Tech Reviews

Unreal 4.25

Over the past six weeks, I have been involved with a fellowship program at Epic Games to do a deep dive into Unreal Engine 4.25 and better understand its important role as a tool for pre-production, production and post-production. And with that comes reviews of not only Unreal Engine 4.25, but a handful of tools that extend the functionality.

But first, let’s start with the base software: Unreal Engine 4.25 — as of this writing 4.25.1.

The big news about the latest release of Unreal Engine has to be the support for real-time ray-tracing, which is bolstered by the RTX technology in the Nvidia cards. Now, “real-time” is a factor of the complexity of the scene, its materials and its post-processes. You can quickly take down the scene to sub-24 fps if you aren’t cognizant of the variables. But, when set up properly, you have proper soft shadows, reflections and refractions — without a need to bake lighting — in real time. This delivers a level of realism that has been a hurdle for quite some time. And now that the hardware is readily available, the software is rising to fill that potential.

This realism ties directly into the rise of actually shooting LCD screens in camera as backgrounds behind actors — not only providing a virtual set extension, but contributing to lighting and reflections on the actors and props. The results speak for themselves, being a key part of the production workflow in The Mandalorian series. And it’s not just larger productions that are using them: a whole subculture of filmmakers are beginning to put together homegrown systems. Epic Games is supporting the movement effectively by creating tools to tether the VCam (virtual camera) to be driven by an iPad, or facial motion-capture feeding character performances in real time through your iPhone.

Niagara has been upgraded to a production-ready particle system after living in an experimental stage and then beta for quite a while. Its UI has been overhauled with a birds-eye view of the system and a consistent, color-coded system for clarity. The particle systems live in containers at this level, but functions can be clicked on to dive deeper into a Blueprint-style node graph. But the deeper change has been within the particles themselves and the attributes. This is nothing new to Houdini users as particle attributes are fundamental to controlling complex particle systems.

Also upgraded to “production-ready” in 4.25 is the Chaos Destruction system, which is Unreal’s flavor of dynamics. It supports general collisions and dynamics, but in addition, you have destruction and fracturing, cloth and hair, ragdolls and all kinds of physics goodness. All of which is accessible through Blueprints for customization.

To go along with the ray-tracing features, the new shader systems are available like thin transparency, anisotropic features and updates to the clear coat.

But, what is exciting to me as a filmmaker is the ability to put scenes together in Sequencer (Unreal’s equivalent to an Avid or Premiere timeline), and then render out to ultra-high resolutions with motion blur, depth of field and all the bells and whistles, with the bottleneck being the time it takes to the write the frames to disk, rather than the calculation of the frame itself. I’m even planning on testing some actual production shots using Unreal to see what I can and cannot get away with. This release — and this recent fellowship — may have pushed my career into an entirely new vector!

Website: unrealengine.com great. I’d rather buy a set of pre-textured oil barrels for $5 rather than model and texture them myself. But while the Brushify packs do come with some geo, the power is in the toolsets, maps and dynamic shading systems therein.

I was able to layout a hilly forest with blowing trees using the Unreal internal Landscape tools to sculpt the ground. I used the Foliage tool to scatter trees and bushes. But it was the materials in the Forest and Natural Roads pack that let me lay down layers of grass, dirt, puddles and rocks quickly and artistically; either through painting with brushes or controlling things via some curves. And it was the materials that dynamically changed from grass to rock as I changed my landscape after the fact to make some hills higher and more steep. I mean, it’s not akin to sorcery... I do know about how Unreal works with height maps and slope angle to be able to control materials and object distribution. But the Brushify tools are doing everything under the hood, and I don’t have to figure that out. I just create.

Furthermore, because Garth comes from a gaming background, the tools are designed to be agile and lightweight, and exceedingly customizable. And general hurdles have solutions built in — for instance, being able to break up texture tiling over vast areas via layers of different noises and LODs, or using height maps generated from real geographic data (or from