# Detect and visualize hands from a Sprite

This example demonstrates how to load and display image sprites in a Unity scene with an [ImageView](/ui-reference/imageview.md), implement hand tracking with the [HandTracker](/api-reference/handtracker.md), and use the [HandManager](/ui-reference/handmanager.md) to render detected fingers on a 2D canvas.

{% hint style="info" %}
This is a code walkthrough of the `LightBuzz_Hand_Tracking_Picture` Hand Tracking Unity plugin sample. The plugin includes the no-code demo that has the same functionality.
{% endhint %}

#### Step 1: Create a Unity scene

Open the Unity Project you created in the [Installation](/hand-tracking-unity-plugin/installation.md) section.

Right-click on the `Assets` folder and select `Create > Scene`.

<figure><img src="/files/AWAZBZqNkgh8mdgwr3hv" alt=""><figcaption><p>Create new scene</p></figcaption></figure>

Type the scene's name. In this example, we'll use the name `PictureDemo`.

After the scene is created, right-click on the scene and select `GameObject > UI > Canvas`.

<figure><img src="/files/SOVl2RObo6YAMFPnsd5J" alt=""><figcaption><p>Add a Canvas</p></figcaption></figure>

Navigate to the LightBuzz `Prefabs` folder at `Assets\LightBuzz Hand Tracking\Runtime\Prefabs`.

<figure><img src="/files/aLOxlnZxIBjwQFtfkzwZ" alt=""><figcaption><p>LightBuzz Prefabs</p></figcaption></figure>

For this example, drag and drop the [ImageView](/ui-reference/imageview.md) and [HandManager](/ui-reference/handmanager.md) prefabs into the Canvas.

<figure><img src="/files/kiYmZTQAcNRrO6ybgFIw" alt=""><figcaption><p>Add prefabs</p></figcaption></figure>

Then, right-click on the `Hierarchy` pane and select `Create Empty`.&#x20;

<figure><img src="/files/tWKAoCSDw2MNbLtdn4Dg" alt=""><figcaption><p>Create empty component</p></figcaption></figure>

Give a name to the new component. In this example, we'll use the name `Demo`.

Then, go to the `Inspector` pane and select `Add Component`. In the search bar, type `new` and select the `New script` option.

<figure><img src="/files/aEWEKS46jXoNR0dQLnvd" alt=""><figcaption><p>Add script</p></figcaption></figure>

Type the script's name and select `Create and Add`. For this example, we'll use the name `PictureDemo`.

<figure><img src="/files/UdNUhfe2m21EVxOqjwMA" alt=""><figcaption><p>Create script</p></figcaption></figure>

#### Step 2: Initialize the visual components

Double-click on the newly created `MonoBehaviour` script and import the necessary namespaces.

```csharp
using LightBuzz.HandTracking;
using System.Collections.Generic;
using UnityEngine;
```

For this example, we'll need a `Sprite`to load an image, an [ImageView](/ui-reference/imageview.md) to draw its texture and a [HandManager](/ui-reference/handmanager.md) to visualize the detected hands.

```csharp
[SerializeField] private ImageView _image;
[SerializeField] private HandManager _handManager;
[SerializeField] private Sprite _sprite;
```

After adding the serialized fields, go to the Unity Editor to connect these fields with the `Demo` component.

At the `Inspector` pane, select the round button next to each `SerializeField`.

<figure><img src="/files/wbb9SQGCIMCPKlkEvOqr" alt=""><figcaption><p>Seriaze fileds</p></figcaption></figure>

Then, at the `Scene` tab, select the corresponding prefab. For example, for the `Image` field, select the `ImageView` prefab.

<figure><img src="/files/0jqp9uI7zQIPnTTMXJIa" alt=""><figcaption><p>Connect prefab</p></figcaption></figure>

The `Sprite` field should connect to an image sprite. You can either use the demo image sprite `lightbuzz-hand-tracking.png` included in the `Assets/LightBuzz Hand Tracking/Runtime/Media` folder or create your own image sprite.

When all fields are connected, the result should resemble the following image.

<figure><img src="/files/sLMtwNsRgYZ769zwynhx" alt=""><figcaption><p>Connected serialize fields</p></figcaption></figure>

Then, select the `HandManager` prefab, under the `Canvas`, and connect the `Image` field to the `ImageView` prefab.

<figure><img src="/files/J7W7y81Uo00EVQAPLrLA" alt=""><figcaption><p>Connect field to HandManager</p></figcaption></figure>

{% hint style="info" %}
Make sure the `Is 2D` option is selected to see the hand tracking detections in the 2D space. If the option is not checked, detections are displayed in the 3D world space.
{% endhint %}

After connecting all the fields, navigate to the `Canvas` to set the render options.

Change the `Render Mode` to `Screen Space - Camera`.

<figure><img src="/files/8xapwQLfkO58oNi2gJhH" alt=""><figcaption><p>Change Render Mode</p></figcaption></figure>

Then, set the `Main Camera,` from the Scene tab, as the `Render Camera`.

<figure><img src="/files/FKcxZ5Eyq9JlM0GAFHZu" alt=""><figcaption><p>Select Render Camera</p></figcaption></figure>

When all the render options are set, the result should look like the following image.

<figure><img src="/files/bVxgPsw5dk4FXW0xcKXy" alt=""><figcaption><p>Render settings</p></figcaption></figure>

Finally, return to the script and instantiate a [HandTracker](/api-reference/handtracker.md) to detect hands.

```csharp
HandTracker _handTracker = new HandTracker();
```

#### Step 3: Load the image

Create a `Texture2D` object with the `Sprite`'s texture.

```csharp
Texture2D texture = _sprite.texture;
```

Load the `Texture2D` object onto the [ImageView](/ui-reference/imageview.md) to show the image.

```csharp
_image.Load(texture);
```

#### Step 4: Detect hands

Pass the texture created in Step 3 to the [HandTracker](/api-reference/handtracker.md) for processing.

```csharp
List<Hand> hands = _handTracker.Load(_image.Texture);
```

The [HandTracker](/api-reference/handtracker.md) will analyze the texture and detect any hands present in the image.

#### Step 5: Visualize the hands

To display the detected hands on a 2D canvas, simply pass the detections to the [HandManager](/ui-reference/handmanager.md).  It will manage the rendering and updates required to accurately depict the hands on the canvas based on the detection data provided.

```csharp
_handManager.Load(hands);
```

{% hint style="info" %}
Steps 3 through 5 are incorporated into the `Start()` method.
{% endhint %}

#### Step 6: Release the resources

Dispose of the [HandTracker](/api-reference/handtracker.md) object to ensure that all associated resources are released.

```csharp
_handTracker.Dispose();
```

{% hint style="info" %}
In this example, the resources are released in the `OnDestroy()` method. Alternatively, you could do that with the click of a button or in the `OnApplicationQuit()` method.
{% endhint %}

### Full example code

Here is the full example code that has the same functionality as the Hand Tracking Unity plugin  `LightBuzz_Hand_Tracking_Picture` sample.

```csharp
using LightBuzz.HandTracking;
using System.Collections.Generic;
using UnityEngine;

public class PictureDemo : MonoBehaviour
{
    [SerializeField] private ImageView _image;
    [SerializeField] private HandManager _handManager;
    [SerializeField] private Sprite _sprite;

    private readonly HandTracker _handTracker = new HandTracker();

    private void Start()
    {
        Texture2D texture = _sprite.texture;

        _image.Load(texture);

        List<Hand> hands = _handTracker.Load(_image.Texture);
        
        _handManager.Load(hands);
    }

    private void OnDestroy()
    {
        _handTracker.Dispose();
    }
}
```

By following these steps, you will be able to load a `Sprite` into your application, detect hands, and finally, render these detections on a 2D canvas.


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