Piper L-4A "Grasshopper" (J3 Cub)

Cliffhanger31 · Friday at 08:00 PM

Hey everyone

I've been working on a full-fidelity Piper Cub mod, specifically the WWII L-4A variant, for quite some time. Now that it's getting close to completion, I figured it was time to share it with you all. I started this project because I wanted to learn about aircraft physics and flight modeling, so I chose the simplest aircraft that came to mind, thinking I would just write the EFM and use a free 3D model as a stand-in. Eventually, I got tired of looking at ugly models and decided I wanted to take a stab at 3D art, so I ended up creating a 3D model, textures, and animations to go along with the EFM.

Currently, the Cub mod features a fully custom EFM that uses a blade-element theory approach to model aerodynamics. This method divides the aircraft's wings, tail, fuselage, propellers, and other surfaces into multiple components and calculates the lift and drag forces acting on each aerodynamic component. These forces are then summed up to produce the total force acting on the aircraft every frame. This approach is really cool because of its simplicity and how it naturally captures complex flight dynamics that occur at high angles of attack, such as spins or snap rolls, without relying on large datasets stored in lookup tables. The EFM also includes a realistic simulation of the Continental A-65 engine and propeller, including effects like p-factor, gyroscopic precession, and propwash.

While my primary focus has been on the flight model, I've also taken some time to make sure the model looks decent and is realistic to the L-4A. I chose this particular variant so it can be used in various WWII scenarios, whether early or late in the war, and it will have skins appropriate for the ETO, PTO, and MTO. Additionally, I've included some M1A1 Bazookas, so it has at least a bit of firepower, and we can recreate the exploits of Bazooka Charlie. Some parts of the 3D model are still WIP, but here are some pics of the current state of the Cub.