights] section by copying and pasting the following line:
light.N = 3, X, Y, Z, fx_navred ,
replace N with the next number in the sequence of lights, and the values X, Y and Z with a guess at the location of the hook. Load up a flight in FSX using the aircraft model, turn on the lights and lower the hook. Through trial and error, edit the X, Y and Z coordinates of the light so that it is positioned on the end of the hook (map a key to the Aircraft (Reload) event to update the light position in FSX). The X, Y and Z coordinates can then be copied directly into the 3wirex model definition.
5. Test and refine
Take the aircraft for a test flight and see if you can snag the wire. Ensure that you get the “aircraft model data loaded” message after changing aircraft, this confirms that the model has loaded correctly.
6. Add it to the Definition Library
Once you have a working definition don't forget to send it to us so that we can share it with other sim pilots in the definition library.