Server-authoritative ropes, ziplines and physics carry for listen and dedicated servers - C++ with a Blueprint API.

APIAPI's Replicated Rope & Physics-Carry Kit gives a multiplayer Unreal Engine project ropes and carried objects that look the same on every machine, with the server deciding every outcome.

• Replicated ropes. Tethers, cuttable ropes and ziplines on a position-based rope solver that runs on every machine and is corrected toward the server's key particles. Anchors on static or moving actors; a cut rope splits into replicated pieces; players who join late see every rope as it is.

• Ziplines. Mount, ride and dismount with server validation, on a Character (through the bundled Character Movement adapter) or on any pawn with a movement component.

• Physics carry. Grab, hold, drop and throw physics objects; the holder sees the object move at once, everyone else follows the server; held objects are kept out of walls; two players grabbing the same object get one winner.

• Requests with replies. Cut, mount, grab, drop and throw are requests the server validates (reach, line of sight, throttling); every request resolves exactly once on the requesting machine, with a reason when it is refused.

• Diagnostics. An in-game network debug overlay, an editor validator for rope and carry setups, and log lines with a fix hint for every problem the kit can explain.

• A demo map. Open L_UKRopeDemo, press Play as Client with two players, and try every rope type and the crate room.

Multiplayer behaviour is verified by the bundled automation suite in listen-server and dedicated-server sessions on Unreal Engine 5.6, 5.7 and 5.8.

Engine plugins

Engine plugins the kit enables in its .uplugin. They ship with Unreal Engine, so there is nothing extra to install:

• Online Subsystem Utils (OnlineSubsystemUtils): used only by the kit's automated test module (UKRopeTests) to run listen-server and dedicated-server test sessions; the runtime and client modules do not use it

• Data Validation (DataValidation): used only by the kit's editor module (UKRopeEditor) to validate rope and carry setups in the editor; it is enabled for Editor targets only, so games and servers never load it

• Enhanced Input (EnhancedInput): binds the demo map's character input (move, look, jump, cut, grab, drop, throw) and lets the kit's editor-only test module UKRopeTests (UncookedOnly) drive that input in its automation tests; the kit's runtime and client modules do not use it

Technical details

• Engine versions: Unreal Engine 5.6, 5.7 and 5.8 (one archive per engine).

• Platforms: Win64; Linux (compiled for Linux clients and dedicated servers; the automation suite runs on Windows).

• Code modules: UKRope (runtime), UKRopeCMCAdapter (runtime, Character Movement adapter), UKRopeClient (client only: rope visual, debug overlay), UKRopeEditor (editor validator), UKRopeTests (editor-only automation suite).

• Network replicated: yes - default replication and Iris.

• Number of C++ Classes: 73

• Number of Blueprints: 4

• Supported development platforms: Win64

• Supported target build platforms: Win64, Linux

• Documentation: in the plugin's Docs/ folder - install, quick start, API guide, testing, network model and known limits - and online at https://apiapi.kr/unreal/rope-carry-kit/docs.

• Support: https://apiapi.kr/support

Important notes

• Unreal Engine 5.8 is Epic's last planned UE5 release; UE6 compatibility is not promised.

• This product contains no third-party software.