D5 2.3 / RTX 3090
I’m currently testing D5, and I bumped into an annoying issue. In some cases , reflections are over bright and seems to reflect the sky instead of what they are supposed to reflect… It apparently comes from the
size of the scenes, and indeedn if elements far away are removed, the reflexions are ok.
This issue was supposed to be fixed in 2.3 but it doesn’t seems to be the case.
Have you any idea when it will be resolved ?
Hi, jeanthiriet!
Did you turn off “Auto Exposure”?
And we will provide a new GI in D5 version 2.4, which will fix this issue entirely, please stay tuned.
Hi Ruby, Thanks for the fast answer.
So, no, it’s not an exposure issue, but a GI/Raytracing issue.
My guess is that you’ll switch to UE5 before the end of the year, and I imagine that your new Lumen Based GI will be working fine then !
By the way, it will be great to have an “advance user” option to stick to regular path tracing, for very precise renders (as the option already exist in UE engine, it will just be a tiny switch to flip).
In my experience this started happening in v2.2 Surfaces started glowing or reflecting light from invisible light sources. Turning auto exposure off only darkened the image but surfaces still glowed unnaturally.
Be sure that flooring has a thickness and is unsmoothed. You can also create a box underneath without upper face. The last thing is to check back faces. 
Thanks for the tips, but all elements are solid groups, no back face here either. It really is an issue with the way GI is calculated.
I guess that, as it’s relying partially on an array of invisble probes to approximate the light, sometime one of them is not in the right place, and it creates this kind of effect.
That’s why, an option to switch to pure pathtracing will be nice, as it eliminates this kind of issues.
I’m having the same kind of issues. Despite the major improvements in the D5 program (and I’m really enjoying it) the way light is calculated, is still not very accurate. Version 2.1 was easier to light up a scene imo. Since 2.2 we’re getting strange reflections, over exposed areas, material issues etc. Hope 2.4 will address and solve these problems. I’ll post a few images and examples in the coming days to illustrate my point. Still I’m very happy with D5, which has a bright future ahead!
Yes, but everything was mostly good in v 2.1
My kitchen scene now glows weirdly from unknown sources of light:
It’s as if every horizontal surface were giving off light.
For what i’m understanding, up until V2.2, D5 was using UE5 pathtracer to calculate the GI, which gives perfect result on a final render, but is slower in realtime, with some noise and artefact when denoised.
In V2.2 They went to an hybrid solution, based on a array of light probe (there is a blog article about that), which is faster, but the en results are nowhere as accurate.
I too hope that UE5 lumen will be in the next revision, or that they’ll offer an option to switch to pure pathtracing during render. I’m considering switching from my current rendering solution to D5, but I’ll wait until this point is resolved.
It is a know bug related to objects far away. @Oliver.J is working on it with the team. Hopefully resolved in the next update.
