# Virtual Background (/en/realtime-media/rtc/build/apply-video-effects/virtual-background/unreal)

> For AI agents: see the complete documentation index at [llms.txt](/llms.txt).

Virtual Background enables users to blur their background, or replace it with a solid color or an image. This feature is applicable to use-cases such as online conferences, online classes, and live streaming. It helps protect personal privacy and reduces audience distraction.

      
  
      
  
      
  
      
  
      
  
      
  
      
  
      
  
      
  
      
  
      
## Understand the tech

Virtual Background offers the following options:

| Feature                                 | Example                                                                                                                                                                                                                                                                                                               |
| --------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Blurred background and image background | ![image](https://assets-docs.agora.io/images/extensions-marketplace/blurred-background.jpg)                                                                                                                                                                                                                           |
| Video/Animated background               | <video src="https://assets-docs.agora.io/images/extensions-marketplace/virtual-background.mp4" poster="https://web-cdn.agora.io/docs-files/1654571689670" width="100%" height="auto">Your browser does not support the `video` element.</video>                                                                       |
| Portrait-in-picture                     | ![portrait-in-picture](https://assets-docs.agora.io/images/extensions-marketplace/portrait-in-picture.jpg) Allows the presenter to use slides as the virtual background while superimposing their video. The effect is similar to a weather news cast on television, preventing interruptions during a layout toggle. |

Want to test Virtual Background? Try the <a href="https://webdemo.agora.io/virtualBackground/index.html">online demo</a>.

## Prerequisites

Ensure that you have implemented the [SDK quickstart](/en/realtime-media/rtc/get-started-sdk) in your project.

## Implement virtual background

This section shows you how to add a virtual background to the local video.

### Set a blurred background

To blur the video background, use the following code:

```cpp
void UMyUserWidget::SetBackgroundBlur(VirtualBackgroundSource& virtualBackgroundSource)
{
    VirtualBackgroundSource virtualBackgroundSource;
    SegmentationProperty segmentationProperty;

    // Set background blur
    virtualBackgroundSource.background_source_type = VirtualBackgroundSource::BACKGROUND_BLUR;
    virtualBackgroundSource.blur_degree = VirtualBackgroundSource::BACKGROUND_BLUR_DEGREE::BLUR_DEGREE_HIGH;

    // Set processing properties for background
    segmentationProperty.modelType = SegmentationProperty::SEG_MODEL_AI;
    segmentationProperty.greenCapacity = 0.5F;

    // Enable virtual background
    agoraEngine->enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty);
    UE_LOG(LogTemp, Log, TEXT("Blur background enabled"));
}
```

### Set a color background

To apply a solid color as the virtual background, use a hexadecimal color code. For example, `0x0000FF` for blue:

```cpp
void UMyUserWidget::SetBackgroundColor(VirtualBackgroundSource& virtualBackgroundSource)
{
    VirtualBackgroundSource virtualBackgroundSource;
    SegmentationProperty segmentationProperty;

    // Set a solid background color
    virtualBackgroundSource.background_source_type = VirtualBackgroundSource::BACKGROUND_COLOR;
    virtualBackgroundSource.color = 0x0000FF;

    // Set processing properties for background
    segmentationProperty.modelType = SegmentationProperty::SEG_MODEL_AI;
    segmentationProperty.greenCapacity = 0.5F;

    // Enable virtual background
    agoraEngine->enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty);
    UE_LOG(LogTemp, Log, TEXT("Color background enabled"));
}
```

### Set an image background

To set a custom image as the virtual background, specify the absolute path to the image file.

```cpp
void UMyUserWidget::SetBackgroundImage(VirtualBackgroundSource& virtualBackgroundSource)
{
    VirtualBackgroundSource virtualBackgroundSource;
    SegmentationProperty segmentationProperty;

    // Set a background image
    virtualBackgroundSource.background_source_type = VirtualBackgroundSource::BACKGROUND_IMG;
    virtualBackgroundSource.source = "<absolute path to an image file>";

    // Set processing properties for background
    segmentationProperty.modelType = SegmentationProperty::SEG_MODEL_AI;
    segmentationProperty.greenCapacity = 0.5F;

    // Enable virtual background
    agoraEngine->enableVirtualBackground(true, virtualBackgroundSource, segmentationProperty);
    UE_LOG(LogTemp, Log, TEXT("Image background enabled"));
}
```

### Reset the background

To disable the virtual background and revert to the original video state, use the following code:

```cpp
void UMyUserWidget::ResetVirtualBackground()
{
    VirtualBackgroundSource virtualBackgroundSource;
    SegmentationProperty segmentationProperty;

    // Reset the background state
    virtualBackgroundSource.background_source_type = VirtualBackgroundSource::BACKGROUND_COLOR;
    virtualBackgroundSource.color = 0xFFFFFF;

    // Set processing properties for background
    segmentationProperty.modelType = SegmentationProperty::SEG_MODEL_AI;
    segmentationProperty.greenCapacity = 0.5F;

    // Disable virtual background
    agoraEngine->enableVirtualBackground(false, virtualBackgroundSource, segmentationProperty);
}
```

## Reference

This section contains content that completes the information in this page, or points you to documentation that explains other aspects of this product.

### API reference

* [`enableVirtualBackground`](https://api-ref.agora.io/en/video-sdk/unreal/4.x/API/class_irtcengine.html#api_irtcengine_enablevirtualbackground)
* [`VirtualBackgroundSource`](https://api-ref.agora.io/en/video-sdk/unreal/4.x/API/class_virtualbackgroundsource.html)
* [`SegmentationProperty`](https://api-ref.agora.io/en/video-sdk/unreal/4.x/API/class_segmentationproperty.html)