I’m on UE5_main relatively often, looking for new features that might be worth compiling a new build over. For the past few months, I’ve been seeing folders and system references for a featureset called Strata: going off of the name itself in addition to the CVars and ChangeLogs, I know it has something to do with material layering and blending.
I’ve read about different BSDFs they’re developing, improving transmittance behavior, layering, and more. For my speculation, it almost seems like Strata will be sort of like the Principled BRDF from Blender: a relatively universal shading model with robust support for different light transport behavior. I also believe it’s meant to act symbiotically with Nanite, although I simply don’t know enough about it to be certain.
What are people’s thoughts? If anyone knows more authoritatively what Strata is and how it works, I would absolutely love to know.
I see, so layered shading models with BSDF evaluation? E.G. that wooden compnent where the gloss material and underlying wood can reflect and transmit light in a holistic and physicalized manner? Where the material can fully evaluate both reflection and transmission?
I found one video on the matter actually on YT. Seems this is is supposed to replace current materials judging by the fact that in the video once strata is enabled old materials are auto-converted to strata.
I see, this really does explain a lot. Essentially, Unreal materials are being updated to the offline industry standard, which really narrows the gap between real-time and offline materials (although how exactly deferred rendering will interact with multi-layer translucency will be an interesting question).
I’ve been pulling down github builds of UE5 for over half a year (almost a full year now perhaps?), and I’ve seen the tech progress immensely. I didn’t try strata except for once where it crashed my computer and caused the engine to behave very strangely, and after that didn’t bother with the migraine. To my understanding, it’s in something like late alpha or early beta, but definitely not feature-complete at this time. Still, I cannot wait to try it out.
That being said, the implementation hump for strata seems much, much higher than Nanite, VSMs, or even Lumen. Unlimited geometry and High-def shadows don’t really change your art pipeline itself that much, GI might require some albedo tweaking and airtight meshes, but asking to remake your entire art pipeline (at least if your team is exclusively real-time), is probably asking a lot. Who knows?
I don’t use ue-main, I’m afraid I would end up constantly updating and compiling just see what’s new, so i’m just occasionally browsing github comments to see what’s being worked on.
Some recent changes seemed to be related to enabling ray tracing on strata, so I wonder if path tracer can even render those materials yet.
Judging from the video, I think once strata is enabled, it also auto converts old materials. While there is some visual difference from the shaders, we should still be able to use standard workflow with how materials are created in terms of image input and most of basic functions.
I was surprised to see a dedicated single layer water there though, would like to see some advanced nested dielectrics.
I wonder if this is supposed to actually replace materials we have currently or if this is some experiment/alternative system.
I generally do much the same actually, I compile a version perhaps once a month but otherwise just follow the comments to know how I can develop content.
I do believe you are correct, HW ray-tracing on Strata seems like an interesting challenge to be sure. I still don’t exactly understand how the system is meant to support deferred shading when translucency and other systems require forward rendering though. Lumen support for multiple lobes along with HW ray-tracing does seem like the newest featureset though, and I’ve only just finished compiling to test it.
From the white papers I’ve read and some people I’ve talked to, the industry does seem to be slowly moving in the direction of real-time path-tracing, and Strata could simply be a way of futureproofing UE5 to support production-level material systems.
Currently testing strata, having issues with screenshots though: Strata materials are giving me similar looks to default in StarterContent, on the path tracer everything is a metallic grey-black, but excellent 60+FPS. Buggy and entirely unusable, but interesting at least.
I don’t actually, my monitor is dual-windowed and I’m trying to crop it with little avail.
And 5.1? To take a casual guess, mirror translucency and translucency on SLW, Support for masked materials and WPO for Nanite (basically everything non-translucent), the potential for the path-tracer to interact directly with full-resolution Nanite items (something with primary rays buried in the github comments), and potentially strata in experimental. Furthermore, I know the SWRT just got a massive refactor, and we’re looking at a 15% speedup or so, so lumen should scale more acceptably to lower=end hardware. Just my thoughts
I do, I believe. The featureset itself confuses me, as I don’t exactly understand the benifits. In areas where you need the highest-quality render, you can of course turn off Nanite, but the VRAM and compute costs of tracing against micropolygon geometry are massive. It may be some sort of way that the path-tracer can access Nanite data without keeping the full mesh on VRAM, but how that would work precisely I couldn’t tell you.
Either way, I think we’re reaching a point where real-time path tracing is viable in select scenes, but geometry needs to be budgeted . I wonder if it will become some sort of trade-off with Nanite, the difference between unlimited geometry and photoreal lighting, or if they’ll figure out how to incorporate the two and all of our lives will get easier.
I want to update on the note of my previous post about ray-tracing against full-res nanite geo: that feature came down from github a handful of days ago, and I’m building a new engine version to test it out. I’m planning on doing a larger post about upcoming 5.1 features just so people can get an idea of what we’re getting. Very excited!
