Announcement

Collapse
No announcement yet.

[Twitch] Subsurface Scattering and Ray Traced Soft Shadows Demos - Oct. 16, 2014

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    #46
    Originally posted by Martin Mittring View Post
    Long Quote
    Thanks for answer!

    I have one more question, for anyone able to answer it.

    Any plans on improving Atmospheric Fog ? It's all nice but there few things that bother me, from most important to least:
    1. Sun- Let's just be honest about it. It looks like **** (;. No matter how high brightness you set, it still looks like flat disk, that is just brighter on the outside. It looks like it is missing HDR.
    2. Night. I mean separate settings for night with moon. I managed to exploit some settings, to have dark sky with bright moon, but that just feels like ugly hack.
    https://github.com/iniside/ActionRPGGame - Action RPG Starter kit. Work in Progress. You can use it in whatever way you wish.

    Comment


      #47
      Thanks for a great stream folks! Given my background as a lighting artist, it was especially interesting to hear what you're doing with soft shadowing. Very cool.

      However, I was upset by Martin's admission of stereo (thus VR) being a second-class citizen. I'm sure that's a practical truth, as there are many fewer VR folks than 2D folks in the mix. But I can't help but pipe up, that the only reason I've joined the UE4 subscription is for it's support of VR. For the first time since April, I've cancelled my subscription. I don't say that to be a petty child, though it sounds that way. I say that because it is the practical thing for me to do.

      I was the first person to report that the new SSS wasn't working in VR. I posted it in forums and in AnswerHub probably 2 days after the 4.5 Preview was released (2 weeks ago?), so it was annoying to hear that Martin didn't even know it to be a problem.

      Given that VR isn't going away, but will become a larger slice of the pie in upcoming years, I would ask that some testing time be applied to making sure new features work for it. As he said, it may be a simple oversight. So why not test and fix said oversight before shipping? Especially since someone (passive-aggressive-me took the time to report the problem 2 weeks ago.

      Also, Martin's quote earlier in this thread, "I don't think we will spend time on that, dynamic lighting methods are not a good fit for VR where you need super high resolution + 90fps." This was regarding DFAO, but I'm not clear if it is also regarding SSS in VR. I would ask that you let the users decide if a feature is too expensive for VR. If it is, we won't use it. But if we are demo-ing on specific-built hardware (say beefy machine for a conference), we may have very good reason to use expensive features in VR. Please don't make such assumptions for us, unless it is completely untenable.

      Sorry for the rant. I know you guys are very busy, and have a LOT to take care of. I just had to get that off my chest, and make it clear that this was quite disappointing for this particular user. And Martin, I'm sorry for singling you out. I don't want to come off as attacking you. That's not my goal, I just have my own biased concerns.

      Andrew Weidenhammer (aka - 3dLight)
      Last edited by 3dlight; 10-18-2014, 12:49 PM.

      Comment


        #48
        Originally posted by iniside View Post
        Thanks for answer!

        I have one more question, for anyone able to answer it.

        Any plans on improving Atmospheric Fog ? It's all nice but there few things that bother me, from most important to least:
        1. Sun- Let's just be honest about it. It looks like **** (;. No matter how high brightness you set, it still looks like flat disk, that is just brighter on the outside. It looks like it is missing HDR.
        Bloom in directional light properties overcomes that problem but then there is that weird flickering issue with bloom. We either need a better bloom solution or something else in atmospheric fog itself.
        FREE VR Drum Kit Project
        FREE Color LUT Collection
        FREE Physics Driven Spacecraft Project
        FREE GTA Style Vehicle Interaction
        Dynamic DoF(Depth of Field)
        Camera Crossfade

        Comment


          #49
          Hi there.

          I saw in the stream that there is the distance field debug view so visualize the distance fields. Is there a way that we can write a shader to volumetrically trace though the distance field to render volumetric clouds in game? The visualisation looked pretty fast so just wondering if it was possible. I'm going to have a look and see if I can find the relevant code in the source and pick it apart.
          Visual Effects Artist, Weta Digital, Wellington New Zealand
          BLOG www.danielelliott.co.uk
          @danielelliott3d https://twitter.com/danielelliott3d
          Unreal Engine and VFX Tutorials https://www.youtube.com/user/DokipenTechTutorials
          2015 Showreel: https://vimeo.com/116917817

          Comment


            #50
            Sorry if this sounds silly, I'm no graphics engineer, but is there any reason the distancefield meshes need to be generated? From what I can see the result are rather blobby and weird until you tweak the settings. I was wondering why they are generated in this way, instead of using an artist-supplied low LOD model.
            Distance fields provide the signed distance to nearest occluder at any point in space and this allows us to efficiently solve occlusion cone traces from any point in the scene to any other point. This is super powerful and allows all kinds of dynamic lighting techniques previously impossible.

            Any plans on improving Atmospheric Fog ?
            I dont' think we have an plans to work on that atm, but thanks for the feedback and letting us know what needs improved.

            However, I was upset by Martin's admission of stereo (thus VR) being a second-class citizen.
            The reason it is second class is just due to time constraints and the relative importance vs other UE4 use cases. There are effectively infinite high priority tasks that we have to do. But even so, I think our VR support is pretty good and it is really only new features that lag in VR support.

            it was annoying to hear that Martin didn't even know it to be a problem.
            It is a new feature and just the work to get it out the door without testing with VR is immense.

            So why not test and fix said oversight before shipping?
            A not-yet-implemented feature isn't an oversight or even a bug, it's just a not-yet-implemented feature. Support for VR of every rendering technique in the engine is a feature, it requires special work to get them to cooperate.

            Is there a way that we can write a shader to volumetrically trace though the distance field to render volumetric clouds in game?
            Distance fields represent distance to nearest surface, so they can't be used to represent volumetric primitives which have varying density throughout (although it could be used to represent the bounds of the volumetric data, to accelerate rays going toward the volume, just not rays inside the volume). For volumetric data standard volume ray marching techniques are needed and it costs a lot more than tracing through a distance field where you can skip empty space.

            The visualisation looked pretty fast so just wondering if it was possible.
            It takes about 5ms on a fast GPU at half res. It is barely optimized so could easily be quartered in execution time. There could definitely be some interesting game visuals from leveraging these distance fields.

            I'm going to have a look and see if I can find the relevant code in the source and pick it apart.
            Search for VisualizeMeshDistanceFieldCS.

            Comment


              #51
              Originally posted by DanielW View Post
              Distance fields provide the signed distance to nearest occluder at any point in space and this allows us to efficiently solve occlusion cone traces from any

              It is a new feature and just the work to get it out the door without testing with VR is immense.

              A not-yet-implemented feature isn't an oversight or even a bug, it's just a not-yet-implemented feature. Support for VR of every rendering technique in the engine is a feature, it requires special work to get them to cooperate.


              Search for VisualizeMeshDistanceFieldCS.
              Thanks for answering. Fair enough about VR not being first on your list, but I suppose my point was that I feel any new rendering feature should include VR support before it is released. If this is not the way your team wishes to treat VR support (this is fine, I understand there is great value in releasing to most users early), then you should properly warn customers of that. I think quite a few folks have jumped into UE4 because it DOES have great VR support. There's no denying that, and I thank you for it! But if a new feature isn't tested, or shown not to work in VR, I think folks would appreciate a warning, so they aren't subscribing for heartbreak Am I complaining that I wasted 20 bucks? Well personally, no. I think the upgrade is huge and more than worth it, but I can't help but think going forward it would be nice for more communication about VR support on new features.

              Andrew

              Comment


                #52
                Out of curiosity. Distance Fields are stored in GPU memory or in general memory ?
                https://github.com/iniside/ActionRPGGame - Action RPG Starter kit. Work in Progress. You can use it in whatever way you wish.

                Comment


                  #53
                  http://developer.amd.com/wordpress/m...GRAPH_2006.pdf

                  Page 153. Using SDF for diffuse GI. It's bit old, but might be worth reading.

                  Edit:

                  http://erleuchtet.org/~cupe/permanen...re_tracing.pdf

                  Paper about optimizing sphere tracing performance.
                  Last edited by iniside; 11-01-2014, 08:19 AM.
                  https://github.com/iniside/ActionRPGGame - Action RPG Starter kit. Work in Progress. You can use it in whatever way you wish.

                  Comment

                  Working...
                  X