Dynamic shadows artifacts

anonymous_user_f75af9d3 · April 22, 2019, 9:15am

omg… so, isn’t solved yet??

spacegojira · April 23, 2019, 6:25pm

No and don’t get your hopes up that it will be fixed anytime soon.

IOchair · April 24, 2019, 5:33am

I have heard that this bug will never be fixed. After completing the render graph, they will switch to PCSS.

anonymous_user_fbe2d247 · April 24, 2019, 7:49am

Do you have any source for that?

spacegojira · April 24, 2019, 10:54am

I would love the source for that as well, especially if it mentions a timeframe.

IOchair · April 25, 2019, 2:19am

Sorry, there is no source. I heard from a company employee who can seek business technical support from Unreal.

spacegojira · April 25, 2019, 7:07am

Okay so basically a hoax. Got it.

NilsonLima · April 25, 2019, 1:19pm

PCSS is mentioned at Roadmap as future releases, no ETA. https://.com/b/TTAVI7Ny/ue4-roadmap

Chosker · April 25, 2019, 1:31pm

well PCSS would mean replacing broken with expensive. when you’re developing for something like the Switch or any other current-gen console, “broken vs expensive” isn’t really a choice :rolleyes:

IOchair · April 26, 2019, 3:41am

Ok, I was wrong.
I just saw the shadow slope bias in dev-rendering:D

anonymous_user_fbe2d247 · April 26, 2019, 10:55am

Can you share link for this change?

Deathrey · April 26, 2019, 11:15am

https://github.com/EpicGames/UnrealEngine/commit/aa683b3139e1a4faab5f44fef752cd624966a1a0#diff-558178f0925504d94d8e79a5cc281d83

II_ADN_II · May 2, 2019, 11:09pm

Pretty much this. Even not developing for switch, is it that bad wanting to achieve the best performance possible?

slope depth bias its the ideal way to solve the problem. Can this behaviour be implemented in the main branch? Can it be moved to a plugin? Are those files the only ones needed to implement the slope bias?

Denoise usually means way more expensive than the traditional solution.

Wow, the voxel solution in the video is beautiful. That thread was a year ago, and no news on this topic (T_T)

And by the way, shadow proxyes or shadows with lower LODs will be helpful on improving performance for sure.

Zeblote · May 2, 2019, 11:25pm

Anyone tested the slope bias yet?

anonymous_user_f75af9d3 · May 7, 2019, 12:29am

slope bias option?? where??? in the 4.22???

II_ADN_II · May 7, 2019, 2:12am

https://github.com/EpicGames/UnrealEngine/commit/aa683b3139e1a4faab5f44fef752cd624966a1a0#diff-558178f0925504d94d8e79a5cc281d83

Those are the changes necessary to integrate the slope bias. Ill give it a try as soon as I have some free time.

Charles · May 7, 2019, 3:20pm

Hi,

Sorry for a long delay and lack of responses in this thread.

During the past weeks, we tried to address a few concerns raised in this thread regarding self-shadowing/shadow-acne. We added two simple mechanisms for that: slope bias (during shadow map rendering), and receiver bias (during the shadow-map fetching). The slope bias is directly controllable per light, and is proportional to the constant bias. With these two parameters in hand (constant bias + slope bias), you should be able to reduce some of the artifacts mentioned in this thread. Receiver bias is setup globally per light types. All types of bias (constant, slope, and receiver) are controllable through global variable per type of lights. These shadow improvements are in final stage of development and will be released with UE4.23

The well-criticized sphere should now appear smoother:

This should also allow to bring a bit more contact without introducing acne (with manual tweaking).

Please bare in mind, these improvements will help but won’t solve all your shadowing issues. Shadow maps are hard unfortunately.

II_ADN_II · May 7, 2019, 7:07pm

Charles.D2:

Hi,

Sorry for a long delay and lack of responses in this thread.

During the past weeks, we tried to address a few concerns raised in this thread regarding self-shadowing/shadow-acne. We added two simple mechanisms for that: slope bias (during shadow map rendering), and receiver bias (during the shadow-map fetching). The slope bias is directly controllable per light, and is proportional to the constant bias. With these two parameters in hand (constant bias + slope bias), you should be able to reduce some of the artifacts mentioned in this thread. Receiver bias is setup globally per light types. All types of bias (constant, slope, and receiver) are controllable through global variable per type of lights. These shadow improvements are in final stage of development and will be released with UE4.23

The well-criticized sphere should now appear smoother:

{“alt”:“Click image for larger version Name: 1.png Views: 2 Size: 184.0 KB ID: 1616438”,“data-align”:“none”,“data-attachmentid”:“1616438”,“data-size”:“full”}

{“alt”:“Click image for larger version Name: 2.png Views: 1 Size: 383.8 KB ID: 1616436”,“data-align”:“none”,“data-attachmentid”:“1616436”,“data-size”:“full”}

This should also allow to bring a bit more contact without introducing acne (with manual tweaking).

{“alt”:“Click image for larger version Name: 3.png Views: 3 Size: 284.5 KB ID: 1616440”,“data-align”:“none”,“data-attachmentid”:“1616440”,“data-size”:“medium”}

Please bare in mind, these improvements will help but won’t solve all your shadowing issues. Shadow maps are hard unfortunately.

Thank god this will be in 2.23 T_T Thank you very much, this problem was killing the usability of realtime shadows. Cant wait to test it on 2.23, hope it work as good as other engines

PD: the difference in first image(ground specially) says it all

The_Distiller · May 7, 2019, 10:09pm

@Charles.D2: Will the new parameters help to improve landscape slopes as well?

XilenceX · May 7, 2019, 10:41pm

Charles.D2:

Hi,

Sorry for a long delay and lack of responses in this thread.

During the past weeks, we tried to address a few concerns raised in this thread regarding self-shadowing/shadow-acne. We added two simple mechanisms for that: slope bias (during shadow map rendering), and receiver bias (during the shadow-map fetching). The slope bias is directly controllable per light, and is proportional to the constant bias. With these two parameters in hand (constant bias + slope bias), you should be able to reduce some of the artifacts mentioned in this thread. Receiver bias is setup globally per light types. All types of bias (constant, slope, and receiver) are controllable through global variable per type of lights. These shadow improvements are in final stage of development and will be released with UE4.23

The well-criticized sphere should now appear smoother:

1.jpg800×359 35.2 KB

2.jpg800×385 57 KB

This should also allow to bring a bit more contact without introducing acne (with manual tweaking).

3.jpg800×655 47.2 KB

Please bare in mind, these improvements will help but won’t solve all your shadowing issues. Shadow maps are hard unfortunately.

I must be dreaming. Epic actually fixed self-shadowing/shadow-acne for dynamic shadows?!?
I’ve been hoping for more work being done on that since the Beta. So that finally actually happening in UE4.23 seems almost surreal.
Ofc. it won’t be perfect, but finally having dynamic shadows that at least look “good enough” would be a very big deal.
For high end PCs we might switch to RTX eventually, but the regular dynamic shadows will be the fallback for low end machines for a long time.