# rate

> The rate at which the system spawns new particles.

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine](/engine/6000.6/script-reference/unityengine.md)
* **Assembly:** UnityEngine.ParticleSystemModule

> **Warning:**
>
> **Deprecated.** rate property is deprecated. Use rateOverTime or rateOverDistance instead.

```csharp
public ParticleSystem.MinMaxCurve rate { get; set; }
```

### Remarks

Additional Resources: [ParticleSystem.MinMaxCurve](/engine/6000.6/script-reference/unityengine/particlesystem/minmaxcurve.md).

### Examples

```csharp
using UnityEngine;

// This example shows setting a constant rate value.
public class ConstantRateExample : MonoBehaviour
{
    ParticleSystem myParticleSystem;
    ParticleSystem.EmissionModule emissionModule;

    void Start()
    {
        // Get the system and the emission module.
        myParticleSystem = GetComponent<ParticleSystem>();
        emissionModule = myParticleSystem.emission;

        GetValue();
        SetValue();
    }

    void GetValue()
    {
        print("The constant value is " + emissionModule.rate.constant);
    }

    void SetValue()
    {
        emissionModule.rate = 10.0f;
    }
}
```

```csharp
using UnityEngine;

// This example shows using 2 constants to drive the rate.
public class TwoConstantsRateExample : MonoBehaviour
{
    ParticleSystem myParticleSystem;
    ParticleSystem.EmissionModule emissionModule;

    void Start()
    {
        // Get the system and the emission module.
        myParticleSystem = GetComponent<ParticleSystem>();
        emissionModule = myParticleSystem.emission;

        GetValue();
        SetValue();
    }

    void GetValue()
    {
        print(string.Format("The constant values are: min {0} max {1}.", emissionModule.rate.constantMin, emissionModule.rate.constantMax));
    }

    void SetValue()
    {
        emissionModule.rate = new ParticleSystem.MinMaxCurve(0.0f, 10.0f);
    }
}
```

```csharp
using UnityEngine;

// This example shows using a curve to drive the rate.
public class CurveRateExample : MonoBehaviour
{
    ParticleSystem myParticleSystem;
    ParticleSystem.EmissionModule emissionModule;

    // We can "scale" the curve with this value. It gets multiplied by the curve.
    public float scalar = 1.0f;

    AnimationCurve ourCurve;

    void Start()
    {
        // Get the system and the emission module.
        myParticleSystem = GetComponent<ParticleSystem>();
        emissionModule = myParticleSystem.emission;

        // A simple linear curve.
        ourCurve = new AnimationCurve();
        ourCurve.AddKey(0.0f, 0.0f);
        ourCurve.AddKey(1.0f, 1.0f);

        // Apply the curve.
        emissionModule.rate = new ParticleSystem.MinMaxCurve(scalar, ourCurve);

        // In 5 seconds we will modify the curve.
        Invoke("ModifyCurve", 5.0f);
    }

    void ModifyCurve()
    {
        // Add a key to the current curve.
        ourCurve.AddKey(0.5f, 0.0f);

        // Apply the changed curve.
        emissionModule.rate = new ParticleSystem.MinMaxCurve(scalar, ourCurve);
    }
}
```

```csharp
using UnityEngine;

// This example shows using 2 curves to drive the rate.
public class TwoCurveRateExample : MonoBehaviour
{
    ParticleSystem myParticleSystem;
    ParticleSystem.EmissionModule emissionModule;

    AnimationCurve ourCurveMin;
    AnimationCurve ourCurveMax;

    // We can "scale" the curves with this value. It gets multiplied by the curves.
    public float scalar = 1.0f;

    void Start()
    {
        // Get the system and the emission module.
        myParticleSystem = GetComponent<ParticleSystem>();
        emissionModule = myParticleSystem.emission;

        // A horizontal straight line at value 1.
        ourCurveMin = new AnimationCurve();
        ourCurveMin.AddKey(0.0f, 1.0f);
        ourCurveMin.AddKey(1.0f, 1.0f);

        // A horizontal straight line at value 0.5.
        ourCurveMax = new AnimationCurve();
        ourCurveMax.AddKey(0.0f, 0.5f);
        ourCurveMax.AddKey(1.0f, 0.5f);

        // Apply the curves.
        emissionModule.rate = new ParticleSystem.MinMaxCurve(scalar, ourCurveMin, ourCurveMax);

        // In 5 seconds we will modify the curve.
        Invoke("ModifyCurve", 5.0f);
    }

    void ModifyCurve()
    {
        // Create a "pinch" point.
        ourCurveMin.AddKey(0.5f, 0.7f);
        ourCurveMax.AddKey(0.5f, 0.6f);

        // Apply the changed curve.
        emissionModule.rate = new ParticleSystem.MinMaxCurve(scalar, ourCurveMin, ourCurveMax);
    }
}
```