Intel® XeSS Plugin for Unreal Engine*

Introduction

Intel® X^eSS Plugin for Unreal Engine* integrates Intel® X^eSS 2 technologies into Unreal Engine* (UE). X^eSS Super Resolution (X^eSS-SR), X^eSS Frame Generation (X^eSS-FG) and X^e Low Latency (X^eLL) are parts of X^eSS 2.

For more information, please visit the X^eSS GitHub repository.

Installing the plugin

1. If you use the source code version of UE, you need to build the plugin locally, otherwise skip this step.

• Open the terminal and go to <ue_root_dir>\Engine\Build\BatchFiles
• Run the command line:

RunUAT.bat BuildPlugin -Plugin="<path_to_downloaded_plugin>\XeSS.uplugin" -Package="<path_to_destination_plugin>" -TargetPlatforms=Win64 -VS2019

The last parameter is the version of Visual Studio used to build, required by UE 4 only.

2. Copy (pre-)built files to:

• For UE 4: <ue_root_dir>\Engine\Plugins\Runtime\Intel\XeSS
• For UE 5: <ue_root_dir>\Engine\Plugins\Marketplace\XeSS

Enabling the plugin in the Editor

To enable the X^eSS plugin for a project, go to the plugin selection.

Use the search box to find the X^eSS plugin and make sure it is enabled.

Project settings

Once this plugin is enabled, its default behavior can be modified in the Project Settings menu.

It is possible to disable/enable it in the Editor viewports.

Project packaging

No additional steps are needed for packaging.

Localization support

Localized text is supported via string table "XeSSStringTable", which can be referenced in widgets, Blueprint and C++ code.

Currently these cultures are supported:

Accessing the plugin in a game project

This plugin offers different ways for developers to access the underlying X^eSS 2 functionality.

UE Console Commands

It is more convenient to use for testing during development, not recommended for shipping.

X^eSS-SR

To enable it:

r.XeSS.Enabled 1

To change the Quality Mode:

r.XeSS.Quality <quality_mode>

Where <quality_mode> represents the scale factor:

Auto exposure, which is enabled by default.

r.XeSS.AutoExposure 1

For more details on exposure calculation, please check `Intel® XeSS Developer Guide` in the Documents folder.

X^eSS-FG

To enable it:

r.XeFG.Enabled 1

X^eLL

To enable it:

r.XeLL.Enabled 1

Blueprint API

Blueprint offers the highest level of compatibility and is the recommended way for shipping.

X^eSS-SR Blueprint API

This plugin provides support for querying and settings X^eSS-SR quality modes with Blueprint. It is recommended to use these functions when creating settings menus.

• Is Intel® X^eSS-SR Supported
• Get Supported Intel® X^eSS-SR Quality Modes
• Get Current Intel® X^eSS-SR Quality Mode
• Get Default Intel® X^eSS-SR Quality Mode
• Set Intel® X^eSS-SR Quality Mode

Notes:

1. It is recommend to use the Get Default Intel® X^eSS Quality Mode Blueprint function to set the out-of-the-box X^eSS Quality Mode in the game's UI. Based on the passed Screen Resolution the recommended Quality Mode will be returned - for resolutions with pixel counts corresponding to 1920x1080 and lower it will be Balanced, for higher resolutions it will be Performance.

2. For X^eSS-SR, Blueprint API is recommended to use in Blueprint or C++, for plugin loses control to upscaling screen percentage directly since UE 5.1 and r.ScreenPercentage is set in Blueprint API to keep its backward compatibility.

X^eSS-FG Blueprint API

• Is Intel® X^eSS-FG Supported
• Get Supported Intel® X^eSS-FG Modes
• Get Current Intel® X^eSS-FG Mode
• Set Intel® X^eSS-FG Mode

X^eLL Blueprint API

• Is Intel® X^eLL Supported
• Get Supported Intel® X^eLL Modes
• Set Intel® X^eLL Mode
• Get Current Intel® X^eLL Mode
• Get Flash Indicator Enabled
• Get Game to Render Latency
• Get Game Latency
• Get Render Latency
• Get Simulation Latency
• Get Render Submit Latency
• Get Present Latency
• Get Input Latency
• Get Latency Mark Enabled

C++ API

X^eSS Frame Generation C++ API

Similar to GAverageFPS, GXeFGAverageFPS is offered to display FPS counter in-game, sample code fragment as follows:

#include "XeFGRHI.h"

// Draw the FPS counter.
Canvas->DrawShadowedString(
    X,
    Y,
    *FString::Printf(TEXT("%5.2f FPS"), GXeFGAverageFPS),
    Font,
    FPSColor
);

Debugging

Querying SDK version

Querying feature support on current platform

The support status depends on OS, RHI and Unreal Engine* version. Please check FAQ for more detailed information.

Verifying if a feature is enabled in a running game

The easiest way to confirm that X^eSS-SR or X^eSS-FG are enabled is via:

stat gpu

This will bring up real-time per-frame stats. XeSS or XeFG should be visible as one of the rendering passes.

For X^eSS-FG, a dedicated stat console command is offered:

stat XeFG

You can use it to check average FPS and frame count presented with X^eSS-FG.

Creating frame dumps

Frame dump console variables have been deprecated with X^eSS 2, please use Intel® X^eSS Inspector instead.

Using the High Resolution Screenshot tool

UE provides a console command that allows to take high resolution screen captures:

HighResShot <screen_resolution>

When using this tool while X^eSS-SR is engaged please make sure to set screen_resolution to the currently set output resolution (can be set with r.SetRes <screen_resolution>).

Otherwise, the capture tool will change the target resolution, which will re-initialize the X^eSS context and drop all temporally accumulated data. In result the captured image will not reflect the actual quality seen on the screen.

FAQ

Platforms supported

Currently, only Windows x64 is supported.

Rendering Hardware Interfaces (RHIs) supported

Unreal Engine* versions supported

*) For X^eSS-FG with UE 4.27 and 5.0, 5.1, UE source code patch is required.
   1. Contact your Intel representative to obtain the source code patch.
   2. Apply the patch to the engine source code.
   3. Modify XeSSCommonMacros.h with the following code if it is not defined in your source patch:
    #define XESS_ENGINE_WITH_XEFG_PATCH 1

Relationship between X^eSS-FG and X^eLL

X^eSS-FG requires X^eLL to function. Enabling X^eSS-FG will also enable X^eLL, but disabling X^eSS-FG will not disable X^eLL, which is intentional.

Compatibility with other vendors' frame generation plugins

For X^eSS-SR and X^eLL, there should be no conflict.

For X^eSS-FG, only one plugin could take effect due to swap chain override being required. You can disable it via following options and restart the game to make another plugin work.

1. To set the console variable r.XeFG.OverrideSwapChain to 0 via a ini file. e.g., add the following lines to the Engine.ini file:

[SystemSettings]
r.XeFG.OverrideSwapChain=0

2. Start the game with the command line option -XeFGOverrideSwapChainDisabled.

   Note: Using this command line option will also set the console variable r.XeFG.OverrideSwapChain to 0.

Performance is not as good as expected on Intel discrete GPUs

It could be due to incorrect BIOS settings. Please ensure the following configurations are applied:

• Compatibility Support Module (CSM) or Legacy Mode: Disabled
• UEFI Boot Mode: Enabled
• The following settings must be Enabled (or set to Auto if the Enabled option is unavailable):
  •   Above 4G Decoding
  •   Resizable BAR Support

You can use the Intel® Driver and Support Assistant to verify if Resizable BAR Support is enabled.

Important Note:

Resizable BAR is not the only necessary BIOS setting; all of the above configurations are required. If any are improperly set, it may negatively impact GPU performance.

For more details, visit Intel's Support Article.

FPS drops after enabling X^eSS-FG, what's wrong?

It may happen if you check FPS with stat FPS console command, because X^eSS SDK calls additional Present API, which is not counted by stat FPS.

To check the real FPS number, you could use console command stat XeFG or use Windows Game Bar via pressing Windows logo key + G.

Known issues

• Stereo rendering for VR or split screen usage is currently not supported.
• Pre-built UE 5.1 package doesn't work with 5.1.0, please upgrade to 5.1.1.
• If following link error occurs with pre-built packages, please upgrade Visual Studio to the latest version.

error LNK2019: unresolved external symbol __std_find_trivial_4 referenced in function "int * __cdecl __std_find_trivial<int,char>(int *,int *,char)" (??$__std_find_trivial@HD@@YAPEAHPEAH0D@Z)

• Pre-exposure is still not used in the exposure calculation process.
• X^eSS-SR in Vulkan may not function properly on non-Intel GPUs.
• X^eSS-FG doesn't support Editor yet, please use Standalone mode.
• X^eSS-FG doesn't support fullscreen exclusive mode and will be disabled in that mode.