UnrealEngineUWP/Engine/Source/Programs/Horde/Docs/Tutorials/RemoteShaderCompilation.md

Horde > Getting Started: Remote Shader Compilation

Getting Started: Remote Shader Compilation

Introduction

In addition to remote C++ compilation, Unreal Engine supports compiling shaders remotely on Horde agents. Since shader compilation is highly CPU-intensive, this capability can significantly accelerate the cooking process.

The following steps demonstrate how to configure Horde and Unreal Build Accelerator (UBA) functionality from the command line. Once you've verified that it's working, this same functionality will be available from within the editor as well.

Prerequisites

• Completed the guide described in Getting Started: Remote Compilation
• A Windows workstation
• Lyra sample game for UE 5.5+ installed (instructions)
  • Note that the GitHub version requires additional files to be installed

Steps

1. If building Lyra from source, ensure the editor is built:

   Engine\Build\BatchFiles\RunUBT.bat LyraEditor ShaderCompileWorker Win64 Development -Project=..\..\Samples\Games\Lyra\Lyra.uproject
   

2. Configure Samples\Games\Lyra\Config\DefaultEngine.ini with Horde and UBA settings:

   [UbaController]
   Enabled=true
   Horde=(Pool=Win-UE5,MaxCores=500)
   
   [Horde]
   ServerUrl="http://{{ SERVER_HOST_NAME }}:13340/"
   

   MaxCores=500 describes how many CPU cores this UBA session should try to allocate for work. Adjust as needed for fair use and size of your Horde setup.

3. Cook the data, which will compile shaders among many other asset transformations

   Engine\Binaries\Win64\UnrealEditor-Cmd.exe Samples\Games\Lyra\Lyra.uproject -run=cook -targetplatform=Windows -noshaderddc
   

   The last argument -noshaderddc ensures any shader cache lookups are skipped which is useful during testing or benchmarking UBA.

4. Following the log you should see shader compilation being started with Horde and UBA lines appearing:

   LogUbaHorde: Display: Created Horde bundle for: ../../../Engine/Binaries/Win64/UnrealBuildAccelerator/x64/UbaAgent.exe
   LogUbaHorde: Display: Getting Horde server URL succeeded [URL: http://{{ SERVER_HOST_NAME }}:13340/, Source: Engine INI configuration]
   LogDesktopPlatform: Display: Launching OidcToken... [Engine/Binaries/DotNET/OidcToken/win-x64/OidcToken.exe --HordeUrl="http://{{ SERVER_HOST_NAME }}:13340/" --OutFile="<some-path>" --Unattended=true]
   LogUbaHorde: Display: UBA Horde machine assigned (Linux) [192.168.2.156:7000]: http://{{ SERVER_HOST_NAME }}:13340/lease/670ff187af783212b5c15b6f
   LogUbaHorde: Display: UBA Horde machine assigned (Linux) [192.168.2.247:7000]: http://{{ SERVER_HOST_NAME }}:13340/lease/670ff187542cd63730a0a23b
   LogUbaHorde: Display: UBA Horde machine assigned (Linux) [192.168.2.132:7000]: http://{{ SERVER_HOST_NAME }}:13340/lease/670ff1886673800f993f56ac
   

   This indicates work is being sent to remote Horde agents and you can observe them from Horde server as well.
   
   By default, authentication via OidcToken and a browser is performed the first time a developer triggers use of Horde and UBA. The guide for remote C++ compilation covers this in more detail. When cooking through a Horde job, the -Unattended flag should be passed to avoid triggering any interactive dialogs or blocking UI. Every job includes an environment variable UE_HORDE_TOKEN which, when present, takes precedence over the default interactive authentication method.

5. For debugging and tuning purposes, it can be useful to force remote execution for all compile workloads. To do so, add bForceRemote=true under [UbaController]

Tip: Start UbaVisualizer tool and leave it running. It will automatically attach to new UBA sessions and display an overview of how compilations are scheduled. Located in Engine\Binaries\Win64\UnrealBuildAccelerator\x64\UbaVisualizer.exe.