OpenXR Loading Screens

For apps targeting head-mounted displays (HMDs), you can use a texture as a loading screen to ease transitions between levels. At the end of this guide, you will be familiar with the Blueprint nodes used for loading screens and will know how to use them within your project.

Set Loading Screen Node

The loading screen must be defined before you can display it in the HMD.

On the Set Loading Screen node, you can select the texture that you want to use for the loading screen from the Texture pin's Select Asset dropdown.

Then, change the Offset vector to specify the texture's position relative to the position of the HMD.

Show and Hide Loading Screen Nodes

Once the Set Loading Screen node has been created, connect its output pin to the Show Loading Screen node's execution pin to display it in the HMD.

When you want the loading screen to no longer display, you can connect it to the Hide Loading Screen node's execution pin.

Using Loading Screen Nodes

In the following example, a map is loaded using Level Streaming as the map transition.

Follow these general steps to add a loading screen to your project:

1. In the Unreal Editor, open your Map in the Level Editor.

2. Click Blueprints > Open Level Blueprint.

   

3. In the Event Graph, add the following nodes:

   • Delay
   • Set Loading Screen
   • Show Loading Screen
   • Load Stream Level
   • Hide Loading Screen
   

4. Connect the output pin from the Event BeginPlay node to the input of the Set Loading Screen node.

5. On the Set Loading Screen node:
   1. Select a texture from the Texture dropdown.
   2. Set the Scale 2D vector to (1.0, 1.0) — a nonzero value — to see the texture.
   3. Set the Offset 3D vector for the loading screen to (1.0, 0.0, 0.5). The loading screen should appear in front of you within the HMD, but this position can be different depending on your headset.
   

6. Connect the output pin of the Set Loading Screen node to the input of the Show Loading Screen node.

   

7. Connect the output of the Show Loading Screen node to the input of the Delay node. The delay node will set a specific time duration for the loading screen to display.

8. Set the Delay node's Duration parameter to 3.0 seconds to make the loading screen display for at least three seconds when you launch the app.

   

9. Connect the output pin from the Delay node to the input of the Load Stream Level node.

10. On the Load Stream Level node:

    1. Set the Level Name parameter to a different Level in your project.
    2. Enable Make Visible After Load.
    3. Enable Should Block on Load.
    

11. Connect the output pin of the Load Stream Level node to the input of the Hide Loading Screen node. Placing the Hide Loading Screen node after the Load Stream Level node ensures that the Level has finished loading before being displayed.

    
12. Launch the Level on your HMD to see the loading screen appear as the Level changes.