# Verlet Tools

**Verlet Tools** leverages Verlet integration, a lightweight physics simulation technique ideal for soft-body motion, cloth, hair, tails, and other physics-driven transforms. Named after physicist Loup Verlet, this method calculates motion using position and velocity approximations, without relying on forces, Rigidbody components, or Unity’s FixedUpdate loop.

### Verlet Transform

* Each `VerletTransforms` simulates a transform’s motion using Verlet integration.
* The system is designed for stable, springy motion with low performance cost.
* Parameters such as drag, damping, elasticity, and stiffness are controlled via artist-friendly animation curves.
* Fully decoupled from Unity physics, it works on arbitrary Transform hierarchies, making it perfect for stylised secondary animation, procedural motion, and non-physical entities.

### Verlet Line

In addition to transform-based animation, Verlet Tools include **Verlet Line**, a powerful system for simulating ropes, cables, chains, and similar line-based objects.

Key features of Verlet Line include:

* **Full collision support** along the entire length of the line, allowing realistic interaction with world geometry.
* **Pinning system** with three modes:
  * *Static*: pins a line point rigidly in world space.
  * *Kinematic*: pins an object to follow a line, point’s position and rotation.
  * *Force Transfer*: connects the line with Rigidbody physics, enabling forces to flow bidirectionally (e.g., ropes dragging objects or cranes lifting loads).
* Adjustable **resolution** for tuning simulation detail and performance.
* **Custom mesh support** for the line’s profile and caps, allowing full control over visual appearance.
* Per-node parameter control via curves, enabling fine-tuning of properties like mass, damping, and stretchiness along the rope.
* Designer-friendly tools for editing control points and pins directly in the Unity Editor.

Together, Verlet Transform and Verlet Line provide a flexible, performant, and artist-friendly toolkit for physics-driven animation and simulation in Unity, enabling rich, dynamic behaviours without the overhead or complexity of traditional rigidbody physics.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://kb.heathen.group/unity/physics/verlet-tools.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.