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    Originally posted by Deathrey View Post
    Could that be fixed by calculating geometric normal using DDX/DDY and only use vertex normal when that fails.
    DDX/DDY is another alternative. This one would require a beefy fullscreen pass in order to gather at least 5 nearby pixels for normal reconstruction, and still would fail from time to time on some very thin / small geometry / alpha masked fences etc. Also performance overhead would be problematic for certain use cases like VR or mobile and force users to re-tweak bias parameters for those.

    Originally posted by Deathrey View Post
    Thanks, looks like something worth looking into.

    Comment


      Testing the slope solution in the 23 preview, and the results are very inconsistent. The slope bias helps a little, but it needs a huge value for close up distances, and this makes it broken in the distance. Looks like the bias is waay strong in distant cascades.

      Overall doesnt do much to me, when I solve the acne issue in close ups it broke in the distance and viceversa. Anyone has tested it? What are the better values?
      Check 3d tips! POLY DNA

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        Originally posted by II_ADN_II View Post
        Testing the slope solution in the 23 preview, and the results are very inconsistent. The slope bias helps a little, but it needs a huge value for close up distances, and this makes it broken in the distance. Looks like the bias is waay strong in distant cascades.

        Overall doesnt do much to me, when I solve the acne issue in close ups it broke in the distance and viceversa. Anyone has tested it? What are the better values?
        Ah ****, I was already expecting this. I am waiting for the full 2.23 release to see if the dynamic shadow issues have at least partially been fixed, but it seems it won't..

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          Any news on fixing the current implementation of the shadow slope bias?
          Check 3d tips! POLY DNA

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            Originally posted by II_ADN_II View Post
            Any news on fixing the current implementation of the shadow slope bias?
            Not yet, I am waiting for the full 4.23 release to see if anything new has been done to solve this problem. Fingers crossed lol

            Comment


              Originally posted by II_ADN_II View Post
              Any news on fixing the current implementation of the shadow slope bias?
              So now that I tested 4.23, I can safely say that the "fix" by Epic didn't really help. While it removes some of the shadow artifacts, it adds some on other parts of the terrain / mesh. Like II_ADN_II said, the results are very inconsistent.

              What's worse is that dynamic shadows now seem to be completely broken on landscape terrain in 4.23, I made a topic about that: https://forums.unrealengine.com/unre...n-on-landscape


              Also if I use Shadow Slope Bias, it makes static mesh shadows very unrealistic as can be seen in this picture:

              Click image for larger version

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              The only way to fix this is to set "Nu(mber) Dynamic Shadow Cascades" to a maximum, but that "adds significant render cost".
              Last edited by spacegojira; 09-10-2019, 08:38 AM.

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                Bump. Its a shame that this still an issue, right now it only needs to be consistent within all cascades.
                Check 3d tips! POLY DNA

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                  And I actually wondered why our preview spheres inside the Material Editor and also Landscapes getting this odd effect. Yes, it would be nice if this gets a very high priority very soon!
                  Tobias Löffler
                  Senior 3D Artist

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                    In case anyone missed it, 4.24 added new setting for directional lights, that being:

                    You can use it to adjust amount of biasing each directional shadow cascade has relative to the others.

                    As of 4.24, as I see it, issues, discussed in this thread, are safe to consider resolved.

                    Comment


                      So I just tested version 4.24 and the problem is still there. Furthermore, none of the introduced changes really fix the problems, as can be seen in the pictures. First is a dynamic light with standart settings, second is "shadow bias" and "slope bias" raised to the maximum, which has a little effect but it's still a huge problem and very noticable.


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                      Sadly it still makes the landscape or open world terrains unusable, as it's just really noticable and breaks the immersion. And the problem is that especially for procedurally generated terrains, you cannot place meshes on top of the shadows.

                      Epic, can you please get back to this problem and create a fix ASAP ??

                      Comment


                        Originally posted by spacegojira View Post
                        So I just tested version 4.24 and the problem is still there. Furthermore, none of the introduced changes really fix the problems, as can be seen in the pictures. First is a dynamic light with standart settings, second is "shadow bias" and "slope bias" raised to the maximum, which has a little effect but it's still a huge problem and very noticable.


                        Click image for larger version Name:	uebrokenshadows1.jpg Views:	0 Size:	100.5 KB ID:	1698008
                        Click image for larger version Name:	uebrokenshadows2.jpg Views:	0 Size:	89.2 KB ID:	1698009
                        Sadly it still makes the landscape or open world terrains unusable, as it's just really noticable and breaks the immersion. And the problem is that especially for procedurally generated terrains, you cannot place meshes on top of the shadows.

                        Epic, can you please get back to this problem and create a fix ASAP ??
                        Strange. I definitely did not feel that way and bias slider adjustment appeared like the only missing piece to me.
                        Just in case, the slider maximum is not the maximum value for biases. You can enter larger one by typing in.

                        Comment


                          Originally posted by Deathrey View Post
                          Strange. I definitely did not feel that way and bias slider adjustment appeared like the only missing piece to me.
                          Just in case, the slider maximum is not the maximum value for biases. You can enter larger one by typing in.
                          Thanks for the suggestion! Turning up Slope Bias to 10 (the maximum) removes most of the shadow artefacts, although it adds some artefacts at other locations. And I wonder what the performance impact of turning it this high is?
                          Last edited by spacegojira; 12-14-2019, 12:28 PM.

                          Comment


                            Originally posted by spacegojira View Post

                            Thanks for the suggestion! Turning up Slope Bias to 10 (the maximum) removes most of the shadow artefacts, although it adds some artefacts at other locations. And I wonder what the performance impact of turning it this high is?
                            It sucks doing so but you might need to place volumes that when you enter those you will switch the bias to other values to get rid of those artifacts. Not sure about the performance, since I don't remember ever looking at this part of the code, but if there is someone who can answer this is Deathrey for now.
                            Nilson Lima
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                              The problem is with procedural generated worlds, you can't know where to place those volumes. It's a shame that Slope Bias isn't a real solution to this problem.

                              Comment


                                Originally posted by spacegojira View Post

                                Thanks for the suggestion! Turning up Slope Bias to 10 (the maximum) removes most of the shadow artefacts, although it adds some artefacts at other locations. And I wonder what the performance impact of turning it this high is?
                                There is no performance impact of setting it to any value.


                                Originally posted by spacegojira View Post
                                The problem is with procedural generated worlds, you can't know where to place those volumes. It's a shame that Slope Bias isn't a real solution to this problem.
                                I doubt there is anything else meaningful, that could be done. The problem is universal to shadow mapping, but as of 4.24, Unreal does not feel capped in ways of dealing with it, compared to other rendering engines I've had a chance to work with. I'd add even more here, bias distribution adjustment ended up being better than I could expect. Being used to adjusting biases individually for splits, I gotta say that working with that slider speeds up your shadow setup with no takeaways.

                                The rest of dealing with the issue lies within shadow and scene setup.

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