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Feature Request Add "Clear" as a simple HDRP Volumetric Sky option for 2022.2(b8)

Discussion in 'High Definition Render Pipeline' started by akent99, Sep 17, 2022.

  1. akent99

    akent99

    Joined:
    Jan 14, 2018
    Posts:
    492
    I was testing blending weights of volumetric sky in 2022.2b8. During testing, I tried to blend from blue skies to sparse to overcast.

    I tried adjusting the sparse weight slowly upwards without a "Clear" profile, and with weight 0 I had blue skies.
    upload_2022-9-17_13-56-17.png

    At weight 0.01 for the sparse volume I had quite dense skys suddenly appear.

    upload_2022-9-17_13-57-15.png

    At weight 1 I had sparse skies

    upload_2022-9-17_13-57-44.png

    So blending the weight from 0 (blue skies) to 1 (sparse skies) went from blue to a bit dark to lighter. I assume I should put a "clear skies" volume with lower priority than the sparse volume, but my attempts did not come out looking right and did not blend from nothing to sparse properly. E.g. 50% weight did not look half strength of sparse, and near zero I had all sorts of funny artifacts going on.

    So my request is to include a correct "Clear" simple sky preset so you can adjust from Clear to Sparse using weights and have clouds go from blue skies to sparse in a nice blend (basically have "lighter than sparse" without resorting to learning custom settings - as a novice user it turned out harder than expected to get a Clear volume right).

    [Note: Going from sparse to overcast etc did work.]
     
  2. pierred_unity

    pierred_unity

    Unity Technologies

    Joined:
    May 25, 2018
    Posts:
    423
    Hey,

    By default, when you enable the clouds, they fall back to a cloudy look.

    So to have a "true" clear base look when you activate the clouds, you just need to make your own base preset with the look you desire, so that when it starts blending with other presets, it won't jump to cloudy at first.

    You don't need a clear preset btw, you just need a preset with a density at 0:

    upload_2022-9-26_14-20-37.png

    Or you can also modifier the default HDRP volume setting under Project Settings > HDRP Global Settings > Default Volume Profile Asset

    upload_2022-9-26_14-23-8.png
     
  3. akent99

    akent99

    Joined:
    Jan 14, 2018
    Posts:
    492
    Thanks, its just setting density alone to zero does not look very good blending from "clear" (density = 0) to sparse. I messed around for a while, but never got settings quite right. That is what led to the request - for people who don't want to learn the intricacies of clouds (which is I assume what "simple" is for). For example, here are some steps along the blend of weights between the two volumes (clear skies to sparse).

    upload_2022-9-26_7-36-0.png

    upload_2022-9-26_7-36-20.png

    upload_2022-9-26_7-36-55.png

    Basically the clouds appear, then are bigger then get smaller as you blend to sparse. Their height also changes during the blend (they go higher). So there is more to it that just going "custom" with density set to zero - the intermediate values are not right when the weights are between the start and end point.

    I am sure its *possible* to come up with a "clear" profile that is right - the feature request was that its not easy to do that looks good when blending (without understanding all the settings), so if you are providing presets so non-experts can use it and get decent results, I am suggesting a "Clear" simple profile that you test with blending to all the other profiles to make sure the intermediate states look sensible as well. The current simple profiles are great - there is just a gap to me in that blue skies are missing (and its not trivial to get right).
     
  4. pierred_unity

    pierred_unity

    Unity Technologies

    Joined:
    May 25, 2018
    Posts:
    423
    If you made a "Clear" preset yourself based on the Sparse preset, clouds will be small to begin with, they won't go "bigger then get smaller as you blend to sparse". Of course if you start from Cloudy or Stormy, things will more around.

    Ways to avoid clouds moving up and down: make sure the altitude range is constant between your volume profiles. For instance, have a global one that set the range you please, then don't override it for all the other volume profiles blended on top of it.
    upload_2022-9-26_16-42-12.png


    However, this is not something we'll do for you, because our cloud presets are based on realistic altitude range for given types of clouds. So if you really want your altostratus and low level cumulus clouds (and blue sky preset) to have the exact same altitude, you'll need to do it yourself. ;)

    Here's an example below of "Clear (from Sparse with 0 density)" -> "Sparse" -> "Cloudy" -> "Sparse" -> "Stormy", where they all share the same altitude range, if that's what you really want. It doesn't necessarily create good-looking types of clouds, but if you do not want them to change altitude at all (this is just for education purpose only).

    2022-09-26_17-20-24.gif
     
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