Fixes loaded carts in R.E.P.O. feeling heavy, sluggish, or slow to push and turn.
Empty cart turns at roughly 4 rad/s. Fill it with 70 valuables and it drops to roughly 0.4 rad/s — a 10x stall from the payload alone. A full cart barely corners, feels heavy to push, and takes forever to get up to speed.
PhysGrabCart.rb.mass is 8 kg (4 kg while grabbed). 70 valuables at 0.5 kg each is 35 kg sitting inside an 8 kg container. Unity's contact solver gives the payload most of the impulse share any time the cart tries to move, and items physically block the cart from reaching the velocity that CartSteer writes each tick.
Whether this is a bug or an intentional weight mechanic isn't clear. The game already halves cart mass on grab (CartMassOverride(4f)), suggesting the developers wanted a light, responsive cart. Payload-induced drag just wasn't compensated for.
Cart Rigidbody mass is scaled 6x at PhysGrabCart.Start, with a matching prefix on CartMassOverride so the grabbed/idle ratio stays consistent. Contact resolution stops draining the cart's momentum into the payload, and a loaded cart turns close to the empty-cart rate.
In-cart items sync to cart velocity every physics tick — including the cart's angular velocity at each item's position — so items follow through turns instead of sliding into cart walls or lagging behind.
Host-side only. Install on the host and every player in the lobby benefits. Zero config.
Pairs with CartSpeedSync: that mod raises the scripted top speed, CartFix makes the cart reach it under load.
Patches PhysGrabCart.Start, PhysGrabCart.CartMassOverride, PhysGrabObjectImpactDetector.FixedUpdate. Should coexist with any mod that doesn't touch those.