# mouseScrollDelta

> The current mouse scroll delta. (Read Only)

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md)
* **Assembly:** UnityEngine.InputLegacyModule

```csharp
public static Vector2 mouseScrollDelta { get; }
```

### Remarks

**Note**: This API is part of the legacy Input Manager. The recommended best practice is that you don't use this API in new projects. For new projects, use the Input System package. To learn more about input, refer to [Input](/engine/6000.7/script-reference/unityengine/input.md).

[\_mouseScrollDelta](/engine/6000.7/script-reference/unityengine/input/mousescrolldelta.md) is stored in a [\_y](/engine/6000.7/script-reference/unityengine/vector2/y.md) property. (The [\_x](/engine/6000.7/script-reference/unityengine/vector2/x.md) value is ignored.) [\_mouseScrollDelta](/engine/6000.7/script-reference/unityengine/input/mousescrolldelta.md) can be positive (up) or negative (down). The value is zero when the mouse scroll is not rotated. Note that a mouse with a center scroll wheel is typical on a PC. Modern `macOS` uses double finger movement up and down on the trackpad to emulate center scrolling. The value returned by [\_mouseScrollDelta](/engine/6000.7/script-reference/unityengine/input/mousescrolldelta.md) will need to be adjusted according to the scroll rate. In the example below a `scale` of /0.1f/ is used.

Note that [\_mouseScrollDelta](/engine/6000.7/script-reference/unityengine/input/mousescrolldelta.md) is read-only.

### Examples

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

 // Input.mouseScrollDelta example
 //
 // Create a sphere moved by a mouse scrollwheel or two-finger
 // slide on a Mac trackpad.

public class ExampleClass : MonoBehaviour
{
    private Transform sphere;
    private float scale;

    void Awake()
    {
        GameObject go = GameObject.CreatePrimitive(PrimitiveType.Sphere);
        sphere = go.transform;

        // create a yellow quad
        go = GameObject.CreatePrimitive(PrimitiveType.Quad);
        go.transform.Rotate(new Vector3(90.0f, 0.0f, 0.0f));
        go.transform.localScale = new Vector3(4.0f, 4.0f, 4.0f);
        go.GetComponent<Renderer>().material.color = new Color(0.75f, 0.75f, 0.0f, 0.5f);

        // change the camera color and position
        Camera.main.clearFlags = CameraClearFlags.SolidColor;
        Camera.main.transform.position = new Vector3(2, 1, 5);
        Camera.main.transform.Rotate(0, -160, 0);

        scale = 0.1f;
    }

    void OnGUI()
    {
        Vector3 pos = sphere.position;
        pos.y += Input.mouseScrollDelta.y * scale;
        sphere.position = pos;
    }
}
```