How to Maintain Red Color on Emissive Light While Achieving Proper Bloom in UE5.4?

Development Programming & Scripting
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Hello everyone,

I’m working on a project in Unreal Engine 5.4 and trying to create a material for colored emissive lights, such as red taillights on a car. I’ve set the Emissive Color to (1, 0, 0), but this doesn’t produce the desired bloom effect – the material doesn’t look like a proper light source.

To get bloom, I’ve increased the scalar multiplier on the emissive color. However, as I increase the multiplier, the material starts to blow out to white before I reach a suitable amount of bloom (tried scalar values of 1, 10, and 100). While it looks somewhat acceptable in shaded areas, in direct sunlight the material appears washed out, and I lose the rich red color I’m aiming for.

Is there any way to maintain a strong red color on the light source itself while also achieving a good amount of bloom? Ideally, I’m trying to replicate the look seen in other games, like the train lights shown on the right in the attached reference image.

I would greatly appreciate any tips or advice on this issue. Also, I’ve included images showing how the material looks in both shaded and sunlit areas, along with screenshots from the material editor settings I’m using.

Thank you very much for your help!

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You could try turning the tone mapper, see

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Thank you for your response. I tried the suggested adjustments, but the results aren’t quite what I was aiming for…

Following your guidance, I was able to achieve the effect shown as the image (left → middle), but what I’m really looking for is a bright red glow that appears similar to what you see with the human eye in real life (right image, from another game).

Currently, in Unreal Engine 5, it seems challenging to create a truly vivid red glow using Emissive Color or Base Color with pure red [1,0,0] or scaled values of it—at least with my current knowledge.

Specifically, when I set Emissive Color to [1,0,0], the result is a red material, but no bloom effect is applied. If I try scaling the value up to something like 3*[1,0,0] to achieve bloom, the main color shifts towards bright orange. And while increasing it to around 30*[1,0,0] does create the desired bloom, by that point, the core color is almost completely white (as seen in the left image).

On the other hand, in real life, we perceive red light sources in a way closer to the right image, so I’d like to replicate this effect in Unreal Engine as well (for example, car brake lights).

It’s hard to believe that a high-quality engine like Unreal wouldn’t support such a visual effect.

Do you have any suggestions or ideas that might help?

Additionally, while the bloom effect in the Post Process Volume allows for amplifying existing bloom, it doesn’t support increasing bloom from zero or altering the color of the emissive object itself. Therefore, it doesn’t seem applicable in this context.

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From you target picture, you might get some mileage with a custom post process. Or possibly a total fake, when the bloom is actually just a single stationary particle. Something like that.

The problem is the target is not PBR.

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Car brake lights doesn’t look like the image on the right in real life though. Glowing Objects IRL loses saturation as you increase the brightness

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As you can see from the above image, only bright and slightly de-saturated parts of the break lights produce bloom.

Back to the question of maintaining Red Color, like @ClockworkOcean suggested, I would also recommend using a single particle with an additive material to achieve the bloom effect while keeping the brightness of the emissive material low
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