Migrating from Unreal Engine 5

Moving a project from Unreal Engine 5 down to Vite is a real migration, not a version bump. This page sets out what transfers cleanly, what needs replacing, and in what order to do it.

What transfers, what does not

UE5 feature	Status on Vite	What to do
Static meshes, textures, materials, animations	Transfers	Downgrade with the UE Downgrader plugin
Blueprints	Transfers	Downgrade; re-test node-for-node, some UE5-only nodes have no target
C++ gameplay code	Transfers	Vite backports many UE5 APIs; see below
Gameplay Ability System	Transfers	Vite includes GAS updates backported from UE5
Nanite	No equivalent	Author conventional LODs; use Tessellation for surface detail
Lumen	Replaced	Use DDGI, optionally with SSGI
Virtual Shadow Maps	No equivalent	Cascaded shadow maps, or ray-traced shadows
TSR	Replaced	DLSS, FSR, XeSS, or native with SMAA
MegaLights	Replaced	RTXDI
Chaos physics	Replaced	PhysX
Chaos Destruction	Replaced	Apex Destruction and Blast
Chaos Cloth	Replaced	Apex Cloth
Substrate	No equivalent	Standard material model, plus Callisto BRDF
World Partition	Replaced	World Composition and level streaming
Niagara	Transfers	Available; PopcornFX is a faster alternative
MetaSounds	No equivalent	Sound Cues, or Wwise

Downgrading assets

The UE Downgrader plugin converts assets from UE 5.8 and below back to 4.27 and 4.26. It works by first upgrading assets to its source version(usually latest UE5), then applying patches to the .uasset files so they are readable by the target version, minus the data the older format cannot represent. Nanite data, for instance, is stripped during a 4.27 downgrade.

What the plugin cannot do is invent 4.27 equivalents for features that do not exist there. Nanite on masked materials, new material nodes and new Niagara modules will not survive the trip. Budget for reauthoring those.

The plugin is commercial. Its author, Ciprian Stanciu, is active on the Vite Discord and has provided direct support for several Vite projects. There is a video walkthrough of the workflow.

Migrating code

This is the part that is easier on Vite than on stock 4.27. The fork deliberately backports UE5 API surface so that UE5-era code compiles with fewer changes: updated container classes, game framework updates, and Gameplay Ability System functionality are all present.

You will still hit differences. Work through them in this order:

Physics. Anything touching Chaos namespaces, FChaosScene, geometry collections or Chaos vehicles needs to move to PhysX equivalents. This is usually the largest single chunk of work. See PhysX Overview.
Rendering. Code that queries or drives Lumen, Nanite or VSM console variables has no target. Replace with the Vite equivalents in Rendering.
Core API drift. FVector is double-precision in UE5 (FVector3d) and single-precision in 4.27. Large-world-coordinate assumptions do not hold. Audit any code doing precision-sensitive maths at large world offsets.
Module and build rules. .Build.cs files referencing UE5-only modules need those dependencies removed or replaced.

Recommended migration order

Migrate a UE5 project to Vite

Stand up an empty Vite project first and confirm your toolchain and engine build are healthy. Do not debug two problems at once.
Port the C++ modules with no content. Get them compiling against Vite before any assets move. Check physics and rendering API breakage here.
Downgrade and import a small, representative slice of content — one character, one environment, a handful of materials. Validate that it looks and behaves correctly.
Replace the lighting setup. Lumen has no direct translation; set up DDGI volumes and tune them against the slice you just imported.
Rebuild the physics setup. Re-author destruction with Apex Destruction and cloth with Apex Cloth.
Bulk-migrate the remaining content once the slice is proven.
Profile against your target hardware and set scalability. See Profiling and Benchmarking.

A mixed-version workflow

You do not have to move everyone at once. A common arrangement is for programmers to work in Vite while artists and content creators continue in a stock Epic Games Launcher install of 4.27, with content flowing one way. For that to work, the launcher-side users need the standalone DDGI 1.1.5 plugin so that lighting looks approximately right on their end. This is exactly what we do at Vite Studio, and has work so far with no issues for modeling, animation and sound design work.

Unreal Engine Vite Help