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    Okay, so after some technical difficulties, the last session is recorded! I think its over 2h and the arctic environment is finished up, so you dont need to wait any longer

    I am still comping the thing since the nvidia experience likes to chop stuff into many parts, but I hope to have it online tomorrow!

    Here is a small tease:
    Click image for larger version

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    And here are the original shots from Sascha again for reference https://www.artstation.com/artwork/vBbYv

    Cheers!
    Attached Files
    Last edited by Daedalus51; 03-26-2017, 01:53 PM.
    Check out UNREAL 4 Lighting Academy
    https://forums.unrealengine.com/show...ng-like-that-)

    Comment


      Hey Daedalus51, I'm very much interested in taking part of this session you are offering. How would I go about setting one up with you? Thanks

      Comment


        Originally posted by KHM3dia View Post
        Hey Daedalus51, I'm very much interested in taking part of this session you are offering. How would I go about setting one up with you? Thanks
        I just sent you a PN

        For everyone else, the next part is now online! Since the last session turned out to be so long, this is Part 1 and Part 2 will be available tomorrow morning^^ The session is finished with those last 2 parts, so we can think about what we all would like to see as a next project



        Hope you guys like it and have a great time!

        Cheers!
        Check out UNREAL 4 Lighting Academy
        https://forums.unrealengine.com/show...ng-like-that-)

        Comment


          Hello Daedalus51, nice stuff like always.

          I think the "Use Area Shadows for Stationary Light" works with the same limitations, it's something you don't mention because you don't have to, but the main advantage of using Stationary is the blending between Static and Dynamic objetcs with the same shadow.

          It's btw my main problem with my map (SGC from Stargate), it's a very tight place with many lights and I need a good blending between the player, dynamic objects and statics.

          I use a little trick for the corridor for example, I place Static Lights and when I'm happy with the render, I divide by two the intensity and multiply the GI by two as well, duplicate all the concerned lights and put them in dynamic. This way I don't use any channels for shadows and I still have nice dynamic shadows with dynamic objects.

          However, this trick only work well with "bright" area, when it's too dark, shadows are a little bit off, if you have a very dark area baked, you can't darken a shadow from a movable unfortunately.

          Something very important to know as well from the Stationary is, this light bake shadows only on Static Objects and dynamic shadows are only active on Dynamic Objects, you can't have both, I really wish to have a way to use both in near distance (or a way to receive dynamic but cast static), in CS:GO Valve did that with the sun, the dynamic shadow is over the bake and with the distance the transition is pretty clean.

          If you are curious about my work in progress

          Ps : OBS shouldn't do "parts", but if you want to keep Shadowplay give a try to avidemux to stitch your videos
          Last edited by EXpMiNi; 03-28-2017, 12:34 PM.
          CG Artist for StarGate Network
          Discord : https://discord.gg/CYBkFWD

          Comment


            Great stuff. The depth and contrast you are able to bring to these projects is really inspiring.

            Comment


              Originally posted by EXpMiNi View Post
              Hello Daedalus51, nice stuff like always.

              I think the "Use Area Shadows for Stationary Light" works with the same limitations, it's something you don't mention because you don't have to, but the main advantage of using Stationary is the blending between Static and Dynamic objetcs with the same shadow.

              It's btw my main problem with my map (SGC from Stargate), it's a very tight place with many lights and I need a good blending between the player, dynamic objects and statics.

              I use a little trick for the corridor for example, I place Static Lights and when I'm happy with the render, I divide by two the intensity and multiply the GI by two as well, duplicate all the concerned lights and put them in dynamic. This way I don't use any channels for shadows and I still have nice dynamic shadows with dynamic objects.

              However, this trick only work well with "bright" area, when it's too dark, shadows are a little bit off, if you have a very dark area baked, you can't darken a shadow from a movable unfortunately.

              Something very important to know as well from the Stationary is, this light bake shadows only on Static Objects and dynamic shadows are only active on Dynamic Objects, you can't have both, I really wish to have a way to use both in near distance (or a way to receive dynamic but cast static), in CS:GO Valve did that with the sun, the dynamic shadow is over the bake and with the distance the transition is pretty clean.

              If you are curious about my work in progress

              Ps : OBS shouldn't do "parts", but if you want to keep Shadowplay give a try to avidemux to stitch your videos
              Haha...man, already 3 people recommended OBS to me now. I will definitely have a look at it

              Regarding Stationary lights...I have to admit that I slightly disagree with you^^

              The thing is this: "3 lights per object limitation" this one ONLY exists because of the distance field shadowmap that is being generated by the stationary mode. Static lights dont have that, which is the reason static light baked shadows look worse with low lightmnap rez. When turning on area shadows for you stationary light, it actually defaults back to the old shadow baking technique JUST with soft penumbras. So in theory, that should get rid of that 3 lights per object limitation since its not using the same shadowing technique anymore. I actually think that this behavior is a bug, but I will ask Daniel Wright about it, he should be the guy that knows exactly whats going on there^^

              About mixing baked and shadows with dynamic objects...I agree that stationary lights help with that, but there is an even more important reason why you want to use as many stationary lights as you can: specular and the dynamic direct lighting. You wont get any specular from static lights, so if you want to have nice little lights on a element close to the ground and you want GI from them AND specular reflection, you need to use stationary and turn off shadows to get past that limitaion.

              I almost always want specular from all my main light sources which is why stationary lights are so important. Also, subsurface gets only affected by dynamic direct lighting. Static lights will not "bleed" through sub surface materials, you need "dynamic" direct lighting for that...and since I also want to have baked GI from those lights, I have to use stationary^^

              While I do agree with you in some points, the difficult thing here is clearly that not all approaches work well with each other and depending on your needs, some things are more important than others or wont work at all. I strongly believe that fixing this behavior for stationary lights would be a huge improvement. Right now, you cant have a light that can make GI for lightmass, has specular AND it doesnt matter how many you have...so thats clearly something that can be improved. Also, if you think about it, that behavior doesnt make any sense from a logical standpoint: You can have unlimited static lights that bake GI and shadows but have no runtime specular. You can have unlimited (until your performance is dead^^) movable lights that have runtime specular but dont bake GI. So why cant you have a light that bakes the same way as the static does but also has dynamic runtime direct light and specular?

              Well aaaaanyways, I am getting side tracked I will ask Daniel about whats going on there, maybe he can shed some light into this (no pun intended :P)

              Thanks again for the constructive feedback! I love talking and sharing ideas about this stuff!

              Cheers!

              EDIT: lets do it like this: [MENTION=404]DanielW[/MENTION] any idea if what we discuss above is unexpected behavior or not? Would be awesome to get some clarity on how its supposed to work. Maybe I got it all wrong
              Last edited by Daedalus51; 03-28-2017, 03:00 PM.
              Check out UNREAL 4 Lighting Academy
              https://forums.unrealengine.com/show...ng-like-that-)

              Comment


                I completely agree with you about the weird logic behind Stationary Light, I think area shadows is just here to have more control on it and it's not a bug, it's just not very clear and we need more options to have the choice to enable something or not (and I strongly believe the limitation is here just for the shadows blending between static and dynamic), like turn off completely specular on movable, enable specular on static, etc.

                What you want is exactly to do my trick but with only one entitie (specular option + dynamic shadow in complement of the static).

                The only big bug I found with spotlights is when you have a movable and you push the Attenuation Radius too far, you don't cast shadowmaps anymore for some reason.

                But maybe you're right, it's a bug and I've been fooled by the weird logic behind this light ^^.
                Last edited by EXpMiNi; 03-28-2017, 04:29 PM.
                CG Artist for StarGate Network
                Discord : https://discord.gg/CYBkFWD

                Comment


                  Originally posted by EXpMiNi View Post
                  I completely agree with you about the weird logic behind Stationary Light, I think area shadows is just here to have more control on it and it's not a bug, it's just not very clear and we need more options to have the choice to enable something or not (and I strongly believe the limitation is here just for the shadows blending between static and dynamic), like turn off completely specular on movable, enable specular on static, etc.

                  What you want is exactly to do my trick but with only one entitie (specular option + dynamic shadow in complement of the static).

                  The only big bug I found with spotlights is when you have a movable and you push the Attenuation Radius too far, you don't cast shadowmaps anymore for some reason.

                  But maybe you're right, it's a bug and I've been fooled by the weird logic behind this light ^^.
                  Well....again, I am not really sure if it is a bug! Its just that it feels like it would be one based on my knowledge on how this technique works. But yeah, I might be totally wrong with that until Daniel de-mystifies it

                  Regarding your shadowing issue....I am not sure what I am looking at in your screenshot I can see some shadows working and I dont see the radius of the light....so its hard to judge^^ However, if I am not mistaken, Unreal uses screen percentage culling for shadows. That means that even if something is in the radius of a light and both, the geometry and the light have cast shadows enabled, the shadow could still be not visible for that object because the actual area the shadow would cover in screenspace is below a certain threshold. So that optimization makes the shadow go away. Thats just a guess though. Do the shadows reappear when you move closer to the geometry that is supposed to cast the shadow (with you camera, not with the light)? That could be an indicator for this.

                  Cheers!
                  Check out UNREAL 4 Lighting Academy
                  https://forums.unrealengine.com/show...ng-like-that-)

                  Comment


                    I have been summoned.

                    The thing is this: "3 lights per object limitation" this one ONLY exists because of the distance field shadowmap that is being generated by the stationary mode. Static lights dont have that, which is the reason static light baked shadows look worse with low lightmnap rez. When turning on area shadows for you stationary light, it actually defaults back to the old shadow baking technique JUST with soft penumbras. So in theory, that should get rid of that 3 lights per object limitation since its not using the same shadowing technique anymore.
                    The limitation is 4 shadow casting stationary lights affecting any point in space. The directional light consumes one everywhere so you effectively get 3 for point / spot lights.

                    Static lights bake all their lighting and shadowing into the lightmap so they don't have any limitation on overlap but they also can't ever integrate properly with shadowing from movable objects and characters.

                    Stationary lights bake out their shadowing separately for each light. In the deferred renderer we have to get these shadow factors from the BasePass (where lightmap UVs are available) to the deferred lighting passes so we have to pack the 4 shadow factors into the GBuffer. This is why the limit of 4 exists - to keep the GBuffer small as it's like a performance tax on the entire deferred renderer. The Forward renderer also has a 4 shadow casting overlap limit, but for slightly different reasons.

                    So regardless of whether you choose 'Use Area Shadows for Stationary Light' or not, we still have to store out shadow factors separately for each stationary light to support combining with dynamic shadowing and the 4 overlap limit is the same.

                    You wont get any specular from static lights
                    Technically static light sources are drawn into reflection captures so you do get direct specular from static lights if you have reflection captures setup, but yeah it won't be anywhere near the quality of Stationary lights, which have correct parallax and are shadowed correctly.

                    Right now, you cant have a light that can make GI for lightmass, has specular AND it doesnt matter how many you have...so thats clearly something that can be improved.
                    It is possible to support more than 4 shadow casting stationary lights affecting a single point, but it would add rendering overhead (either another GBuffer, or re-render the scene's meshes again to output the next 4 shadowmap channels) so we haven't tackled it yet.

                    Comment


                      Originally posted by Daedalus51 View Post
                      Do the shadows reappear when you move closer to the geometry that is supposed to cast the shadow (with you camera, not with the light)?
                      Nope, but I partially solved the issue, I put 5000 instead of 50000 to the Attenuation Radius (stretch the shadowmap so far isn't a good idea ), the problem is less visible, I've always this Shadow Bias problem (I can't go lower without artefact), but it's much better, I will find a solution, like always.



                      Sometimes I wish to have a bridge between Arnold/Vray/Redshift/etc. to UE4 for the lighting, I don't know if they have any plans to enhance the lighting part to boost everything up.

                      Edit : it's not so bad https://streamable.com/t4up6, it's pretty weird than the planar reflection catch the light when the door is closed though.
                      Last edited by EXpMiNi; 03-29-2017, 11:26 PM.
                      CG Artist for StarGate Network
                      Discord : https://discord.gg/CYBkFWD

                      Comment


                        Originally posted by EXpMiNi View Post
                        Nope, but I partially solved the issue, I put 5000 instead of 50000 to the Attenuation Radius (stretch the shadowmap so far isn't a good idea ), the problem is less visible, I've always this Shadow Bias problem (I can't go lower without artefact), but it's much better, I will find a solution, like always.



                        Sometimes I wish to have a bridge between Arnold/Vray/Redshift/etc. to UE4 for the lighting, I don't know if they have any plans to enhance the lighting part to boost everything up.

                        Edit : it's not so bad https://streamable.com/t4up6, it's pretty weird than the planar reflection catch the light when the door is closed though.

                        I think you dont have enough resolution for a shadowmap with that huge radius. Try increasing the rez via console, that should fix it
                        Check out UNREAL 4 Lighting Academy
                        https://forums.unrealengine.com/show...ng-like-that-)

                        Comment


                          Originally posted by DanielW View Post
                          I have been summoned.



                          The limitation is 4 shadow casting stationary lights affecting any point in space. The directional light consumes one everywhere so you effectively get 3 for point / spot lights.

                          Static lights bake all their lighting and shadowing into the lightmap so they don't have any limitation on overlap but they also can't ever integrate properly with shadowing from movable objects and characters.

                          Stationary lights bake out their shadowing separately for each light. In the deferred renderer we have to get these shadow factors from the BasePass (where lightmap UVs are available) to the deferred lighting passes so we have to pack the 4 shadow factors into the GBuffer. This is why the limit of 4 exists - to keep the GBuffer small as it's like a performance tax on the entire deferred renderer. The Forward renderer also has a 4 shadow casting overlap limit, but for slightly different reasons.

                          So regardless of whether you choose 'Use Area Shadows for Stationary Light' or not, we still have to store out shadow factors separately for each stationary light to support combining with dynamic shadowing and the 4 overlap limit is the same.



                          Technically static light sources are drawn into reflection captures so you do get direct specular from static lights if you have reflection captures setup, but yeah it won't be anywhere near the quality of Stationary lights, which have correct parallax and are shadowed correctly.



                          It is possible to support more than 4 shadow casting stationary lights affecting a single point, but it would add rendering overhead (either another GBuffer, or re-render the scene's meshes again to output the next 4 shadowmap channels) so we haven't tackled it yet.
                          Yeah! Thank you so much Daniel! This is really explaining it nicely Makes a lot more sense to me now.
                          Check out UNREAL 4 Lighting Academy
                          https://forums.unrealengine.com/show...ng-like-that-)

                          Comment


                            Aaaand here is the last part for your viewing pleasure!

                            Check out UNREAL 4 Lighting Academy
                            https://forums.unrealengine.com/show...ng-like-that-)

                            Comment


                              added your playlist. i hope you will show the egiptian tomb scene or what is that. looks really good

                              Comment


                                really nice outcome of this scene, thanks for all the precious info's!

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