CartTrain

CartTrain

CartTrain is a host-only R.E.P.O. mod that connects large carts into a single-file train. Only the lobby host installs it; vanilla players can join normally and see the carts move through the game's existing cart synchronization.

How to use

Push the front of one large cart into the handle end of another. When the leading cart's handle and the following cart's front are nearly touching and the carts face roughly the same direction, they snap together automatically. A physical spring tether runs from the leading cart's real handle point to the following cart's front and maintains a one-metre gap, while virtual track guidance keeps the follower centered and aligned on the route taken by its leader.

Each active joint has a solid light-red tether visual. It follows the real handle-to-front anchors, hangs with a small natural sag, and disappears when the carts detach. The visual does not change the underlying cart physics.

Each handle can connect to one following cart, and each front can connect to one leading cart. A three-cart train is therefore Cart 1 handle to Cart 2 front, followed by Cart 2 handle to Cart 3 front.

While actively grabbing a large cart, the host can press X to isolate that cart. Its connection to the cart ahead and its connection to the cart behind are both removed. The host's CartTrain HUD appears above the inventory slots for five seconds whenever the host begins grabbing a cart.

The host can also release a cart by pulling it away from the train. Vanilla players do not have CartTrain input code, so grabbing a connected follower for the configured short delay releases its incoming tether automatically. This prevents the host's train physics from fighting a vanilla player's grab.

If a connected cart leaves the ground and begins falling, the host automatically removes both of that cart's links. A short delay and downward-speed threshold prevent ordinary ramps, slopes, and small bumps from breaking the train.

Configuration

After launching the game once with the mod installed, edit:

BepInEx/config/GrimDinosaurs.CartTrain.cfg

• AutomaticSnapDistance: how close the front/back connection points must be before snapping; defaults to 0.45 metres.
• ConnectedGap: spacing between connected cart bodies; defaults to 1 metre.
• MaximumSnapAngle: prevents sideways or backwards carts from linking accidentally.
• MaximumFollowSpeed: maximum follower movement speed.
• MaximumTurnSpeed: maximum follower turn speed.
• TetherSpring and TetherDamper: physical front-to-back tether tuning.
• PathStrength, PathDamping, and RotationStrength: virtual track guidance tuning.
• DetachKey: key used to detach both sides of the cart you are grabbing; defaults to X.
• ConnectedCartCollisions: allows directly connected carts to collide; defaults to true.
• PullDisconnectStretch: extra stretch that triggers pull-to-release; defaults to 0.3 metres beyond the normal tether length.
• VanillaGrabDisconnectDelay: delay before a follower grabbed by a vanilla player releases from its leader; defaults to 0.6 seconds.
• DisconnectWhenFalling: enables automatic fall safety; defaults to true.
• FallDisconnectDelay: unsupported falling time before disconnection; defaults to 0.25 seconds.
• FallSpeedThreshold: required downward speed; defaults to 1.5 metres per second.

Host-only multiplayer

Only the lobby host should install CartTrain. Version 1.3.0 does not send any custom CartTrain Photon RPCs, so vanilla clients do not need the mod and do not receive missing-RPC errors. The host owns all connection state and follower physics; R.E.P.O.'s existing cart networking synchronizes cart movement to the other players.

Vanilla players see and interact with the carts, but they do not see the light-red tether or CartTrain HUD and cannot use the X keybind. Those custom visuals and controls exist only on the host's game.

Installation

Install on the lobby host with a -compatible mod manager, or place CartTrain.dll in the host's:

R.E.P.O