DerivedDataCache

Development Platform & Builds
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Installed Build Editor compiles shaders again despite Compressed.ddp being present

Hi,
I’m preparing an Installed Build of my project and trying to ensure the editor runs without recompiling shaders, by using a pre-generated Compressed.ddp file.

Here is a summary of the steps I’ve taken:

What I’ve done so far:

  • The project is built using an Installed Build (no launcher).
  • I generated the Compressed.ddp using the following command:
UnrealEditor-Cmd.exe .\MyProject\MyProject.uproject -run=DerivedDataCache -fill -DDC=CreateInstalledProjectPak -TargetPlatform=Windows
  • The generated .ddp file is over 1.5 GB, and when launching the Installed Build editor, the log shows:
Opened pak cache for reading. (1515 MiB)

  • I’ve removed unnecessary folders and platforms from the Installed Build:

    • Deleted Saved, Intermediate, DerivedDataCache (except the .ddp file).
    • Removed unused platform folders such as XboxOne, PS4, etc.
    • Kept only Compressed.ddp in MyProject/DerivedDataCache.

The issue:

Despite the .ddp being mounted and loaded, the Installed Build editor still triggers shader recompilation when launching.

For example, I see this in the logs:

[2025.05.27-11.27.41:281][  0]LogMaterial: Display: Missing cached shadermap for WorldGridMaterial in PCD3D_SM6, Default, SM6, Editor (DDC key hash: 727dd9b4e74950cd904de81b8e62eeae94317b10), compiling. Is special engine material.
[2025.05.27-11.27.41:374][  0]LogMaterial: Display: Missing cached shadermap for DefaultDeferredDecalMaterial in PCD3D_SM6, Default, SM6, Editor (DDC key hash: 61e2113121d6c37d15870e4858c761d5d8d7423c), compiling. 
[2025.05.27-11.27.41:425][  0]LogMaterial: Display: Missing cached shadermap for DefaultLightFunctionMaterial in PCD3D_SM6, Default, SM6, Editor (DDC key hash: 27dd6fadaa50c115acabea7dd0fb596336ae573d), compiling.

Additionally, ShaderCompilerWorker processes are launched and runtime shader compilation occurs, which I hoped to avoid using the .ddp cache.

Additional Context:

  • The editor is launched with the -installed argument.
  • The file Engine/Build/InstalledEngineBuild.xml is present.

My questions:

  1. What are the common reasons for shader recompilation in an Installed Build even when Compressed.ddp is loaded?

    • Could it be due to incomplete content loading during the -fill run?
    • Or is it a DDC graph configuration issue?
    • Or are there known cases where some shaders (e.g., editor previews) are never cached in .ddp?

  2. Is there a way to inspect or verify what shader/material keys are actually included in the .ddp file?

I’m trying to make sure that the Installed Build editor starts up cleanly without triggering any shader compilation, especially to improve startup time and avoid runtime hitches.

Any guidance or recommended steps to ensure the .ddp is complete would be greatly appreciated.

Thanks!