Is it possible to use a Skeletal Mesh generated/packaged elsewhere in a packaged Unreal game at runtime?

Development Asset Creation
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Hi everyone,

I’m working on a project where an external system (AI service) generates Skeletal Mesh assets and uploads them to AWS S3.
In my packaged Unreal Engine 5.5 game, the user can download those assets at runtime.

:gear: Important note:
I already know how to mount and use .pak files that I’ve created myself (with proper mount points). That part works fine.

However, my real question is about assets generated and packaged externally — outside of my game build or editor.

Specifically:

  1. Is it technically feasible to take a Skeletal Mesh produced elsewhere and wrap it into a valid .pak (including mount point and cooked data) so that a packaged game can mount and use it at runtime?

  2. What engine-level constraints should I expect? For example:

    • Must the asset be cooked for the exact same UE version/platform/target?

    • Will Asset Registry or dependency mismatches prevent it from being recognized or loaded?

  3. Are there security or OS/antivirus restrictions when downloading and mounting .pak or .uasset files from unknown sources? Could they be blocked or flagged?

  4. If this approach isn’t practical or secure, what are the recommended alternatives for using externally generated Skeletal Meshes in a packaged game?

For example, I’ve heard that some projects instead export Skeletal Meshes as FBX or glTF and then import or reconstruct them at runtime using a custom importer or runtime mesh pipeline.
This seems to be a more flexible and secure solution, since it avoids direct dependency on Unreal’s cooked asset format.

:backhand_index_pointing_right: Are there any official references, sample projects, or documentation that explain how to import or build Skeletal Meshes from FBX/glTF data at runtime?
I’d really appreciate any links or guidance related to that approach.

Engine: Unreal Engine 5.5
Target platform: (e.g., Windows)

Thanks in advance for your insights and references!

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There is no OS or antivirus problem.

However, the “cooking” process that Unreal runs to generate the runtime assets, is part of the editor code, which is not licensed to be included in the game itself.

Probably the simplest thing to do would be to use the editor version of your game in a script to “cook” each generated asset after it’s finished generating, and then point the running game at those cooked assets. You’re going to need some process that knows how to take the generation output URL and forward it to the client anyway, so you might be able to hook the automated cooking into that process.

There are other approaches you can take, too. For example, you could write your own skinning code, and render the skeletal mesh as procedural geometry. That sounds like more work for less capability, though!

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