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Changelog and release notes

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What changed in each version of Kart Racing Drifting Physics.

1.1

Adds multiplayer, kart collisions, surfaces and more. Built for Unreal Engine 5.7. Coming in 1.1

Multiplayer

  • Server-authoritative multiplayer with client prediction, built on Unreal’s Chaos Networked Physics. Your own kart reacts to your input instantly, and the server has the final word.
  • It switches on by itself in a networked game once Enable Physics Prediction is on. Single player behaves exactly as before.
  • Corrections include the drift and boost state, so drifting stays smooth under latency.
  • Other players’ karts run the same simulation on your machine, so their front wheels steer and the kart leans just like yours.
  • Bumps between karts are predicted for both karts.
  • The kart itself needs no replication logic in your Blueprints. SetBoost works from the server (boost pads, items) and from the owning client (drift boosts).
  • IsUsingNetworkedKartPhysics tells your Blueprints whether a kart runs networked.

Setup and testing: Multiplayer setup.

Gameplay and driving

  • Kart Intents: SetKartLinearDamping, ClearKartLinearDamping, AddKartImpulse, AddKartAngularImpulse, StunKart, ClearKartStun and TeleportKart. Mud, knockbacks, spin-outs, stuns and respawns with one Blueprint node each, networked for you. See Boosts and items.
  • Surface Properties: drag per physical surface type (asphalt, mud, offroad), set up in the details panel with no Blueprint logic. CurrentSurfaceType tells you the surface under the kart, for dust or tyre sounds.
  • Wall Hit settings: speed loss on wall contact, an optional bounce and yaw kick, and the OnKartWallHit event. See Surfaces and walls.
  • Kart Collision settings: choose Arcade Bump (default), Physics or Ignore. Arcade Bump is a designed, tweakable bump with its own Bump Mass weight class. See Kart collisions.
  • Suspension Ignores Other Karts (on by default): a kart no longer climbs onto another kart’s body.
  • Trace Channel: pick the collision channel for the suspension and ground traces (default Visibility). See Suspension.
  • Suspension Locations can now have more or fewer than four entries.
  • Kart Mass Kg: the kart’s mass is now editable (default 1000 kg, which all forces are tuned for).
  • Tick Rate Independent Acceleration: keeps the acceleration the same if you use another async physics rate than 60 Hz.
  • The kart body never falls asleep, so it always reacts to forces.

Visuals

  • Smooth Visual State (on by default): wheels, lean and other visual values glide with the kart body at 120 Hz, 144 Hz or uncapped framerates. See Visual smoothing.
  • Other players’ karts show their full hop, even though the network reveals the takeoff late.
  • IsVisuallyInAir and GetVisualBodyLocation: new Blueprint functions for cosmetic logic that should follow the visible kart, such as the wheels’ in-air pose. The shipped Blueprints use both.
  • OnKartBump, BumpTimeRemaining and LastBumpPushLocal drive bump animations, sounds and effects on every machine.

Setup changes for existing projects

  • Version 1.1 requires Unreal Engine 5.7.
  • The physics tick is unchanged: keep Tick Physics Async on and Async Fixed Time Step Size at 0.016667 (60 Hz).
  • Wall slowdown and offroad drag now live in the kart settings (Wall Hit, Surface Properties). The 1.0 BP_KartPawn wall logic and the example kart’s offroad logic are gone. If your own kart Blueprint copied them, remove them and use these settings instead.
  • A Wake All Rigid Bodies node on Tick is no longer needed.

For multiplayer only, turn on Enable Physics Prediction (Project Settings > Physics > Replication > Physics Prediction) and add this to Config/DefaultEngine.ini, then restart the editor:

[ConsoleVariables]
p.Chaos.AccelerationStructureCacheOverlappingLeaves=0

Single player projects need neither. Why the line matters: Troubleshooting.

Blueprints and example project

  • BP_KartPawn includes an OnKartWallHit example, and its drift boost works in multiplayer.
  • Offroad on the example track uses a Surface Properties row, and its offroad physical material now uses the project’s Offroad surface type.
  • The example project’s reset uses TeleportKart.

1.0 (July 2025)

Initial release on Fab, for Unreal Engine 5.5.

The yellow rigged kart drifting on the desert track, with blue drift sparks at its rear wheels
  • Polished drift mechanics: Hop, steer, and drift on any surface. Drifting charges your boost automatically and feels exactly like you expect from the best kart racers.
  • Framerate independent physics: Whether you’re running at 30 or 240 FPS, the physics stay consistent. Springs, timers, and drift behavior remain consistent thanks to asynchronous physics. See how the async physics tick works.
  • Assets included: A fully rigged and procedurally animated skeletal mesh is included, with textures. Game ready drifting particles are included as well, so you are good to go!
  • Elaborate camera system: The camera locks into drifts perfectly and stays smooth even over rough ground. No shaking, no lag, just satisfying visuals that follow every turn.
  • Flexible and developer friendly: Built in C++ with a clear architecture and a child Blueprint class for easy extension. All gameplay behavior, input handling, and visual effects are cleanly separated and highly customizable. Easily recreate any arcade racing feel.
  • Complete race track included: Includes a handcrafted desert circuit built with spline roads and offroad functionality. Perfect for testing or jumping right into gameplay.
  • Tuning in the details panel: Drift boost stages, drift and turning curves, speed, acceleration and suspension. Start with Drifting and Driving.
  • Boosts for items and boost pads: One SetBoost Blueprint node. See Boosts and items.

Not using the plugin yet? Get it on Fab.