Former Rockstar Animator Pulls Back Curtain on GTA 6 Physics

In a detailed breakdown, ex-Rockstar Games animator Mike York explained the engineering behind the jiggle physics featured in Grand Theft Auto 6 that has spawned countless viral clips and memes. What sounds like a simple feature is actually a sophisticated marriage of two different simulation systems running simultaneously inside the developer's proprietary RAGE engine.

According to York, every character in GTA 6 has an invisible skeleton made of "bones", mathematical points connected in a hierarchy that defines how the character model can move. Your character's spine connects to shoulder bones, which connect to arm bones, and so on. This bone structure is what allows animators to create movement.

The next layer up is where it gets interesting for realistic body physics: Rockstar took it further by animating additional physics-driven bones specifically for soft tissue simulation. These bones aren't manually animated frame by frame. Instead, they respond dynamically to the character's movement using physics calculations.

Using Lucia walking across a yacht in the second GTA 6 trailer, for example, York explains that her main skeleton is following the running animation of an animator creator. Layered on top of that, physics bones are calculating how soft tissue would realistically move based on momentum, gravity, and speed. The RAGE engine is doing these calculations in real-time, every frame, for every character on screen.

York emphasizes that this physics calculation occurs in real time, meaning it's genuinely responsive to what's happening in the game world. So when you see a GTA 6 trailer scene captured entirely on base PS5 with dozens of NPCs on a beach, each with realistic body physics, you're watching the RAGE engine performing thousands of physics calculations per second across all those characters simultaneously.

However, York explains that GTA 6 is using pre-calculated cloth simulations as well. Pre-calculated simulations are exactly what they sound like. The engine has computed the physics ahead of time, and it's baked into the animation. York theorizes that this is why Lucia's dress flows the way it does every time she moves in the trailer.

This hybrid approach is technically complex, but gives Rockstar the best of both worlds: cinematic control when they need it, and dynamic realism when players are just causing mayhem in Vice City. What's even more amazing is how fluid this all looks when it's happening at 30 times per second for every character. Even the ones in the background that you're barely looking at.

The hybrid pre-calculated and real-time approach means Rockstar doesn't have to choose between "looks amazing in cutscenes" and "responds realistically to gameplay." They get both. A character can look perfect in a carefully directed story moment, then transition seamlessly into player-controlled chaos where physics respond naturally to whatever ridiculous thing you're doing.

Previous Grand Theft Auto games had some soft-body physics, but the way York is explaining things, nothing approaching this level of sophistication or consistency across all characters - which is generally the recurring theme with this game overall, isn't it? This is the kind of technical foundation that enables immersion. Players won't consciously think "wow, the jiggle physics are using a hybrid simulation system." They'll just feel like the world is real.

Perhaps this is the reason Rockstar is targeting 30 FPS on consoles, rather than 60. Running these physics calculations for dozens of detailed characters simultaneously is computationally expensive, and that's before you add in the ray-traced lighting, the complex AI systems, the detailed environment simulation, and everything else happening in the world.

York has previously explained that Rockstar's philosophy is to "squeeze every little freaking thing they can out of it" rather than compromise visual fidelity for higher frame rates. The jiggle physics system is a perfect example of that trade-off. You could simplify the physics, reduce the number of bones being calculated, or limit which characters get the full treatment at the cost of the cohesive realism that makes GTA 6 look generational.

Former Rockstar technical director and industry veteran Obbe Vermeij supported this approach, noting that 30 FPS allows nearly double the polygon budgets and physics complexity compared to games targeting 60 FPS. When you're trying to create the most immersive open world ever made, that extra computational headroom matters enormously.

TLDR; when the internet jokes about how Rockstar spent over a decade on jiggle physics, they aren't entirely wrong. The bone-based physics system York described isn't something you build in a few months. This is the kind of foundational technology that defines an engine generation. The RAGE 9 engine powering GTA 6 has had these systems in development since before Red Dead Redemption 2 launched, with the systems constantly refined and expanded.

So, for the jiggle physics that everyone's talking about? That's just the most visible evidence of how thoroughly Rockstar has rebuilt their animation technology for the current generation of hardware. When GTA 6 launches on November 19, 2026, players will likely take the realistic character movement for granted within hours. That's the goal. The physics calculations happening under the hood, all of that complexity exists to create a world that feels real.

According to someone who actually built these systems for Rockstar, that feeling is worth whatever price they set, worth whatever frame rate compromise they make, and worth every single day of the wait.