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Comment by wallstop | Hacker News Reader

From my experience with game engines and people that really care about CRTs - I believe the effect (confidence: 95%) can be entirely achieved with rendering glue in any of the modern game engines - Unreal, Unity, Godot, etc. Now, whether or not it is a literal shader, or a shader + custom sauce, not sure.

However, I have not tried, so I cannot verify that claim to 100% accuracy. The author ...might have tried? They definitely surveyed the landscape. My read of the article was that they went down this rabbit hole and back-justified it instead of investing a similar amount of time in a practical solution in a modern engine.

CRT look and feel is a niche full of very passionate and opinionated people.

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I've done a version of this in Godot. It's kind of a hack, but it works and it's all Nodes without needing a script. You could do it more easily in a compositor effect but you have to deal more with the guts of the engine.

The basic idea was to use a chain of Viewports and TextureRects using the previous ViewportTexture to do the effect. This is essentially just setting up a chain of framebuffers that I can draw on top of at each step. The first step just does a simple calculation to convert the incoming color to an "energy" value with a simple shader on the whole frame. Then there are two decay viewports that feed each other to decay the old frame and overlay the new one. These just have a decay parameter that I can tweak to get different effects. There's a final Viewport that supersamples everything because I'm going for more of a vector display look than a CRT. And I can layer on other effects at either the energy state (like decaying phoshpor) or at the final stage (like flicker or screen curve).

Here I've exaggerated the decay quite a bit so you can see the effect. https://www.youtube.com/watch?v=2ZrvcZIfqOI The trails there are entirely from this effect. I'm only rendering the spinning figure. You can also see where lines overlap they are brighter than the surrounding lines because I cap the maximum energy value in the first layer.

Do you have an example? I’ve done a slightly-more-than-casual search for convincing post-processing and haven’t found success. Filters still tend to retain the sharpness of pixel edges in a way that CRTs don’t, and the contrast doesn’t look right either.

I'm not saying the tech currently exists in a form you can just plop into a project and have it give you the exact CRT look and feel that you want. What I am saying is that you can do that within any modern game engine - you just have to decide what, exactly, the look and feel you want is and how to get there.

As an example, I will quote the article:

> Retro Game Engine owns the full frame lifecycle. I decide what the input signals are, what the display does with it, how time affects it, what gets presented and when.

You can replace "Retro Game Engine" in that sentence with "Unity" or "Godot" and it is just as true.

Balatro is a good example. Lots of different opinions on whether its a good CRT effect or not.

Still the best CRT simulation I've seen is in an X screensaver called XAnalogTV. It simulates both CRT artifacts as well as NTSC channel cross-talk and analog interference. It amazes me that still no one has produced a portable version.

I think you are underestimating what a filter is allowed to do.

You could build a simulation of the universe, send the frame data to the CRT inside that universe and capture the output of the simulated CRT and show it on the LCD.

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