Rope Bundle 2D - Bridges, Chains & Rope Cutting

Rope Bundle 2D is a 2D rope physics asset for Unity. Add ropes, chains, cables, wires and elastic strings that hang under gravity, collide with Collider2D shapes and push dynamic Rigidbody2D bodies. A Verlet rope solver runs on Physics2D, so you don't have to write and tune your own rope physics.

Build hanging ropes, swinging chains, rope bridges, winches and cut-the-rope mechanics for platformers and physics puzzle games. Set up each rope in the inspector, control it from C# at runtime, and render it as a LineRenderer line, a textured strip or a chain of link sprites. Works in the Built-in Render Pipeline and URP.

Create a 2D rope, chain or cable in a few clicks

Choose GameObject > Serpentower > Rope and pick a preset: Rope, Chain, Cable or Elastic. The menu builds a ready 2D rope with a pivot to hang from, a node prefab, a profile and a LineRenderer with a material. Move the pivot, press Play, and the rope falls, hangs and drapes over your colliders. A basic rope needs no code and no extra material.

Rope physics presets: Rope, Chain, Cable

The feel of a rope lives in a RopeProfile asset: segment length, thickness, stretch resistance, bend resistance, snap-back damping, friction, mass, damping, gravity scale and solver substeps. Many ropes can share one profile, so one change updates all of them. A rope can also keep its own values. Feel values can change from C# at runtime and apply on the next physics step, with no rebuild.

The four presets cover the common cases. Rope is a light, flexible line. Chain collides as beads and grips harder. Cable resists bending and settles quickly. Elastic stretches under load like a rubber band.

Attach ropes to objects and Rigidbody2D bodies

Pin either end of a rope to an object, or leave it free. A static or kinematic object holds the rope like a pin. A dynamic Rigidbody2D on an anchor is pulled by the rope and can still swing, which makes swinging weights and pendulums easy. Put the anchor on a child object to hang the rope from a hook point on a body. Node Attachments pin any node in the middle of the rope to an object, so one rope can run through several fixed points.

Rope winch: reel in and pay out at runtime

A winch makes the rope longer or shorter at one end while the game runs. Set a target length from C#, and the rope moves towards it at the reel speed. Pins stay on their nodes while the rope changes length. Each added or removed node raises an event.

Cut the rope at runtime

Rope.Cut(segment) splits a rope at any segment and returns the cut piece. The piece keeps its speed, its pins and the end anchor, and it keeps falling. The OnRopeCut event reports every cut. Turn on Destroy Cut Piece to remove the piece at the end of the frame instead. Use it for cut-the-rope puzzles, breaking rope bridges and ropes the player slices. The demo scenes include rope bridges.

2D rope collision and contact events

Pick the collision layers the rope hits. Choose Thread, where each segment collides as a capsule, or Beads, where each node collides as a circle. Friction decides whether the rope slides off edges or catches on them. Give the rope mass, and it pushes dynamic Rigidbody2D bodies it lies on. OnRopeContactBegan and OnRopeContactEnded fire once per collider, and GetTouchedColliders lists current contacts without allocating.

Rope rendering: LineRenderer, textured strip or chain sprites

RopeLine draws the rope through a LineRenderer and can match its width to the rope thickness. RopeMesh generates a mesh in two modes. Strip repeats a rope texture along the line. Chain lays one link sprite per link, keeps each sprite's proportions and supports overlap for interlocking chain art. Link Order picks which sprite each link shows: Repeat, Ping Pong, or your own order written as a small C# class. Line and mesh are interpolated between physics steps, so the rope moves smoothly when the frame rate is higher than the physics rate. RopeMesh also draws in edit mode, so you see the rope in the Scene view without pressing Play.

Built-in Render Pipeline and URP support

Rope Bundle 2D works in the Built-in Render Pipeline and in URP with the 2D Renderer or the Universal Renderer. The package has no URP dependency and compiles without it. The demo materials use Unity's built-in Sprites/Default shader, so they do not turn pink in either pipeline and need no upgrade step.

Documentation, C# API and tests

A 41-page manual covers every inspector field, property, method and event, with C# examples for the winch, rope cutting, contact events and changing rope feel from code. The package ships with EditMode and PlayMode tests. Projects on version 1.x can update to 2.0 with the migration steps in the manual.

Use cases

Rope Bundle 2D fits 2D platformers, physics puzzle games and cut-the-rope style games:

- hanging ropes, chains and cables

- swinging weights and pendulums

- rope bridges that sag and break

- winches, cranes and pulleys that reel rope in and out

- ropes and chains the player cuts