From v2.3.0 on, Just Like The Simulations - The Great War has a scripted jumppack functionality.
This guide is going to go through on how the system works in the gameplay, and how you can make your own gear compatible with it if you are familiar with modding.
It is important to note that this system is still work-in-progress, so things may change over time in which case, this guide will be updated as well.

This new update brings functionality to the jumppacks of JLTS - TGW.
Simple, right?
Well, not as simple as it sounds.
With this system, the goal was to bring an authentic and relatively easily usable jumppack functionality into the game while still requiring practice to really master it's usage.
So let's dive into it.

The first and most obvious thing on the screen to discuss is the energy display HUD element.
It's actually registered into the layout editor of the game so you can move it around if you prefer it being somewhere else.

This element is only displayed if the jumppack system is enabled and the player has one equipped.
It consists of two bars:

• Light gray / white
  Represents how much energy the jumppack currently has.
• Red
  Displays something best described as the minimum required energy for ignition. This means is that if the player tries to make a jump while the energy is below the required minimum, the jumppack "fails to ignite" and it results in draining all remaining energy (even if the energy required for your jump is lower than the ignition minimum). So always make sure to take a quick look at the energy level before trying to jump!

The jump itself can be performed using the Jump keybinding (default: Ctrl + SPACE).
The trajectory of the jump is defined by two values, the vertical and directional components.
The vertical component is how high the player wants to be at the top of the parabola of the trajectory. And the directional component is how far from the starting point the player wants to land.
Both in METERS

The characteristics of the jumppacks (vertical and directional limits, energy capacity, recharge rate and steering capabilities) are defined in the configuration and can only be changed through modding.

Important to note:

• There is a 6th character value of the jumppacks derived from the vertical and directional limits. It's the "jump budget" and is either the sum of the directional limit and vertical minimum or equal to the value of the vertical limit (depends on which way gives the higher budget)
  
• From the two defining components of the jump, the vertical element is the most reliable, the directional is more rough (it's likely to land in a little smaller distance) and it's also changed by the mid-jump steering if a jumppack is capable of it
  
• The general direction of the jump depends on the direction of movement in the moment of jumping, therefore if the player is not moving, the jump will happen in vertical direction only

Now how to set these values?

• Default
  The default settings for every jumppack when first equipped are: vertical = vertical limit / 2 and directional = directional limit / 2.
  
  
• Quick set jump profiles
  
  Every player has 4 quick settings profile that can be changed by using the Cycle quick jump set profile keybind (default: Alt + CAPSLOCK). More on these in the Settings section of this guide.
• Precise settings dialog
  

While you are in the air there are a few things to note.

• Units are exposed and vulnerable in the air so be mindful when setting the jump height
  
• If the player is stuck in the ceiling of a building or just want to stop completely for whatever reason, the Emergency stop keybinding can be used (default: Win) to nullify the velocity within a few moments but it happens at the cost of draining all remaining energy from the jumppack
  
• If a jumppack model is capable of mid-air steering, you can modify your landing place by steering with the traditional movement keys (WASD), how hard you can alter it is depending on the jumppack model

Normally the player would be hurt or even die from fall damange so for the duration of the jump the player unit can't take collision damage (getting shot still counts), it's only reactivated after landing.
Keep in mind that you can only land on non-PhysX objects such as ground, or buildings. If you land on a vehicle for example you'll keep floating on top of the vehicle (or straight up die from collision damage if ACE3 is loaded).
After landing, the jumppack will start to recharge after some delay (unless it's a non-recharging one).

• Clone marshal commander jumppack
  
  • Vertical minimum: 2 meters
    
  • Vertical limit: 30 meters
    
  • Directional limit: 15 meters
    
  • Jump energy budget: 30 units
    
  • Minimum energy for ignition: 5 units
    
  • Maximal energy capacity: 50 units
    
  • Recharge rate: 2 units / second
    
  • Steering coefficient: 0.02
  
  
  
• Clone trooper jumppack
  
  
  • Vertical minimum: 2 meters
    
  • Vertical limit: 15 meters
    
  • Directional limit: 50 meters
    
  • Jump energy budget: 52 units
    
  • Minimum energy for ignition: 10 units
    
  • Maximal energy capacity: 100 units
    
  • Recharge rate: 1 unit / second
    
  • Steering coefficient: 0.1
  
  
  
• Clone trooper "chicken" jumppack
  
  
  • Vertical minimum: 2 meters
    
  • Vertical limit: 50 meters
    
  • Directional limit: 50 meters
    
  • Jump energy budget: 52 units
    
  • Minimum energy for ignition: 25 units
    
  • Maximal energy capacity: 150 units
    
  • Recharge rate: 2 units / second
    
  • Steering coefficient: 0.06
  
  
• Clone trooper JT-12 jetpack
  
  
  • Vertical minimum: 2 meters
    
  • Vertical limit: 50 meters
    
  • Directional limit: 50 meters
    
  • Jump energy budget: 52 units
    
  • Minimum energy for ignition: 15 units
    
  • Maximal energy capacity: 150 units
    
  • Recharge rate: 2 units / second
    
  • Steering coefficient: 0.1

Keys:

• Jump
  Key to perform jump
• Emergency stop
  Stop completely in the matter of seconds at the cost of losing all remaining energy
• Settings
  Open the precise jump settings dialog
• Cycle quick jump set profile
  Cycle through the 4 quick settings profiles

Globally synced options:

• Jumppack system main switch
  Determines if the jumppack scripts should be running Can be -Enabled -Disabled
• Allowed stances
  Determines which stances you can launch a jump from Can be -Standing -Standing and croutch -Standing, croutch and prone
• Custom energy consumption
  If set to true, the energy consumed by jumps is altered with the custom coefficient
• Custom coefficient
  Coefficient for custom energy consumption Can be 0.1 - 2.0

Local options:
Technically there are 8 options but they are actually the same 2 options repeated for all 4 quick set (standard jump, high jump, long jump, quick descent) profiles so only the 2 essentially different parts are listed here as a guide.

• Ratio
  Sets the ratio between the directional and vertical elements It must be in the format of directional,vertical (eg.: 1,1) The composing numbers should be integer values
• Coefficient
  When the quick jump settings are changed with the cycle key, the functions first calculate the largest possible jump with the given ratio and the jump budget of the jumppack then the resulting components are multiplied with this coefficient Can be 0.1 - 1.0

• This system is still heavily work in progress so bugs may appear, please report them on discord!
  
• One of the known issues (probably without fix) is that the players can only see the light of their own jumps at night, this is due to the way a script command works and it's probably not worth fixing it.
  
• The jump effects (smoke and fire) are actually not attached to the backpack but rather to the player model so they don't follow the leaning of the upper body. This is an engine limitation.
  
• Jump settings and energy variables are stored locally for every player and are not sycnronised over the network in mutiplayer. This means that if a player drops a jumppack with half energy and custom jump settings and another player picks it up, the jumppack will have max energy and default settings for the other player. If it's dropped and again and picked up by the first player, they will get the settings and energy it was originally dropped with.
  
• Jumppacks only recharge while they are equipped.
  
• The packs can't be ignited again mid-jump.

• A field manual entry was added with a short explanation
  
  
• A new option was added to objects with inventory space (ammo boxes, vehicles etc.) in 3DEN to make them jumppack recharge stations. This adds a scroll wheel menu option to the object in game.