Unreal visual quality comparison chart between configs and UE versions

[Miguel1900]

Hi all,

After a lot of tests, published and read posts, I was wanting to publish a comparison chart between the most important features of different Unreal versions and configurations, in order to clarify to others (and even to myself) which systems or UE versions I consider the best ones to achieve the most visual stunning result for ArchViz projects (for other kind of projects, other fields could be considered too). What do you think?

[Arkiras]

This chart isn’t very descriptive. What exactly is bugged about baked lighting and RT reflections in UE5?

[Miguel1900]

Yeah, sorry. I haven’t got a lot of time to ellaborate it extensively.

The bug is this one:

Ray Tracing shadows (and reflections) bugs

NOTE: please, enlarge every image to notice the issues. Dirty ‘whity-sketchy’ artifacts (like tons of little lines) around actors’ edges or borders. More noticeables (but not only) when using lights’ source radius higher than 0: [Captura de pantalla 2023-04-22 12.03.17] The right object is lit, even being in a shadowed area. It seems like an incompatibility between the Megascans master material and the ray traced shadows, so some nodes must be destroying the shadowing: [Captura de pantalla…

(Appart from other UE5 bugs, like this elemental one too, you just shoudln’t use RT shadows nor RT reflections in UE5, if you want to be ‘sure’ you won’t face surprises)

[jblackwell]

I think what you’re doing as a concept is brilliant, Unreal engine gives many solutions to potential lighting problems that aren’t always well-documented. That said, I think this is going to need some solid performance numbers behind it in order to really be useful, alongside what constitutes bugged behavior. RT shadows work great with lumen if you know the command to erase the shadow bug.

As of 5.3, I’d have to say that I think baked GI+lumen reflections is probably the best for image quality, perhaps with SSGI there to supplement lightmaps. That is, however, just me.

[Miguel1900]

Hi @jblackwell ,

Thank you. I was waiting for your reply

Sure, a solid and equal comparison would be great, but I have not the time to do it for the public, so I just try to transmit my inquiries to anyone interested, just in an illustrative way, but, for sure, not mathematically accurate regarding the magnitudes.

RT reflections are buggy as shown in my previous post. I also posted “the solution”, which was raising the max RT roughness to 1, but sacrifying performance, so, that’s not a solution, but a temporal workaround. So it should not be considered (or yes, but decreasing the value I assigned to it in the Performance cell of my chart).

In addition, I don’t think they work well with Lumen (unless something changed in the last version and I didn’t realize), because they don’t reflect the Lumen GI, so the RT reflections are very very poor.

About the option of your proposal, it seems to be promissing, but I have detected (not very deeply tested) that mirror reflections (where it’s more noticeable), won’t reflect the exteriors seen throught windows translucent glasses, while RT reflections will. But Lumen reflections give, in general, a similar result than RT ones, so it could be considered as an alternative soon, yes (as Lumen reflections are now compatible with baked lighting).

Regards!

[jblackwell]

Happy to offer insight if I can

I can really appreciate what you’re saying on time. One of the NVRTX people at nvidia @ed me with a new version of NVRTX for 5.3 to test out, but I haven’t had time to do a real review of it justice, which is what I feel it needs.

Standalone RT reflections in general aren’t very useful anymore. The lack of specular occlusion is a big liability in a lot of scenes, basically giving the same light-leaking that RT reflections looked to resolve to begin with. Now that lumen reflections support lightmass, I don’t think there’s any featureset that RT reflections still uniquely have.