Could Valve add HDR to Half-Life and Portal for example? I’m still unsure why it has to be implemented on a “per game” level, why can’t just the screen do some white-level raising and black-level lowering on all scenes?
I must be misunderstanding how HDR works
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why can’t just the screen do some white-level raising and black-level lowering on all scenes?
That’s essentially what Auto HDR does on Windows and Xbox. However, it’s not a true solution. Sometimes the results look okay, sometimes they’re awful, but it’s never the same as a true HDR implementation.
It’s a situation similar to a movie that’s filmed in 3D versus one that’s converted to 3D. Both are “3D”, but converted ones often have issues with things not looking quite right and it just generally doesn’t work well.
To answer your question, yes, the game needs to be mastered for HDR. That includes shaders, textures, even scene design in some cases. It’s not a trivial thing to just add natively to a game.
It needs to be implemented per-game because of quantization. See, tonemapping operators are reversible, meaning you can feed in a tonemapped image into the inverse tonemapper and get an exact duplicate of the non-tonemapped HDR image. Well…you can provided it hasn’t been 8bit quantization. If it has then there are only 255 possible values, because it throws away everything in between as part of the process, meaning that even once you do the inverse tonemap there still only 255 possible values, only now there is a vast gulf of possible brightness between 254 and 255. As an example, maybe 254 is 300 nits, and 255 is 3000nits. Well that’s going to be noticeable, even more noticeable than the banding when just using SDR.
In order to implement HDR properly it needs to be implemented before quantization.
Okay, thank you. It’s more involved than I thought, it’s not just “more contrast”
There is a great application called Specialk that can add HDR in most DX11 games, not sure if it’s available on Linux though.
Hmmm, could be interesting. But maybe not worth it if it has to be implemented at such a deep level for it to work well
It’s definitely worth it, I use it in all games that support it.
It could be possible. Auto hdr exists on xbox without input from the developer.
Auto HDR is available on Windows too but it’s not proper HDR. Can still look good depending on the scene but lacks the same punch as a true HDR implementation