'Tonemapping' issues in trailers and gameplay recordings of PoE2
|
Hello,
Since I'm not sure how to contact GGG directly, I've decided to make a feedback post. I understand that this is a niche 'issue', but it needs to be addressed if PoE2 is aiming to be high-quality look-and-feel game. Usually it's referred to as 'tonemapping problems', where bright, colorful objects change hue as they become lighter. This is basically a mathematical problem and if usually solved by using a more robust image formation pipeline. In an ideal scenario, a base colour (let's take blue as an example) should retain it's hue all at the way towards white. Instead, many of the effects in PoE2 seem to experience hue-shifts, where the initial hue of the blue rotates towards cyan and then turns white. This is an error. Usually these rotations happen towards R, G, B, C, M, Y. I could expand in an email if necessary. Examples: Blue-cyan hue shift:  Red-yellow hue shift:  Brown-yellow hue shift:  Blue-cyan hue-shift:  Last edited by DasIstEmpy#7465 on Nov 24, 2024, 4:19:30 PM Last bumped on Dec 3, 2024, 6:14:50 PM
|
|
|
To me those pictures look fine maybe i could judge based on a comparison but i think it might also be dependant on the wanted appearance.
Id like to learn more about this if you are willing to share some details. |
|
" It's 99.999% never the wanted appearance, just something that happens due to poor pixel value handling. The lack of a smooth gradient to white and a rotation towards the primary hues is a tell-tale sign of an 'oopsie' and it is an eye-sore once you start to notice them. Most likely a lot of people in the CGI and the film industries have been taught to notice it and a avoid it like the plague, because it makes the film/game/image feel cheap, broken, and amateur-ish. It's a rather complex issue to explain on the game forums, and I'd like to avoid doxxing myself. |
|
" Interesting post. But I do not see what you are describing at all in your examples. I am sure if the artists and renderers read this they will understand but to my eye I don't see anything that seems out of place. |
|
|
its visible at the boundary between the colour and the fully saturated brightness (white) he is bringing up the issue that the brightness should not cause a color change before it fully saturates. its a thin layer of colour that doesn't fit. once you see it it is bothersome. thanks OP!
|
|
" Correct! Here is a very basic, manually produced example (so the accuracy will be off)  Top line indicates a gradient containing a single hue (single colour if you may), that goes (correctly) from Dark colour, to fully pure colour and lastly to colour at its maximum lightness. The line below it indicates a broken gradient containing shifted hue (that is a result not of an artistic intent, but software being "careless" with colour) Edit: Just to iterate - 'cyan' is not a 'lighter version of blue'! They are both different, very specific hues. Last edited by DasIstEmpy#7465 on Nov 25, 2024, 12:23:56 PM
|
|
|
So, if I understand correctly, you mean to say the color "break-off" point, so to speak, is off? The bleeding white spots? As in, it transitions to white far too quickly?
Gaming PC: Win 11, 7600X3D, RTX 4080, 32GB DDR5-6000 CL30, 7000 MB/s SSD, 850W, 3840x2160p 120Hz
Streaming PC: Win 11, i5-12400, RTX 4060, 32GB DDR5-6000 CL36, 7000 MB/s SSD, 450W, 1920x1080p 60Hz |
|
|
now i know dick all about VFX and CGI, but wouldn't explosions look more natural with an intentional color shift due to thermochromism? You can see that color change is rather abrupt in your
Last edited by AintCare#6513 on Nov 25, 2024, 12:54:25 PM
|
|
" Not quite. The rate of change IS off, but it's only a part of a compound issue. The issue would be you taking a brush, dipping in red paint, dragging it across the canvas and somehow ending up with yellow in one stroke. " You are correct that *some* hue rotation is required (red-towards-orange, etc), otherwise we end up with different perceptual problems. However, that hue rotation MUST be controlled, MUST be subtle and exhibit a steady rate-of-change. What is shown in the screenshots are simply what happens inadvertently when 'tonemapping' is set to 'yolo'. (Or someone simply processed the videos in a careless manner, I have not played PoE2 yet, I've only seen recordings) If you colour-pick the huge explosion 'Brown-yellow' example, you'll find that many of the areas around the centre are completely 'flat yellow', as the values get stuck at R and G channels are stuck at 1.0, but the blue channel is free to change. This induces the hue errors. |
|
" yeah the brown yellow has a very THICC area with that offset. sounds like channels being saturated/clipped. not sure if related but I also saw some flickering in one of the streams after the Q&A, might be temporal artifacts?... maybe they are just working things out |
|
