I encountered 2 errors, 1 is the Metahuman LOD0/LOD1 being grey but LOD2 is okay but very low quality when I try to edit to remove the clothing and re-assemble her. It looks all good from the editor but when I try to assemble her on Epic setting, she just turned grey. If I use High, her body will be grey as well. I have tried disable Forward Shading but still the same.
Another is the mirror having really bad lines/drag. I have changed my pool size to 30000, since I have 32GB RAM but I’m still getting this… I have changed all the settings for Lumen reflection 2048, Hardware Ray tracing to Global Tracing, Hit lighting for reflections, Ray Traced Translucent Refractions. Even changed the PostProcessVolume to Lumen, Quality 4, Max roughness 1.0, Max Reflection Bounces 8, Max Refraction Bounces 64. Even with Planar Reflection, same issue.
That’s quite a bizarre effect you are getting. Since these are two entirely separated issues, let’s try a few solutions for each one:
For your MetaHuman turning dark at LODs 0 and 1, but working as intended at 2, that sounds like a shader conflict. Checking around the community, the MetaHuman skin shader requires Deferred Rendering, so disabling Forward Shading is key. Since you mentioned already disabling it, please make sure it remains so, and that your project is not set to any mobile rendering mode.
Following the same logic, the skin cache can be running out of capacity for the higher LODs. So, it’s worth testing to increase the “Maximum memory for Compute Skin Cache (MB)” to 1024, or even 2048.
Also, please double check your LOD slots, and confirm that each LOD has their materials properly assigned (re-assemble your MetaHuman, if required).
Now, for the reflection conflict, that looks like anti-aliasing ghosting/bleeding. My first guess would be adjusting the current AA method in your project. So, like in the previous steps, go to Project Settings > Rendering, look for “Anti-Aliasing Method” and test with TAA, TSR, and FXAA (save and apply for each test)
Another thing to test, would be to disable Lumen’s temporal accumulation, to stop it from using past frames. Simply use the cmdlet r.Lumen.Reflections.Temporal 0, then test your scene again. One more thing, I would avoid setting the pool size so close to the RAM limit, as it can create a memory overflow. Try keeping the pool close to your GPU’s VRAM limit.
Thank you for getting back! Confirmed no Forward Shading, and increased my Skin Cache to 2048. I managed to get a LOD3 skin which is coloured so I will take that first.
Weirdly, when I reopened my project, the reflection is not THAT bad. I changed it to TAA as TSR keeps giving me Exceed Memory prompt in red. And I have reduced my pool size to 6000 since I have GPU 8GB.
This is the result, not perfect but at least it’s clear. But my metahuman is not reflecting correctly as there will be loss of some details, including the clothes I put on her:
Hello again! Glad that you were able to make progress!
And no, I don’t think your laptop is not compatible, you would be facing way worse issues if so. This sounds more like Lumen’s own limits with reflections. The feature has a history with them, with many simlar cases across the community.
Now, from your screenshot, you are already using ray tracing, hit reflections, and translucency. So, at least as testing, I would try cmdlet r.Lumen.Reflections.ScreenTraces 0, and check how the reflection works.
Alternatively, there’s always the GPU driver refresh, which I think you have yet to test. Simply use the DDU tool to clear your current install, then get the latest driver set for your GPU. If you are working with nVidia, I suggest using the Studio drivers, instead of the game ready ones.
Finally, if the issue persists, and your scene must have both the mirror and Lumen working, I would suggest trying a different approach, like using Planar Reflection. A bit more taxing on the system, but the results should be better.
Also, I have just updated my nVidia graphic driver, and using Studio drivers.
And really do want to apologise for the multiple screenshots, if only I can send over my project file! But hope you will bear with me, and really appreciate your help!
