PhysioBrush is a high-performance secondary motion solution for Unity. It automates character physics setup (hair, tails, clothing, breasts, etc.) through direct vertex painting, bypassing the need for manual rigging or skinning in external 3D software.

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## 🛠️ Getting Started: Where is the Editor Window?

To start using PhysioBrush in your project:

1. In the Unity top menu bar, navigate to:

   **`Window` -> `PhysioBrush Demo` -> `PhysioBrush Editor`**

2. A new editor window will open (titled **PhysioBrush Demo**).

3. Select any Character model or 3D object in your Hierarchy. If the object does not have PhysioBrush components yet, you will see a **"+ Setup Physics for [Object]"** button.

*Tip: For a smoother workflow, drag and dock the PhysioBrush window next to your Inspector or Scene View.*

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## 🚀 Step-by-Step Setup Guide

1. **Initialize Setup**: Click the **"+ Setup Physics for [Object]"** button. This automatically:

   - Adds the `PhysioBrushRunner` component to your object.

   - Creates a settings asset to store your configurations.

2. **Add Physics Island**: In the Island Manager section of the window, click **"+ Add Island"** and choose a preset/type (e.g., *Tail* or *Jiggle*).

3. **Paint Influence Weights**: Click the **"PAINT"** button. Your object will render in a solid color showing the paint brush:

   - Paint the areas you want physics to affect (e.g., hair strands, dress, tail).

   - Use the **Brush Alpha** slider to control movement flexibility (1.0 = maximum movement, 0.0 = static/no movement).

4. **Position Anchors**: Use the Green Editor Gizmos in your Scene View (Root and Tip markers) to define the direction and length of the generated bone chain.

5. **Bake & Apply**: Click **"Stop Painting"**. PhysioBrush will auto-generate the bone hierarchy and bake skin weights dynamically.

6. **Test**: Enter **Play Mode** in Unity to see the secondary motion simulate in real time.

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## 🔒 Demo Version Limitations

This Demo version is for evaluation purposes only. The following features are locked:

*   **Body Collision Generator**: Automatic limb capsule collider generation is disabled.

*   **External Physics Export**: Exporting generated dynamic bones to external rigid bodies or non-Physio setups is locked.

*   **Production Parameter Tuning**: The following options are locked or fixed to default values in the Inspector:

    - *Physics Intensity* (clamped to default)

    - *Collider Scale* (clamped to default)

    - *Interpolation* (Popup is disabled)

    - *Global Collider Scale* (clamped to default)

    - *Weight Sensitivity* (clamped to default)

    - *Dynamic Exclusion* (clamped to default)

👉 **To unlock all professional production controls, collision generation, and export utilities, get the Full Version here:**

[**PhysioBrush on the Unity Asset Store**](https://assetstore.unity.com/packages/tools/physics/physiobrush-procedural-bone-physics-jiggle-generator-375898)

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## 🔍 Troubleshooting

*   **Model is Stretching/Distorting**: Verify that the character's root scale is set to `(1, 1, 1)`. Non-uniform root scales can throw off joint coordinate space calculations.

*   **No Movement in Play Mode**: Check the generated `PB_Bone_...` gameobjects under your character root in Play Mode. Ensure `Is Kinematic` is unchecked on the rigidbodies (except the root anchor).

*   **Missing Shader/Pink Materials**: The vertex painting tool requires the `Hidden/PhysioBrush_Demo/VertexColor` shader. Make sure `PhysioBrush_VertexColor.shader` is included in the project assets.