The difference between Unreal Engine 4 & 5

Beginners into the games development scene might be overwhelmed by the amount of options to start their dev journey; Lumberyard, Unity, Cry Engine, Unreal Engine 4 or 5, to name a few. Today we’ll look at why UE5 is such a game changer, as well what makes it different from UE4 as why it is a great start for anyone entering the interactive media scene.

Lighting

Compared to the likes of Unity and Unreal Engine 4, the release of Lumen and Nanite is an incredibly effective and straightforward lighting system. In Unreal Engine 5, lighting is dynamic (or real time) by default, meaning baking lighting is a thing of the past. In UE4, a similar feature, raytracing, could be integrated, but only with a powerful enough graphics card and processor. With Lumen, all lighting is automatically real time, and is optimised to run without high end hardware, making beautifully lit environments accessible for nearly everyone.

For example, for ray tracing to work in UE4, at least a 6GB 2060 GPU is recommended - and even then, results generally leave a lot to be desired. In addition to this, ray tracing set up requires a lot of leg work; changing project settings, lighting expertise and manually placed lighting in a scene are only part of the procedure of setting up realistic lighting, making raytracing in UE4 far from functional for games due to the high CPU cost. On the other hand, in UE5, Lumen can operate at full fidelity on as little as the 2018 GeForce 20 range - meaning anyone with a new PC within the past 4 years can use UE5 for raytracing and realtime, hyper realistic lighting.

This means raytracing is now a reality in the majority of game releases, including those for console; this was previously not a feature, with most games requiring prebaked lighting - precomputed, non-interactive lighting - to keep optimisation for older consoles and PCs. However, Lumen computes cheap to run, gorgeous looking shadows and illumination in seconds, allowing a much larger audience of players to access stunning graphics.

“The addition of Nanite and Lumen has removed the majority of time constraints of the older engine; polygon limits and light baking are now a thing of the past.”

CGHero Executive Producer Paul Bannon

One drawback of UE5’s Lumen and Nanite is that they do not work with virtual reality - yet. Lumen is designed to work at a maximum of 60FPS on the very latest hardware, whilst VR headsets require a minimum of 90FPS.Epic has stated they are working towards a solution for this, however this likely won’t be for the foreseeable future.

Automatic Optimisation

Nanite, Lumen’s counterpart, works specifically with meshes to automatically optimise meshes for in-game use. This amazingly makes previous constraints such as polycount and Level of Detail meshes (LODs) obsolete.

Nanite calculates a meshes’ orientation and distance from the camera and reduces the polycount automatically. It also breaks meshes down into triangulated segments, which is then visualised on-demand by the editor, so that only the visible details are rendered. Long story short - if you can’t see it, it isn’t rendered, and the closer you are to a mesh, the higher quality it will be. This allows meshes to essentially be any polycount they need, as in UE5, it does not hinder performance nor your PC’s memory and disk space. This also allows objects to be lit in full detail when working with Lumen.

This is an extraordinarily efficient approach to rendering mesh data, as opposed to UE4, which will render an entire object at any point whenever it is in the engine. Higher polycounts and larger objects, for example, negatively effect performance, and as such LODs and polycounts have historically been huge part of the 3D modelling workflow. However, with Unreal Engine 5’s Nanite, this could eventually become a thing of the past.

One incredible feature of UE5 is the introduction of Temporal Super Resolution, also known as TSR. This is an upsampling system, integrated and turned on by default in the engine, which essentially equates to 4k resolution at 60fps, at the cost of 1040p. This will allow developers to publish their games made in UE5 at extraordinarily high-quality resolutions, without straining on hardware or limiting performance otherwise. This works by masking lower frames with an AI-generated higher resolution image; you can check out the difference in this great demo:https://cdn.knightlab.com/libs/juxtapose/latest/embed/index.html?uid=9a3f0644-c1f0-11eb-b7bf-95443c729a29

User Experience and Interface

Unreal Engine has also had a facelift! UE4’s previous UI, although functional, was definitley beginning to feel a bit “retro”, espeically as it hadn’t been updated since it’s release in 2012. However, ten years later and with UE5’s release, the new editor is smart, sleek and Functions and features are far easier to use; the introduction of a Create tab, more support for plugins (especially Quixel and Substance), a more streamline launcher and an improved content browser system. That said, UE5 is also backwards compatible with UE4 - meaning projects from earlier iterations of the engine can be imported and worked on in UE5!

In addition to this, despite some feature additions and UI shuffling, the majority of tutorials and documentation for UE4 apply to 5, too!

Modelling Tools

Finally, with Unreal Engine’s latest increment, modelling, sculpting and UV unwrap tools have now been added. Although not recommneded to model an entire scene from scatch in-engine (spare the headache use an actual 3D software), Unreal Engine 5’s Modelling Mode allows quick deformation and customisation across a huge variety of transformers and tools. The lattice tool, for example, allows for speedy tweaking of assets, removing the need to create dozens of small variations inside Maya or Blender, for example. This works particularly well with Quixel Megascans, as it allows assets to be made unique in a few seconds.

In addition to modelling, users can also use the Landscape, Foliage, Mesh Paint and Animation modes, as well as a brush editing mode, designed for the Mesh Paint feature.

Overall, if you’re looking to jump into Unreal Engine 5, don’t hold back. Epic Games have blown all expectations for their latest increment out of the park; despite having some very minor drawbacks, overall UE5 runs smoother and looks amazing, with some truly ingenious features being introduced. We seriously recommend checking it out; this is serious cutting edge technology that you will love.