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Question Do you use a dedicated reflection probe to make Metallic objects look good?

Discussion in 'High Definition Render Pipeline' started by dgoyette, Nov 26, 2022.

  1. dgoyette

    dgoyette

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    I've always felt like it wasn't super clear how to make metallic objects look "correct" in a scene. A long time ago, I found that metals only look "correct" if there's a reflection probe active. Otherwise, metals are basically black. For example, the door in this scene without an active reflection probe on the left, and with an active reflection probe on the right:

    upload_2022-11-26_12-47-24.png

    That's generally fine with me, except that in most cases, I don't want reflection probes affecting most of the object in the scene. If everything received lighting from the reflection probes, it gives a very flattened, ambient light look, which I don't like. For example, on the left is just the doors getting reflections, while on the right everything gets reflections:

    upload_2022-11-26_12-50-36.png

    The differences in this specific scene are kind of subtle, but having all objects receive reflections gives distance floors and ceilings a really washed-out look. You can see how much brighter the ceiling is in this scene because of the reflection probe affecting it, and it only gets worse as the distance increases.

    For this reason, in all of my scenes I have a dedicated reflection probe, which I assign to a specific Light Layer, and all metal object renderers enable that light layer. This ensure metal objects look more or less correct, which non-metal objects don't receive reflections. A little cumbersome, but not awful.

    The one big downside is that light layers are per-renderer, not per-material. So if I have an object with some metal and some non-metal, I tend to need to break that into multiple renderers, so that only the metal part(s) get assigned to the light layer the probe affects.

    It occurs to me this feels like kind of a convoluted process, so I was curious how other people managed to get metallic objects to look "correct" in their scenes, if they're doing something similar, or if I've chosen an off approach.
     
  2. Oniros88

    Oniros88

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    If you are using HDRP, in the settings there is an option to force ambient light on metallic objects, so they are "fake" lit without needing reflection probes.
     
  3. dgoyette

    dgoyette

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    Interesting. I'm not 100% sure that's what I'm looking for, but do you know where that setting is controller, and I'll check it out? I just looked through the Quality settings and the HDRP Global Settings, and I didn't see anything that looked like what you described. (I probably just missed it...)
     
  4. Oniros88

    Oniros88

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    It's under the Frame Settings, called "metallic indirect fallback"
     
  5. dgoyette

    dgoyette

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    I see. Thanks. It seems enabling that does brighten metal objects, but they don't quite look like metal. More like plastic. I'm not sure what exactly is missing from them that makes them not look like metal with that setting...

    However, that setting does seem to be the answer for why my metal objects always show up as black in reflection probes, and how I can prevent that. So that's a win. :) Thanks.