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Unity HDRP or UE5 LUMEN for Realtime Non Baked CINEMATICS only

Discussion in 'Virtual Production' started by morfevs, Sep 18, 2022.

  1. morfevs

    morfevs

    Joined:
    Dec 21, 2016
    Posts:
    20
    Hi all,

    I have been using Unity for many years. I always found it to be usable and most important - allowed me in the fastest way - to achieve results be from aid from the asset store, to implemented solutions in the engine.

    I use Unity mostly to create cut scenes, then capture them with Recorder. So I have no need for framerate. With recorder it captures frame by frame and it does not matter if it barely runs.

    Nowadays I am reading in various places about UE and LUMEN GI. So my questions is this:

    - Will Lumen look better than the current Real Time GI found in Unity2020 or later? or its very similar? What is Unity counter to Lumen?

    - In UE does it capture frame by frame independently from how "smooth" it runs on play?

    - I need to animate simple mechanical parts, like a robotic arm. I use Pivot and hierarchies to do this in Unity. I assume that UE has a similar way?

    - I do not need or have the time for baking so I use real time only to create cutscenes.

    Thanks for your input :eek:)
     
  2. hippocoder

    hippocoder

    Digital Ape

    Joined:
    Apr 11, 2010
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    Unity's equivalent is HDRP, which uses raytracing hardware. This is a valid, and genuine equivalent. Lumen is a different approach. I would say it is more inaccurate than Unity's but probably more optimised overall for performance.

    Unity's is more about accuracy and ground truth, it uses RT hardware to perform these calculations, but does require more setup.

    You'll want to ask these questions on the Unreal forum. Unreal does have a lot of temporal reliance so it will likely require tweaking Lumen until it's functionally slower but less temporal. At the time of writing, there's a few hacks they use like disabling and enabling meshes to force an update. This behaviour will probably change in future.

    It does, but these are all questions that are best answered on Unreal's own forums.

    I agree - none of us should be baking for the high end or cutscenes.

    Ultimately though you're asking Unreal questions on the Unity forum. Please do ask the same questions over there for a rounded answer.
     
  3. newguy123

    newguy123

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    Aug 22, 2018
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    1,281
    The nice thing about Lumen, is that you DONT NEED high end RTX cards to calculate. You can run Lumen in software mode, or on hardware mode (if you have the high end hardware).

    Another great thing about lumen, it gives you not only realtime GI, but it also gives you REAL realtime reflections, without needing probes. So in Unity for better results, you need reflection probes for fallback, even if you dont bake them and set them to realtime probes.

    Pathtracing in Unity is pretty solid, although if we're talking about 360 renders, then Unity falls short as you'll need to code your own custom solution as by default, recorder does not work with pathtracing and 360 renders. If you select 360, then you loose the ability for accumulation, as you only get the result of the 1st frame of the pathtracing before the image converges. If you render regular output, like 4K image through regular camera, then accumulation works fine with pathtracing.

    Unreal seems ahead pathtracing rendering currently as they support instances, where Unity ony recently came up with a solution and we're awaiting it to be added to the 2023.1 alpha.......in alpha 10 it does not seem to be in there yet. We're talking about an equivalent of Graphics.Draw for raytracing/pathtracing here...
    See this thread for more info on that: https://forum.unity.com/threads/doe...instancing-in-hdrp-12-1.1194841/#post-8372169
     
  4. hippocoder

    hippocoder

    Digital Ape

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    Again there are pros and cons to Lumen. Like reflections are very low resolution at the moment, and so on. Therefore it is best everyone tries the relevant tools out (free to do so) and come to real conclusions for their own use-cases.
     
  5. morfevs

    morfevs

    Joined:
    Dec 21, 2016
    Posts:
    20
    Hi all. Thanks for your great replies!

    One thing I am immediately noticing, regarding my Unreal / Unity questions is how active is the community and not only active, also helpful.

    Unity is a FAMILY. Just look at this discussion, various points of view from experienced users. I did the same in the Unreal forum. No one cares :eek: zero reply.

    I am getting Unreal to try it out. Another solution is to Bake with Bakery in Unity, especially for interiors, they look fantastic.

    I have a 3080 notebook, in theory that should be enough to run Lumen on hardware?
     
  6. newguy123

    newguy123

    Joined:
    Aug 22, 2018
    Posts:
    1,281
    Yes 3080 should be fine. One thing though, if you go Bakery route, which may look nice, that defeats the purpose of your original question.

    Maybe also look into APV in Unity (Adaptive Probe Volumes). Its a new experimental thing that is in 2021.2 and its a new way to approach lighting and helps with GI:
    https://forum.unity.com/threads/ada...erimental-release-for-hdrp-in-2021-2.1238824/
     
    Last edited: Sep 20, 2022