Hello, I’m getting absolutely terrible light builds, bad reflections and blurry models in my scene. I have static lighting set to 0.1 or 0.01. I have it set to production. I have DirectX 12 set for Windows 10. I have Ray tracing turned on. I have a powerful computer to render. I have everything needed for the level like fog, post process volume, light mass volume, directional light set to stationary. The reflections keeps flickering and stuttering on me. Getting weird artifacts on my models and the edges are blurry. I have light map resolution set to 512 for every model in the scene and it still looks terrible.
Any help would be great, otherwise I’m going to have to use a different engine. alt text
It basically looks ok to me, apart from the flickering, but that may be something else.
The best thing is to start with everything on default and work your way from there. A lot of people get lost in static light tweaking, but there’s an awful lot to learn in that area…
Are you using only screen space reflections? or do you have reflection captures dispersed throughout the scene? SSR itself doesn’t yield the best quality reflections, and on a textured surface like that it would likely blur / pixelate / add noise to the reflections. According to the main tutorial about reflections in the Learning part of the UE4 site, SSR also is the default and takes highest priority over other reflections. So try disabling SSR if it’s enabled, everywhere it can be found, including in objects’ details panels, Project Settings, World Settings, materials, etc. Then put sphere captures in the level, or if there are captures, try tweaking them to be at the same resolution as models / materials and not overlapping too much or having super wide coverage.
For the flickering over at the left in the video, I suggest a Light Propagation Volume set to cover a bit more than the area of the flicker, and set Volumetric Scattering Intensity to lower or 0 if lower doesn’t work. It looks like it’s indirect lighting picking up color and light from nearby and not fully rendering or having difficulty rendering correctly. So, if it’s not scattering as much light, or any light in that small area, then perhaps it’ll stop the flickering / stutter.
It sounds as if ray tracing does supplant screen space reflections with its reflections, and even reflection captures (sphere and box), according to the Real-Time Ray Tracing page in the doc. But if screen space reflections are enabled, they may still be affecting the scene. I found a subtopic that instructs a bit on changing real-time ray tracing settings, including for reflections, shadows, global illumination, LPVs, and more at the following link:
I’m pretty sure it’s not your hardware being incapable of handling it. I use a low-spec laptop (6GB RAM, Intel Core i7 quad core w/ 2.4 GHz and throttling up to 3 GHz, non-full HD display but close, integrated / built-in graphics card Intel 5500U, and Windows 10 Home). From reading I’ve done in the forums and docs, the flickering comes from incoherent settings and can also be a result of improper lightmap resolution settings between objects and lighting. I created a translucent glass material in the 3rd person shooter template, applied it to some of the platforms in there, and there was a flickering artifact across every surface that was adjacent to the surfaces of platforms that I didn’t apply the glass material to…so it could be different combinations of settings / facets that result in flickering. I’ve seen it in a number of different scenarios from reading posts of problems in AnswerHub and the forums.
Thanks for the reply. I increased the static lighting in the world settings to 1, instead of .1 or .01 and it seemed to fix some lighting problems.
Does Ray Tracing mean you don’t need any screen based reflections? Because it’s real time reflections? I have no clue, maybe my 2080 ti can’t handle it and flickers. I’ll try adding in a LPV, but when I add in Sphere Reflections it doesn’t affect my scene because Ray Tracing makes everything reflect already.
Essentially, it comes down to trial and error unless someone knows exactly how to fix it in your specific case. But since you’re using real-time ray tracing, starting with the ray tracing feature settings would be one place to start. I was suggesting light propagation volume use, but according to the ray tracing page, a post process volume would be utilized to change ray tracing features for that specific area of the scene. Btw, the level looks cool so far, and I’m interested to know what it is you’re creating it for.
A side note: I have changed lightmap resolution and it has actually produced changes in dynamic lighting, and sometimes a lower resolution such as 256 vs. 1024 or 2048 is not really that different from those higher resolutions. If the surface the shadow is showing up on (contact surface I think) is a lower resolution or higher resolution than the light and the shadow casting object, then it may produce bad results, even in dynamic lighting situations.
Sphere reflections can also be used to control the number of bounces of indirect light that contain intra-reflections (reflections within reflections). Intra-reflections can cause distortion or black areas on reflective surfaces, so setting a sphere reflection near it and only capturing one bounce can stop any further reflections from entering the surface and screwing things up.
Hello, I’m trying a lot of different setting changes and clicking things on and off on actors and lights and nothing seems to be working. Sphere reflections wont even affect the scene with ray tracing on.
I was working in a level I opened that started with starter content, so a skysphere, skylight, directional light, a couple reflection spheres, a table, chairs, and a small statue on top of the table. I’ve tried numerous changes to settings, enabling and disabling light and shadow settings, and not anything has removed these jittering / flickering artefacts on the metal legs of the table. I think it may be the same effect, or something similar to the artefacts you’re encountering and which are visible in the video you posted. All other reflections and lighting, except maybe one of the chairs that I applied a translucent & refractive material to, don’t have the artefacts. I really don’t understand after trying all those things. Sorry I couldn’t help you. Lots of the issues I’ve encountered in Unreal Engine seem to be steeped in lacking the technical know-how to fix.
The underside of the table maintained artefacts too. It looks like elongated reflections that a distortion of a small part of the reflection image. Like a band of the reflection image is stretched vertically and the pixels are jittering / flickering.
I think I found a fix. In the Post Process Volume, I increase the pixel count and quality of reflections and it seems to smooth it out. But it is really laggy, I might need to buy a Titan or something haha.
You shouldn’t have to increase pixel count and quality of reflections to get rid of a small area of flickering and obvious noise. What’s your system specs? I asked whether AMD supports ray tracing in another thread, and a reply that only NVIDIA cards support it. I work on an Intel Core i7 (5th generation) 5500U, with 2.4 GHz and 3 GHz turbo boost. The display isn’t even full HD, or 1080p, and I tried enabling ray tracing settings in the global post process volume and noticed differences and changes as I was changing them.
It might be ray tracing has not a thing to do with it…probably so. The reflections in the scene in your video aren’t ultra-detailed as far as different types of reflections and reflections within reflections, so I don’t see how that would be a part of the cause. That’s why I described the simple scene I had from creating a new project, and which contained similar / same artefacts on a part of the table. There’s something in the settings or in the code, or possibly in the surface normal data that is not computing right. Did you use any blueprints, other than for materials, to generate the scene?
That’s more than enough to run Unreal Engine, at least based on the suggested specs in the web site. It could be the memory allocation though, or processor threading is strictly using a single core / thread. Sometimes a computer’s system settings or device drivers default to utilizing only what is ‘perceived’ to be necessary.
It’d probably only be a setting in a plugin for Unreal, or in the console, as far as Unreal goes. Outside of Unreal, there’s ways of doing it, but I’m not familiar with them. I simply saw a blurb about it online somewhere which was how to do it, but I didn’t follow the link for reading it because I was doing something else. I came across another piece of Unreal information though that has to do with a common cause of flickering and how to get rid of it. There’s a visualizer called “Out of Bound Pixels” in the Show button in the Viewport. So click Show (next to Lit and Perspective in default viewport UI) > Visualize > Out of Bounds Pixels. Here’s a link to the page for it:
It occurs with lights too, so perhaps the bounding box of the light is smaller than the light’s total radius or distance coverage. Increase the bounding box until it is a bit larger than the object’s actual shape & size, and it’ll include all pixels in the object for rendering.
Hopefully a Unreal 4 staff member can answer the thread and help us. I never had issues in the past until I tried using Ray Tracing.