WINCH AND PARACHUTE DEFINITIONS
On this page we describe both the Winch and Parachute sim objects, since currently the simulation only uses parachutes for the winch tow-cable, so they are very much linked.
The Winch
A Winch sim object will only use a limited number of parameters that the other Ground Vehicles use, specifically:
[VERSION]
[fltsim.N]
-title
,model
,texture
,ui_manufacturer
[General]
-category
("Winch")[contact_points]
-wheel_radius
,static_pitch
,static_cg_height
You will also need to set up a reference_points.cfg file, with numbered sections corresponding to the available drums on the winch. Each reference point you define is the point at which the winch cable for the drum will be attached.
Specific Animations
Currently the default winch models do not require any animations and are basically static models, meaning they don't need any specific model behaviour helpers either. This may change in future updates.
Sim.cfg
The sim.cfg
file of a Winch must contain the following section and parameter:
[WINCH]
Parameter | Description | Type | Required |
---|---|---|---|
drum_count |
The number of cable drums available to the winch. A value between 1 and 3. |
Integer |
Yes |
ai.cfg
You may optionally add an ai.cfg
file as part of the Winch sim object package. This file only requires the [VERSION]
section and the following section and parameters:
[WINCH]
Parameter | Description | Type | Required |
---|---|---|---|
launchHeading |
The angle of the winch relative to the heading of the runway in degrees. Default value is 0. |
Real | No |
parachuteTitle |
The title of the SimObject to use as a parachute. Default is "Parachute". |
String | No |
Note on SimVars
There are no specific "winch only" SimVars, however you can use the following SimVars to get information about the winch object, where an index of 0 and 1 are for the main engine, and the indices 2, 3, and 4 correspond to drums 1, 2, and 3 (depending on how many the winch has, as set up in the sim.cfg file):
ENG COMBUSTION
GENERAL ENG COMBUSTION
GENERAL ENG THROTTLE LEVER POSITION
GENERAL ENG COMBUSTION SOUND PERCENT
Note that even though you have access to an engine using indices 0 and 1 in the above SimVars, those indices currently mean nothing as the winch SimObject currently does not move. This may change in a future update.
The Parachute
Once a glider has been made airborne, they will drop the winch cable. This cable needs a parachute on the end so that it falls more slowly and safely to the ground, and as such you will need to define a parachute sim object as part of the winch package.
Specific Animations
The parachute model should be designed with 2 animations which will be used to cover the five available "states" of the parachute. These are as follows:
- State 1 - The parachute is closed
- State 2 - The parachute animates from the closed position to the open position
- State 3 - The parachute is in the open position, falling to the ground
- State 4 - The parachute animates from the open position to the "flat on the ground" position, as it hits the ground
- state 5 - The parachute is on the ground
The animation itself would be controlled by the contents of the animations.xml
file, which would be placed in the same location as the sim.cfg
file for the parachute. You can find an example of the contents of this file here:
sim.cfg
The sim.cfg file for a parachute sim object only requires a limited number of sections and parameters:
[VERSION]
[fltsim.N]
-title
,model
,texture
,ui_manufacturer
NOTE: Thetitle
parameter is what will be used in the winch object as theparachuteTitle
.[General]
-category
("Parachute")
Note on SimVars
The parachute som object has two SimVars of note that can be accessed and used:
PARACHUTE OPEN
: This SimVar will be false until the simulation sets it to true and can be used to control the transition from the closed state to the open animation state.SIM ON GROUND
: This SimVar is used to determine when the parachute has hit the ground. When true, the parachute is on the ground and so it can be used to trigger the animation between the open and flat on the ground states.
You can see an example of these SimVars being used for parachute animations here: Parachute Animation