# Slide(Vector2, float, SlideMovement)

> Slide the Rigidbody2D using the specified velocity integrated over deltaTime using the configuration specified by slideMovement.

## Definition

* **Type:** Method
* **Namespace:** [UnityEngine](/engine/6000.3/script-reference/unityengine.md)
* **Assembly:** UnityEngine.Physics2DModule

```csharp
public Rigidbody2D.SlideResults Slide(Vector2 velocity, float deltaTime, Rigidbody2D.SlideMovement slideMovement)
```

### Parameters

**** (\[Vector2]\(/engine/6000.3/script-reference/unityengine/vector2)): The velocity to use when the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) is sliding.**** (\[float]\(https\://learn.microsoft.com/dotnet/api/system.single)): The time to integrate the `velocity` over.**** (\[SlideMovement]\(/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement)): The configuration controlling of how the slide should be performed.

### Returns

| Type                                                                                    | Description                        |
| --------------------------------------------------------------------------------------- | ---------------------------------- |
| [SlideResults](/engine/6000.3/script-reference/unityengine/rigidbody2d/slideresults.md) | The results of the slide movement. |

### Remarks

The intent of this method is to provide fairly sophisticated movement with minimal API.  Movement includes sliding along surfaces within specific slope angles, surface snapping, gravity and slippage on slopes within certain angles. All contacts are handled automatically. This method can move a [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) of any [body type](/engine/6000.3/script-reference/unityengine/rigidbodytype2d.md) and either immediately change the position, defer the position change until the simulation step or simply return the calculated position.

The following is a completely breakdown of the logic of this mechanism:

The [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) can be moved using the specified `velocity` integrated over the specified `deltaTime`. When this happens, any contacts with other [Collider2D](/engine/6000.3/script-reference/unityengine/collider2d.md) will cause the appropriate change in direction (velocity) to occur with no friction or bounce used. This change in direction and subsequent continuation of movement using the remaining velocity after the contact is known as a "slide". This is a single slide iteration. A "slide" will only occur if the slope angle fo the surface is less than that defined by [Rigidbody2D.SlideMovement.surfaceSlideAngle](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/surfaceslideangle.md).  The maximum number of slide iterations allowed is controlled by [Rigidbody2D.SlideMovement.maxIterations](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/maxiterations.md).

When a slide iteration occurs, the velocity used to perform the move may cause the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) to move away from a [Collider2D](/engine/6000.3/script-reference/unityengine/collider2d.md) surface. This would be seen if the slide moves over a small ramp or is directed away from a surface when moving down a slope. Often, this is not an intended behaviour so to counter this, [Rigidbody2D.SlideMovement.surfaceAnchor](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/surfaceanchor.md) can be used to specify, during each iteration, the direction and distance the slide iteration should look for a surface. Using this, the slide can stay permanently "anchored" to a surface, even if the velocity is moving it away. If this behaviour is not required then the [Rigidbody2D.SlideMovement.surfaceAnchor](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/surfaceanchor.md) can be set to [Vector2.zero](/engine/6000.3/script-reference/unityengine/vector2/zero.md).

The slide behavior will occur using multiple iterations until one of two conditions are met:

* The maximum number of iterations controlled by [Rigidbody2D.SlideMovement.maxIterations](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/maxiterations.md) has been reached.
* The reamining distance has reached zero (as defined by the magnitude of the `velocity` (speed) over the `deltaTime` specified).

When the slide movement is complete as defined above, any gravity behaviour requested will be handled if the provided [Rigidbody2D.SlideMovement.gravity](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/gravity.md) vector has a megnitude greater than zero. In this case, the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) is moved by the [Rigidbody2D.SlideMovement.gravity](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/gravity.md) scaled by the `deltaTime` specified. If the gravity movement causes a contact to be found, the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) is moved to that position.

After this initial gravity movement,  another slide iteration may occur in an attempt to use all the remaining gravity movement. This extra gravity slide iteration (slippage) will only occur if the following conditions are all met:

* The contact is a surface whose slope angle is less than the slip angle defined by [Rigidbody2D.SlideMovement.gravitySlipAngle](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/gravityslipangle.md).
* No initial `velocity` is specified i.e. no slip if movement is requested so slippage doesn't counter that movement.

In summary, calling the slide method using gravity will result in the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) moving with gravity but if no `velocity` is specified, the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) will slide/slip according to the surface slope threshold specified by surfaceSlipAngle.

When the previously described behaviour is complete, a new [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) position has been calculated however, the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) hasn't actually been moved at this stage. It is here that the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) can be instantly positioned at the new position or the move can be deferred using [Rigidbody2D.MovePosition](/engine/6000.3/script-reference/unityengine/rigidbody2d/moveposition.md). This is controlled with [Rigidbody2D.SlideMovement.useSimulationMove](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/usesimulationmove.md). When this is enabled, [Rigidbody2D.MovePosition](/engine/6000.3/script-reference/unityengine/rigidbody2d/moveposition.md) is used whereas when disabled, the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) is instantly set at its new position. It should be noted that both the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) and the [Transform](/engine/6000.3/script-reference/unityengine/transform.md) will be updated when [Rigidbody2D.SlideMovement.useSimulationMove](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/usesimulationmove.md) is disabled and that any [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) interpolation continues to work as expected.

The remaining  configuration options allow more detailed control over the the slide functionality. These are:

* [Rigidbody2D.SlideMovement.startPosition](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/startposition.md) can be used to override the start position of the slide, overriding the current [Rigidbody2D.position](/engine/6000.3/script-reference/unityengine/rigidbody2d/position.md).
* [Rigidbody2D.SlideMovement.layerMask](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/layermask.md) can be used to override which [Collider2D](/engine/6000.3/script-reference/unityengine/collider2d.md) are detected.
* [Rigidbody2D.SlideMovement.useAttachedTriggers](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/useattachedtriggers.md) can be used to select whether any [Collider2D](/engine/6000.3/script-reference/unityengine/collider2d.md) attached to this [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) (that are configured as a trigger) are used to detect contacts.
* [Rigidbody2D.SlideMovement.selectedCollider](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement/selectedcollider.md) can be used to select a specific [Collider2D](/engine/6000.3/script-reference/unityengine/collider2d.md) attached to this [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) to be used to detect contacts. If this is selected, the useTriggers is ignored.

**Note:** The slide method can be used on any [RigidbodyType2D](/engine/6000.3/script-reference/unityengine/rigidbodytype2d.md) but is mainly intended for use when the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) is Kinematic. No body type will interfere with the slide method but using a Dynamic mode might produce unexpected results because such a [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) can have their own gravity, forces, collision-response etc. There is no performance penalty in using any body type, Kinematic, Static or Dynamic and all are valid if required. The Dynamic body type simply requires careful configuration so that its inherent features don't cause conflicting and unexpected movement behaviour.

The following code uses a simple left/right keyboard input to set the relative velocity left or right. The slide method will slide the [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) using the configuration specified in the [Rigidbody2D.SlideMovement](/engine/6000.3/script-reference/unityengine/rigidbody2d/slidemovement.md) and return the results of the slide in [Rigidbody2D.SlideResults](/engine/6000.3/script-reference/unityengine/rigidbody2d/slideresults.md):

### Examples

```csharp
using UnityEngine;

public class Example : MonoBehaviour
{
    public Rigidbody2D.SlideMovement SlideMovement = new Rigidbody2D.SlideMovement();
    public Rigidbody2D.SlideResults SlideResults;

    public float HorizontalSpeed = 2f;

    private Rigidbody2D m_Rigidbody;

    void Start()
    {
        m_Rigidbody = GetComponent<Rigidbody2D>();
   }

    void Update()
    {
        // Calculate the horizontal velocity from keyboard input.
        var horizontalInput = (Input.GetKey(KeyCode.LeftArrow) ? -1 : 0f) + (Input.GetKey(KeyCode.RightArrow) ? 1f : 0f);
        var velocity = new Vector2(horizontalInput * HorizontalSpeed, 0f);

        // Slide the rigidbody.
        SlideResults = m_Rigidbody.Slide(velocity, Time.deltaTime, SlideMovement);
    }
}
```