Introduction to Vite
Unreal Engine Vite is built for professional game development and supports titles currently in active production. Its long-term goal is a continuously evolving modern engine that delivers CPU and rendering throughput competitive with proprietary in-house engines, with ongoing performance, stability and graphics-pipeline work aimed at contemporary console hardware.
The objective is specific enough to be falsifiable: beat Epic's UE5 on fidelity per millisecond and on simulation scale, and be competitive with the proprietary AAA engines on both. Fidelity per millisecond is what Performance Targets and UE4 versus UE5 Cost Analysis measure. Simulation scale is what the physics and character benchmarks measure. Where Vite does not currently win, this manual says so.
The design argument
Epic's 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, Temporal Super Resolution and Chaos. That is what shipped titles on the engine demonstrate in practice.
The virtualized approach — virtualized geometry, shadows and textures, plus reconstructed resolution — adds processing, streaming and memory overhead. Temporal reconstruction, denoising and stochastic sampling introduce noise, ghosting, instability and blur. Substrate, GPU Scene, RDG, heavier shader models and general feature expansion increase base renderer overhead, shader permutation counts, bytecode size, PSO counts, compilation time and cache sizes relative to UE4. Beyond Chaos, CPU cost grows through heavier scene maintenance, GPU Scene uploads, Lumen updates, Nanite streaming, VSM invalidation, World Partition, and render-thread and RHI workloads.
Meanwhile the hardware is moving the other way. The Nintendo Switch 2 has shipped with an expected seven-to-eight year lifespan. Handhelds substantially less powerful than a PS5 are now a mainstream segment, including Valve's Steam Deck and Steam Machine. Hardware costs are rising under AI demand. Against that backdrop, UE5's performance targets look increasingly misaligned with the machines games actually ship on, and the rendering stack is arguably better suited to film, virtual production and high-end PC than to sustainable long-term game development across mass-market hardware.
Vite takes the opposite position: prioritise high visual fidelity while holding strict frame-time budgets at high native resolutions on console-class hardware.
What Vite is made of
Vite began as a fork of NvRTX 4.27 Caustics, which added DX12, ray tracing and rendering improvements over Epic's standard 4.27 branch, along with DLSS, NVIDIA Reflex, improved denoisers and comprehensive ray tracing support including DDGI-lit ray-traced reflections.
On top of that base:
Epic's UE 4.27 Plus branch is fully merged.
NVIDIA's NvRTX 5.0 branch is merged.
Rendering features from AMD's engine branches are integrated.
More than 300 backports from UE 5.0 through the 5.8 era are in the release branch, with over 1,200 integrated in internal staging branches.
The integration work is done by engine programmers with extensive Unreal Engine source experience, using proper code guards, managed shader permutations, and manual adaptation of each cherry-picked UE5 change to the Vite codebase rather than blind merging.
With PhysX and a combined DDGI plus SSGI lighting pipeline, Vite closely resembles the bespoke Unreal Engine build used for the launch of The Finals.
Headline features
Dynamic DDGI. A noise-free global illumination alternative to Lumen. Higher quality bounce and less light leaking than software Lumen, comparable to hardware Lumen for bounce, and typically around twice the frame rate. DDGI implementations ship in Metro Exodus, Overwatch 2, The Finals, Control, The Witcher 3, Warhammer 40,000: Darktide, DOOM: The Dark Ages, Indiana Jones and the Great Circle, 007 First Light, Ghost of Yotei and Star Wars Outlaws including its Switch 2 version.
Static DDGI. A baked mode with near-instant bake times, higher bounce fidelity than traditional baked lighting and better coverage of moving objects, viable on GPUs without ray tracing support at all.
PhysX 3.4. Stable, commercially proven, and in Vite upgraded to build under newer Clang versions for meaningful compiler optimisation gains. Internal stress tests show Chaos running over five times slower than PhysX in physics-bound scenarios.
RTXDI. A less noisy alternative to MegaLights, in its standalone form rather than the Lumen-integrated version found in UE 5.1 and later NvRTX branches.
Tessellation. Distance- and displacement-driven geometric detail without Nanite's overhead.
Full ray tracing suite. Reflections, ambient occlusion, shadows, skylight, translucency, caustics, direct lighting, per-pixel ray-traced GI and path tracing — the rendering stack Black Myth: Wukong shipped on.
For the complete list, see Release Notes.
Is UE4 not a deprecated codebase?
It is a fair question, and the answer is that Unreal Engine 4 continues to power recent AAA releases: Final Fantasy VII Rebirth (4.26, 2024), Stellar Blade (4.26, 2024), Days Gone Remastered (4.11, 2025), Delta Force (4.22, 2026), Mortal Kombat 1 (4.27, 2023), Mario & Luigi: Brothership (4.26, 2024), Princess Peach: Showtime! (4.26, 2024), Pikmin 4 (4.26, 2023), Square Enix's Dragon Quest VII Reimagined (4.27, 2026) and the upcoming Final Fantasy VII: Revelation (4.27, 2027). All of them ship PhysX.
These productions stay on UE4 to retain specific features and meet fidelity and performance targets. UE4 also continues to receive updates from major studios through the 4.27 Plus branch, and remains a priority for Nintendo platforms.
Vite's plan is to keep upgrading that codebase: optimise core systems, modernise the rendering core, improve the UI and update the toolchains, rather than treat 4.27 as a frozen artifact. See Why NvRTX 4.27 for the technical reasoning behind the base version choice.