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Question Weird Light Flickering in HDRP

Discussion in 'High Definition Render Pipeline' started by Suryansh55, Jan 19, 2021.

  1. Suryansh55

    Suryansh55

    Joined:
    Jun 27, 2020
    Posts:
    16
    I am using Unity 2020.2 HDRP 10.2 and I used the lights that came with new sample scene to create a new interior dark scene but I don't know why lights keep having this weird behaviour I even disabled Bloom but it did not help.

     
    Suryansh55, Jan 19, 2021
    #1

  2. Camarent

    Camarent

    Joined:
    Feb 19, 2014
    Posts:
    168
    Sorry for the offtop question. That performance statistics on the right of your screen is some kind of plugin or is it yours?
     
    Camarent, Jan 19, 2021
    #2

  3. Suryansh55

    Suryansh55

    Joined:
    Jun 27, 2020
    Posts:
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    Plugin mate Graphy
     
    Suryansh55, Jan 19, 2021
    #3

  4. Camarent

    Camarent

    Joined:
    Feb 19, 2014
    Posts:
    168
    Thank you! This was exactly what I was looking for!
     
    Camarent, Jan 19, 2021
    #4

  5. pierred_unity

    pierred_unity

    Unity Technologies

    Joined:
    May 25, 2018
    Posts:
    431
    Hey, have a look at your temporal antialiasing settings on your game camera, there is an anti-flickering setting for instance. Have a play with all its settings and try to find a compromise between ghosting and sharpness.
     
    Last edited: Jan 19, 2021
    pierred_unity, Jan 19, 2021
    #5
    fuzzy3d likes this.

  6. Suryansh55

    Suryansh55

    Joined:
    Jun 27, 2020
    Posts:
    16
    Hii thanks for your reply but I did try TAA and it made nearly no difference I even tried disabling antialiasing as whole but they won't stop flickering , it is a bug in HDRP ? I played with many setting none of them seem to make any difference
     
    Suryansh55, Jan 19, 2021
    #6

  7. pierred_unity

    pierred_unity

    Unity Technologies

    Joined:
    May 25, 2018
    Posts:
    431
    It's hard to tell what's actually happening in your pitch black video. ;)

    Could it just be the light (as in emissive polys) having some z-fighting with the floor?

    The lamps in the HDRP templates have LODs, double check they aren't disappearing under the surfaces or clipping with the floor for instance.

    Also, looking at them, they're fine as they are, but you need to understand that if the room would be incredibly dark, you'll start getting aliasing as the lamp gets further away, and some of these bright LEDs in the lamp might appear and disappear randomly between frame (just aliasing, amplified by the bloom and exposure).
    upload_2021-1-19_19-38-53.png

    So, it's up to you to also design lamps that don't display that kind of artifact. You could for instance have a dome-shaped emissive part that will always show up and avoid (or prevent most of) the aliasing/flickering.

    Tiny bright polys are always a problem in 3d when you can't super sample, sometimes the assets must adapt.
     
    pierred_unity, Jan 19, 2021
    #7
    olavrv likes this.

  8. ashetynw

    ashetynw

    Joined:
    Feb 25, 2018
    Posts:
    4
    For anyone coming into this issue, my fix was pretty simple. It was an LOD issue for my scenario. The actual light objects themselves were too far into the mesh's housing so when the further away LODs were enabled, the light was actually not fully outside of the LOD mesh. Simply moving my light's out a bit further from the mesh toward the direction they were actually shining, is what fixed the flickering issue for me on all subsequent LOD's.
     
    ashetynw, Sep 16, 2023
    #8