And I also can’t see any foliage and landscape grass in the raytraced scene in lumen view mode.
I am using following CVARS:
r.RayTracing.Nanite.Mode=1;
r.RayTracing.Culling=0;
r.RayTracing.Geometry.InstancedStaticMesh.Culling=0;
also when i try r.RayTracing.Geometry.LandscapeGrass=1; causes the engine to crash.
Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 1067]
Array index out of bounds: 0 into an array of size 0
i think we all know that instanced static meshes from foliage actors are not well supported in raytracing, atm. i mean… they worked at some point, but were kinda slow to compute the structures required. iirc i did a 1 digit crawl in the past.
i can tell now there are some distance field tracing mechanics at work that can mess with translucent surfaces. and illumination. left to right is an empty shell. glass seperated. and a singular mesh. lit and unlit. the split one doesn’t light correct and the singular one has a bit more occlusion when dark, but lights up nicely.
ofc in both cases you need a lil of opacity to get the front layer aka reflection. you missed that in your screenshots.
and… you really shouldn’t use refractive glass for simple glass panes or props that have multiple materials slots with one being raytraced refractive. it will literally block the interior.
aside from that it looks pretty uncanny and if you do a double layer glass pane for miniscule refraction you waste performance. that’s enough tech art for now. (why did i do that? : )
Thanks for the insight. I hope one day we have full ray traced scene without any issues. Maybe If Epic implements the Mega Geometry tech from Nvidia.
but for time being the good thing is substrate is production ready in 5.7 and the result looks closer to path tracer. and it solved all the reflection issues even 0 opacity looks good.
Is it expected, that High Quality Lumen Translucency is really expensive, especially with a lot of screen space covered by translucency?
RT transparency is cheaper (one third of the cost) in my use case, especially because it’s tweakable via the roughness threshold.
I’m seeing 15ms for Lumen Reflections with a full screen Unlit Modulate material covering the screen. I’d expect modulate to be basically free.
See screenshots, the only difference is the modulate material on screen. This is a super simple scene with little to reflect.
Maybe it’s a bit offtopic, but recently I stumbled upon a “AI shader for Minecraft”:
AI hallucinating hard there because Minecraft is made from 1m3 cubes and that is simply not enough to guide AI reliably, without applying tons of compensation from AI to represent something from real world and it can’t be stable because of that. Hardly usable but kinda fun.
But what if AI post process is trained only to add GI/caustics to the provided realtime input of high detail quality? Is it possible to create similar post process feature for UE5, but this time there will be very detailed objects in unlit scene as input to reliably guide AI, and separately AI can receive position, direction and intensity of all light sources in the scene. Stable and detailed input image without lighting + AI training to light it up realistic way… can it surpass Lumen & realtime path tracing in terms of noise-free GI, rendering speed and caustics support?
mildly interesting. the database halucination is very not it, tho. the temporal instability of the general content is nuts. i would understand something like denoising a low res image. like me walking around in the cycles viewport in blender. it’s authored content. not the halucination of the machine. like… you would have to give the machine a normal rendered scene with full pathtracing and tag every polygon or be it a pixel with a texture prompt. but it’s gotta do it stable. not this blurry halucinating database mess that is ai.
afaik additive and modulate use the blending hardware aka rop units. every surface has to go thru that and does a comparison and their math with the framebuffer. this is kinda memory bandwidth intensive reading and writing to the framebuffer. in raytracing you can carry the information as a ray payload, accumulate color and blend along the ray with mutliple hits. the only framebuffer write that should occur is at the end.
if you go nuts and throw random traversal rays and surface shaders into the mix (like refraction and mirrors) it can become quite slow if you push it too hard. roughness requires temporal coordination for random samples aswell. yeh. those are the motion vectors you have no access to and it tends to break up a lil bit. it’s pretty good for clean glass tho with a bit of surface roughness fakery. yes
Hi, I have some really bad looking black artifacts when moving fast in penumbra. The default project’s skylight is casting the shadows. It’s the non-rt lumen, same issue both in the normal 5.6 engine and in the rtx branch. Enabling RTXDI indirect lighting solved the issue. Would anyone know which settings i should look into to make it work without RTXDI?
Here’s a screencapture of the issue:
why are you jittering the camera like an idiot? excuse me. if you play cinematic games you’ll most likely never have this kinda motion. if you play fast competitive you have your settings down to mobile rendering for fps and lumen is likely disabled.
i do not get your complaint. and… every rendering engine uses some form of temporal data these days, that needs a couple frames to warm up. it is what it is.
you’re a new (ab)user and likely a bot, anyway. i don’t think we take this shallow “critique”, seriously. sry.
Otherwise, the lighting is great; I like the results, especially over distances: the attenuation is very lifelike. Small details in the displaced landscape do cast shadows, self-occlude & that all does a lot to add to the overall lighting profile. It’s truly great work; everything is pixel-perfect:
The grass shadows off the hill-crest still show divisions between the blades..
Plus on a aged-10yo-machine, it runs well-enough to be playable even with ridiculous demands made of the system. Everything here is jacked up in terms of density of grass, 2x lumen final-gather/update-speed/etc quality, and even then it’s comfortably-cruising at a steady 50ish-fps.. The rewrite gave me a personal performance-boost of ~25ish% which is ridiculous by any means. As well, the popping usually evident on much-grass is virtually-gone. DLSS still offers a superior picture, but it doesn’t really offer a performance-boost, or even much of one anymore, so there’s parity for me in that area at least.
First and foremost, I’m not a bot, just someone who has recently moved to Unreal Engine. Since even after checking the documentation I couldn’t find which TAA settings to tweak to help mitigate this issue, I turned to the forum directly.
Instead of calling me an idiot simply because I use a mouse instead of a controller, you should recognize that having huge black spots appear is not intended behavior. This happens even without “jerking” the camera, the exaggerated movement in the video was only meant to make the problem more obvious.
Also, since when does a good-looking game automatically become “cinematic” the moment you add fast camera movement? With Lumen I’m getting 100+ FPS on an old RTX 3080, so there’s no reason to use mobile settings as you suggested.
If anything, this should be a discussion about which settings can realistically improve the issue, not about dismissing valid feedback with insults.
sry then. not a bot username. this is not about controller input either. just that in a “normal” (not sweaty) gameplay session you would likely not see the issue that much. erratic motion will only destabilize it more. it’s not a proof. it’s likely a disocclusion artefact. the data for the gi and lighting doesn’t exist at this point in time. this will present itself as a “smearing” trail or in tight corners and fast random motion history it may aswell present itself as black spots. it’s kinda “normal”. screenspace and temporal effects have limited “vision”. if it wasn’t there the last frame it will have to recompute over time. the rng of temporal samples can hit points where at certain times pixels are never hit to recompute the lighting. it is what it is.
I guess you shouldn’t have any camera haptics at all … no camera shaking! … the gaslighting is real bro. Just wow. After 20 years as an unreal engine engineer (Sr and now Lead), it saddens me to see the hostility newcomers are being met with when coming to an engine that epic themselves is pushing into a very “wide” professional space. I’m pretty sure they’d be proud to see new comers met with such hostility…. sheesh.
At the end of the day people are already here asking for help… insulting them simply stomps on an already humble position they are approach the forums with…. A little humility and empathy goes a long way.
can we stop roasting each other here? this is not very productive.
too offtopic
excuse me that i considered the narrative out there on youtube. the likes of threat interactive and company, that constantly complain about unreal and indoctrine other people with those negative views. the post looked like a spin on that. fresh generic username. erratic and forceful demonstration of a glitch that is easily explained if you know a bit about the tech. mention of “competitive” rtxdi tech branch, which an engine newcomer probably wouldn’t or shouldn’t know or consider. the second post jumps to the “conclussion” it’s a TAA artefact (albeit me mentioning temporal things), which it is likely not. there’s more temporal stuff than antialiasing in ue5. it all smells a lil cut and fishy. you get me thoughts?!?
Meaning it’s somewhat expected? 15ms Lumen Reflections for a full screen modulate material vs less than 5ms for a more complex scene? I don’t even care about Lumen Reflections on that surface
I looked through the shader code a bit and can’t find special handling of modulate/additive in the Lumen.
I’ve tried a few tricks like setting WPO with a RayTracingQualitySwitch to move the object our of view during RayTracing but cost stays the same.
Also can’t get regular tranlucency (which is cheaper) not really match the modulate look/behavior.
We use it for tinted glass where we don’t really want reflections or anything on glass. Modulate was always easy and cheap
