Search Unity

  1. Megacity Metro Demo now available. Download now.
    Dismiss Notice
  2. Unity support for visionOS is now available. Learn more in our blog post.
    Dismiss Notice

Question Confused on Sun Intensity in Daylight HDRP Scene

Discussion in 'High Definition Render Pipeline' started by Glader, Jul 14, 2020.

  1. Glader

    Glader

    Joined:
    Aug 19, 2013
    Posts:
    456
    I have poured over MANY posts, dating back as far as 2018, and watched a few different videos relating to lighting in HDRP. However, nobody seems to agree on exposure or light intensity for daylight scenes. I'm going crazy!

    I see examples using 1,000 LUX for the directional sun, sometimes 10,000 and other times 100,000-128,000. When consulting documentation I see recommendations of approximately 100,000. When I consult Wikipedia LUX charts I see recommendations of 100,000-ish and EV of something like 12-13-ish.

    This is what I use but is it right? Honestly some of the scenes I see that use these other values look more correct and visually stunning. They look way better than what I'm currently seeing in my scenes. Am I doing it wrong?? I am going crazy trying to use HDRP.
     
  2. pierred_unity

    pierred_unity

    Unity Technologies

    Joined:
    May 25, 2018
    Posts:
    433
    Hello, you're free to use whatever system you want in practice, as long as you understand the drawbacks.

    You could use a sun at 1 lux with a low exposure value for the camera (<0). And if you balance it well (with the sky and other light sources), it will look fairly close to a physically correct lit scene with ~100 000 lux and 13.5 EV.

    If it doesn't look "stunning" it's most likely due to your setup, not HDRP itself.

    Indeed, some post-FXs will look better when using the correct lighting range. So it's obviously preferable to light using the right values, yet experts can easily go around this and stick to smaller light values if they know what they're doing. That's how many games are still lit these days.

    By analogy, you could set the mass of your objects to be only a thousandth of their real counterpart, but you'd have to tune the physic system in your project to compensate for that totally fantasy mass. Doable, but not recommended. Same applies to any rendering/lighting system.

    I'd recommend you look at the Exposure and Lighting setup section of this video if you're unclear about this topic:



    Also, a new HDRP template is coming eventually, with correct light intensities. The current one (the workbench level), is not lit with physically-based values, and can indeed be confusing.
     
    Glader likes this.
  3. Bordeaux_Fox

    Bordeaux_Fox

    Joined:
    Nov 14, 2018
    Posts:
    589
    I think a lot of people having problems with the general sun intensity and exposure. Therefore, the template scene is very misleading and confusing people. Why not make this beautiful courtyard scene to the default template scene? Your already have it finished. Merging the scene into HDRP branch would just take some minutes.
     
  4. valarnur

    valarnur

    Joined:
    Apr 7, 2019
    Posts:
    438
    2020.2 HDRP will have PR template.
     
  5. Bordeaux_Fox

    Bordeaux_Fox

    Joined:
    Nov 14, 2018
    Posts:
    589
    Thanks god, far too late, but still better than never. :)