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The Liftoff brand is built around creating the most advanced and detailed FPV drone simulation technology available. Our authentic flight behavior is the result of dozens of interconnected simulation systems working together, using state-of-the-art models based on real-world test data and CFD simulations.

Instead of scripting how a drone should fly, as many simulators do, Liftoff simulates how it actually flies. Every major component is modeled individually: the LiPo battery powering the motors, the motors driving the propellers, the propellers generating lift, the frame contributing weight and aerodynamic drag, and the flight controller continuously adjusting the drone's behavior. Together, these systems create the drone you fly virtually.

In that sense, Liftoff isn't just a drone simulator, it's a LiPo simulator, a motor simulator, a propeller simulator, a wind simulator, a flight controller simulator, and much more. Every component features true-to-life specifications that directly influence the drone's performance, making each build feel unique.

While virtual pilots sometimes ask for a gravity slider, there's far more to realistic flight than gravity alone, and we can confidently say gravity needs no sliding (it is a real-world constant after all). This page explores the technologies behind Liftoff's simulation systems and explains how they work together to create an authentic FPV flying experience.

Simulated flight forces

There are four forces that predominantly affect drone flight:

• Weight: a downwards force caused by gravity
• Thrust: a propulsive force generated by the propellers
• Drag: a force opposing the drone movement caused by air resistance
• Lift: a mechanical force generated by a solid object moving through a fluid

Weight

In an inertial reference frame, weight is a downward force that is proportional to the drone's mass and the gravitational acceleration. The drone's mass is well known based on the parts selected. Gravitational acceleration is well attested and can safely be considered constant. There are slight variations depending on location, but they do not have a noticeable effect on flight behavior and even so drones generally do not have enough range for these differences to become relevant.

Thrust

Thrust is generated by the rotating propellers of a drone. Propeller blades are shaped like airfoils. While slicing through air, they raise static pressure underneath them, thereby pushing the drone in the opposite direction.

For our Physics 3.0 update, we developed a new thrust model based on a curated database containing tens of thousands of data points from rigorous lab tests. Our model uses part specifications to determine the maximum RPM of a loaded motor, the static thrust at a given RPM, and finally dynamic thrust.

This dynamic thrust is then further adjusted by ground effects. Hovering close above a surface alters airflow, resulting in a higher pressure difference between the top and bottom side of the propellers, increasing available thrust. This effect depends, among others, on the type of surface, the distance to the surface and the pitch of the propellers.

Liftoff's drone state calculation pipeline

This approach insures a high degree of accuracy regardless of what parts a drone might be using.

Realistic motor power limits

Before Physics 6.0, the fastest setups in Liftoff combined high KV motors with oversized props, pushing beyond real-world performance. We’ve  redefined these configurations for greater realism, by calculating the point at which they go over the maximum power limits of their motors and then dialling them back as such. Each setup respects realistic motor power limits.

Drag

Our Physics 4.0 update focused mainly on drag calculations. Drag, sometimes also called air resistance, is a force that counteracts the movement of the drone. The strength of drag depends on many factors, the foremost being the surface area of the drone, as projected onto its velocity.

Projected area

One way to visualize the drone's surface area is to imagine a camera looking back towards the drone from a little further along its current trajectory. The silhouette of the drone as seen from this perspective is the projected area. While that silhouette is easy to picture when flying straight forward, it's much harder to imagine when the drone is performing freestyle tricks or rounding tight corners during races.

On the following illustration, the projected area as approximated before Physics 4.0 is shown in gray, whereas the more accurate projection from Physics 4.0 is shown in black.

Efficient estimation method

As a first approach to calculate the drone's projected area, we tried implementing a camera that continuously filmed the drone. This gave perfectly accurate data, but had a significant performance overhead. Instead, we settled on an approach where 42 different angles were pre-computed before flying, which the simulation can then interpolate between at runtime. In this way, we consistently obtain an accuracy of over 98%, with no performance impact.

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Projected area sampling process: each point on the icosphere is a sampled angle

Propeller aerodynamics

Propellers play a role in how drones handle crosswinds and turns. More blades create more drag, but also more “grip” through corners, resulting in a sharper, more responsive flying experience.

Lift

Lift is a mechanical force generated by a solid object moving through a fluid. An exhaustive physical model of lift is quite complex and still subject to discussion today. In general terms, however, lift is influenced by the fluid's properties (density, viscosity and compressibility), the surface area of the solid object, its shape and velocity, and its angle relative to the fluid flow. Lift is perpendicular to the flow and thereby also to drag.

Lift is caused by a pressure difference and a change in flow velocity. Imagine an airfoil (the typical "wing" shape) flying forward and tilted slightly backward. On the bottom side of that airfoil, the air velocity will be lower and pressure higher, while the opposite holds for the top side. This creates a vertical upward force on the airfoil.

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Visualization of the air pressure around a moving airfoil (green: low pressure, red: high pressure)

Although most drones are not specifically airfoil-shaped, they still generate lift in a similar manner. Consider a drone flying in straight line while pitched forward. Given the drone's orientation, this time the high pressure zone is above and the low pressure is below. In this case, lift actually points downwards!

Thrust, drag and lift direction in the case of a drone flying in straight line (force scale is not representative)

Flight controller

Liftoff simulators use a collection of realistic flight controllers backed by virtual recreations of the sensors one would find on modern drones: gyroscope, accelerometer, GPS, barometer, altitude sensor....

The flight controller receives the pilot's input through a radio receiver. Based on its sensor data, it then transmits a certain voltage (indirectly through ESCs) to the motors in order for them to reach a target rotation speed, resulting in a certain amount of thrust from the attached propellers. Most flight controllers use PID controllers to micro-manage motor rotation speed and correct for any disturbances. This micro-managing happens at a very high frequency and allows the drone to constantly adjust its flying, smoothly and with great precision, no matter the potential disturbances (wind, damaged propellers, collisions...).

Rather than simply replicating the superficial effects of flight controllers, our simulation code simulates their entire functioning. Our most sophisticated flight controller makes the same calculations as a real-life one. Given that PID tuning is a fundamental aspect of real-life drone tuning, the one-to-one match between simulation and reality holds great training potential.

That being said, PID tuning can be overwhelming for some players. In order to minimize the time needed from building a drone to flying it, we designed A.I. PID tuning, a feature automatically finding the optimal PID gains for a specific drone. This new, innovative A.I. feature, along with the state-of-the-art techniques from the fields of control theory and digital signal processing used in Liftoff Physics 5.0 make the Liftoff flight controller easier to use, more efficient and more precise than ever.

Battery simulation

Battery life is an important factor in drone applications and often presents a bottleneck for specific missions. An accurate and realistic simulation of the battery discharge is therefore critical part of the Liftoff simulators.

A typical lipo battery has a discharge profile that will be slightly above 3.7v when freshly charged, drop down and stabilize at 3.7v and quickly fall off at the end. We take into account the amp draw of the drone to discharge the battery and get the voltage from its discharge profile.

Besides the discharge profile, there are the continuous and burst discharge c-ratings. These determine how fast a battery can provide its energy. Flying near the continuous discharge rating of a battery will allow you to keep cruising without any adverse effects on the battery. Flying near the burst discharge rating of a battery will cause heat to build up and will also lower voltage. This will slowly recover as the battery cools down when landed or flying slowly.

Voltage sag occurs when a battery is loaded; voltage will drop and recover as the load increases and decreases. While mostly harmless, it's important to not push too hard when voltage is already low (either due to heat or due to low charge) to avoid damaging the battery.

Signal strength simulation

Two distinct radio signals are involved in drone piloting:

• A real-time video feed (emitted from the drone's VTX)
• The RC signal (emitted from the pilot's controller)

Depending on the power of the signal, its frequency, and the environment, radio signals can degrade or even be lost entirely. Consequently, the radio signal is often the limiting factor in a drone's maximal operating range.

Liftoff simulators simulate degradation of the video signal. Depending on the drone's position relative to the pilot and the shape or material of any obstacles in between, the video feed will become more distorted and noisy.

RC signal degradation can also be simulated, but is generally only enabled for industry-oriented products, as this level of realism can be frustrating in a more game-oriented setting.

Wind simulation

We’ve developed a sophisticated wind simulation that goes far beyond a simple, linear force. It features variable strength, turbulence, shifting directions, and, most importantly, a dynamic system that interacts with the world around your drone. Wind flows realistically through the terrain, just like your drone does. Flying behind a building can shield you from the gusts, or throw you into a zone of wild turbulence.

It’s not just simulating wind in a dynamic environment, we also apply this force to the pilot’s drone as Wind-Relative Drag and Asymmetric Propeller Loading.

Beyond authenticity, we designed this real-time wind system to be efficient, so it won’t strain your computer’s performance. Even better, it’s fully adjustable on the fly, giving you complete control over wind direction and strength.

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Wind correctly flows over the terrain. As an option, the wind simulation can be visualised in real time

Lens Distortion

The Liftoff simulators offer realistic  lens effect that adds realistic distortion to the flight experience, mimicking the subtle warping and curvature of real FPV cameras. This not only enhances visual immersion but also changes how you perceive and react to your flight in the simulator. 

Change the lens style in real time

Liftoff Physics development timeline

The Liftoff physics engine has been in development for over a decade, evolving from its first blueprint in 2015 to Physics 6.0 in 2025. Each iteration has been continuously refined through new research, deeper engineering insights, and ongoing feedback from more than one million users worldwide. Since this page frequently references specific Physics iterations, the overview below provides a timeline of their development and evolution over the years.

Physics 1.0: The Blueprint - 2015

• Simulation-First Design: Established the foundations of a simulation-based flight model, moving beyond purely scripted flight behavior.
• Rapid Early Iteration: Improved the physics through frequent incremental updates driven by early pilot feedback and testing.
• Building the Framework: Created the core systems and architecture that formed the foundation for every future generation of Liftoff Physics.

Physics 2.0: The Early Framework - 2017

• Flight Model Improvements: Refined lift, RPM, drag, ground effects, propwash, and drone surface area for more realistic flight behavior.
• Component-Based Flight: Made drone parts and propellers have a more predictable impact on handling, cornering, and overall performance.
• Flight Controller & Stability: Introduced a Betaflight-inspired flight controller, improved stick response, and increased physics simulation speed for greater stability.

Physics 3.0: The Lab Data Overhaul - 2018

• Thrust Rework: Rebuilt thrust calculations using new physical models based on drone components, motor behavior, and extensive wind tunnel data.
• Dynamic Flight Behavior: Introduced realistic dynamic thrust, improved drag calculations, and better weight simulation, resulting in faster falls, sharper controls, and more realistic cornering.
• Experimental Data Models: Developed new aerodynamic models using large amounts of real-world test data gathered in collaboration with independent testing labs.

Physics 4.0: Aerodynamic Accuracy - 2020

• Advanced Drag Model: Reworked drag calculations using the drone’s actual aerodynamic profile instead of simplified approximations, making each build react differently to airflow.
• Unique Flight Characteristics: Improved part-based aerodynamics, allowing frames, accessories, and attachments to have a greater impact on flight behavior.
• Lift & Control Refinements: Improved lift simulation and added more flight controller options, including adjustable motor idle speed and independent pitch/roll rate tuning.

Physics 5.0: Advanced Flight Controller - 2022

• New Flight Controller: Introduced a custom Liftoff flight controller that reduced reliance on Unity’s physics updates, improving performance and responsiveness.
• A.I. PID Tuning: Added automatic PID tuning based on flight performance, while keeping manual tuning available.
• Rate Model Support: Added support for multiple rate models, including Betaflight, RaceFlight, Actual Rates, Quick Rates, and KISS.

Physics 6.0: True Flight Simulation - 2025

• Reworked Drag & Freefall: Redesigned the drag calculations from scratch, so that drones plunge and drift in freefall with authentic gravity.
• Realistic Motor Power Limits: Capped performance math to match physical reality
• Dynamic Wind Simulator: Added a variable wind and turbulence system that interacts with the map geometry. 
• Propeller Aerodynamics: Adding more blades directly results in tighter cornering grip at the cost of higher straight-line drag.