Usually I render EXR with ACEScg color output. However for a certain workflow where i have to render many different things on a perfect 100% white Background. I found I could leave out any Post-Production and save a bunch of time by rendering to PNG with a slight tone-curve adjustment…well, so I thought.
In reality it’s glitch galore. First I noticed some black pixels flying around. then i zoomed in, and it’s not black, it is a 3-Pixel-Glitch that always has the same pattern. Yellow-Magenta-Cyan
Here you can see that it appears on many places in the white area of my unlit material that makes the BG color.
This happens for Path Tracer and for Deferred rendering.
It only appears on the 8bit formats PNG and JPG. It does not happen on EXR. Tone Curve seems to be involved in this issue. With Tone Curve on at a value of 1 there is nothing there. Lowering the Tone Curve Amount to lower than 1 or deactivating it entirely via the color output is causing these artifacts to appear. Nothing like this in editor btw.
I have already broken it down to the most minimalistic scene: Cube with default material in Front of an Unlit white surface. (Tone Curve disabled) Its everywhere. examine for yourself (Path Tracer rendering) EDIT: Forums image format compression made it very fuzzy and turned it into mid compression JPG
What is going on?!? Also there is this “Black Pixel Border issue” that randomly appears on one of the borders. But I made a seperate thread for that. This is destroying my entire time-saving workflow once again.
This topic has been moved from International to Rendering. Hopefully, this category change will help you to get answers.
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Current Version of UE. 5.4.4
AA Method is set to None. I use something like Spatial 512 Temporal 4 for Pathtracer. When i rendered Deferred I used 16 Spatial and 2 Temporal. Repro steps are correct. I have Tone Curve Amount at 0.85.
Denoiser OFF. Multisample Effects disabled. Motion Blur set to 0. No DOF. No Bloom, No Flares.
You can lower the Tone Curve Amount in PPV or alternatively turn it off via Color Output in MRQ settings. Thats all the settings.
One unusual thing i just noticed is that my Unlit material is set to masked, but opacity is solid 1 (some baggage from the past).
