Unreal Engine Vite Manual

What Vite is for

Unreal Engine 5.7 and 5.8 target roughly 60 FPS at dynamic internal resolutions of 720p–1080p on PlayStation 5 using Lumen, Nanite, Virtual Shadow Maps, TSR and Chaos. That stack buys its fidelity with virtualisation and temporal reconstruction, and pays for it in processing, streaming and memory overhead, in noise, ghosting and blur, and in a renderer whose base cost is high before a project has built anything.

With the Nintendo Switch 2 shipping, handhelds like the Steam Deck established, and hardware costs rising, that trade increasingly does not match the machines games have to run on. Vite takes the opposite position: hold high visual fidelity while keeping strict frame-time budgets and high native resolutions.

The concrete claim is a base performance uplift of up to 2.5x real game FPS against UE 5.7's intended feature set, and it is backed by measurements rather than assertion — see UE4 versus UE5 Cost Analysis and Projects and Demos.

Where to start

Pick the entry point that matches what you are doing right now.

The features Vite is built around

Dynamic DDGI

Ray-traced irradiance probe volumes. Noise-free by construction, fully dynamic, and roughly twice the frame rate of hardware Lumen in comparable scenes. See Dynamic DDGI.

Static DDGI

The same probe representation with near-instant bake times. Higher bounce fidelity than traditional baked lighting and better coverage of moving objects. Viable on GPUs with no ray tracing support at all. See Static DDGI.

Optimised RT reflections

Capable of 4K native 60 FPS on a PS5-class GPU. With DDGI active, reflection rays sample probe irradiance for their secondary bounce rather than returning black. See Ray-Traced Reflections.

UE4-era SSGI

SSGI regressed in quality and performance when UE5 folded it into Lumen, and can no longer run alongside a separate GI solution. In Vite it composes cleanly with DDGI. See SSGI.

PhysX 3.4

Libraries rebuilt for newer Clang versions, Blast support added, and GPU-accelerated particles that run across vendors. Measurably faster than Chaos on the same workload. See PhysX.

Apex Destruction and Cloth

Both were deprecated and then removed in UE5 with no migration path for existing assets. In Vite they keep working. See Destruction and Cloth.

RTXDI

A less noisy alternative to MegaLights, in its standalone form rather than the Lumen-integrated version found in 5.1 and later. See RTXDI.

Tessellation

Distance- and displacement-driven geometric detail: smoother surfaces, better silhouettes and high-frequency detail at runtime without Nanite's overhead. See Tessellation.

Performance targets

Every target below includes ray tracing. Full detail and measurement conditions in Performance Targets.

Manual sections

Getting Started

Installation, toolchain setup, building from source, creating your first project, and migrating an existing project from Unreal Engine 5. See Getting Started.

Engine Overview

Why the fork is based on NvRTX 4.27, what performance targets it is designed around, and where the measurable cost differences between UE4 and UE5 come from. See Engine Overview.

Rendering

Global illumination, ray tracing, shading models, anti-aliasing, upscaling, tessellation, ambient occlusion and colour management. The largest section of the manual, and where most of Vite's divergence from stock 4.27 lives. See Rendering.

Physics

PhysX 3.4 as the shipping physics backend: the fast path, fixed timestep, Apex Destruction, Apex Cloth, Blast, and large-scale instanced rigid bodies. See Physics.

Performance and Optimization

Profiling tools, the engine defaults Vite changes out of the box, shader compilation and PSO behaviour, scalability, and how to strip the engine down for faster iteration. See Performance and Optimization.

Platforms

What each target platform supports, which renderer paths are available, and the hardware Vite is tuned against. See Platforms.

Plugins

Plugins bundled with the engine, and the vetting process for proposing new ones. See Plugins.

Tools and Automation

The ViteSetup.bat assistant, installed engine builds, packaging and distribution scripts, and cache management. See Tools and Automation.

Projects and Demos

Downloadable sample projects and benchmark scenes, with the hardware numbers they were captured on. See Projects and Demos.

Contributing

Coding guidelines, commit and pull request conventions, and the backporting workflow used to bring UE5 changes into the fork. See Contributing.

Reference

Console variable reference, compile-time switches, glossary and FAQ. See Reference.

Community and project links