Eevee: Soft shadows causing flickering in animation and temporal AA in scenes #68594

New Issue

Eric Klein · 2019-08-13T04:09:58+02:00

Eric Klein commented

2019-08-13 04:09:58 +02:00

System Information
Operating system: Windows-10-10.0.17134 64 Bits
Graphics card: GeForce RTX 2070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 435.80

Blender Version
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: f6cb5f5449
Worked: (optional)

Short description of error
Eevee soft shadows in objects with thin reflections causes flickering in animation and temporal AA in still images. This type reflections common in interior Arch Viz.

Exact steps for others to reproduce the error
Scene 1 example of flickering of soft shadows in animation. I have remove all light probes and effects to focus only light and shadows. Open attach file "Scene1_AA_eevee.blend".
Render the animation with Soft Shadows ON. Then Render animation with Soft Shadows OFF.
Scene1_AA_eevee.blend

Animation with Soft Shadows ON. Make sure to play video at full size. If not video will be alias by the video player.
Scene1_AA_eevee.mp4

Animation with Soft Shadows OFF. Make sure to play video at full size. If not video will be alias by the video player.
Scene1_AA_No_SShadow_eevee.mp4

Animation in Cycles for comparison. Make sure to play video at full size. If not video will be alias by the video player.
Scene1_AA_cycles.mp4

Scene 2 example of temporal anti-aliasing cause by soft shadows. I have simplify the scene 2 to focus only light and shadows. Open attach file "Scene2_AA_eevee.blend".
Render Image with Soft Shadows ON. Then Render Image with Soft Shadows OFF.
Scene2_AA_eevee.blend

Render image with Soft Shadows ON. Make sure to view at full size. Notice the temporal AA on the edges on horizontal counter, vertical counter, oven handle and oven racks.

Render image with Soft Shadows OFF. Make sure to view at full size. Notice the temporal AA is gone.

Render image with Cycles for comparison. Make sure to view at full size.

**System Information** Operating system: Windows-10-10.0.17134 64 Bits Graphics card: GeForce RTX 2070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 435.80 **Blender Version** Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: `f6cb5f5449` Worked: (optional) **Short description of error** Eevee soft shadows in objects with thin reflections causes flickering in animation and temporal AA in still images. This type reflections common in interior Arch Viz. **Exact steps for others to reproduce the error** Scene 1 example of flickering of soft shadows in animation. I have remove all light probes and effects to focus only light and shadows. Open attach file "Scene1_AA_eevee.blend". Render the animation with Soft Shadows ON. Then Render animation with Soft Shadows OFF. [Scene1_AA_eevee.blend](https://archive.blender.org/developer/F7661168/Scene1_AA_eevee.blend) Animation with Soft Shadows ON. Make sure to play video at full size. If not video will be alias by the video player. [Scene1_AA_eevee.mp4](https://archive.blender.org/developer/F7661169/Scene1_AA_eevee.mp4) Animation with Soft Shadows OFF. Make sure to play video at full size. If not video will be alias by the video player. [Scene1_AA_No_SShadow_eevee.mp4](https://archive.blender.org/developer/F7661170/Scene1_AA_No_SShadow_eevee.mp4) Animation in Cycles for comparison. Make sure to play video at full size. If not video will be alias by the video player. [Scene1_AA_cycles.mp4](https://archive.blender.org/developer/F7661177/Scene1_AA_cycles.mp4) ****************************************************************************************************** Scene 2 example of temporal anti-aliasing cause by soft shadows. I have simplify the scene 2 to focus only light and shadows. Open attach file "Scene2_AA_eevee.blend". Render Image with Soft Shadows ON. Then Render Image with Soft Shadows OFF. [Scene2_AA_eevee.blend](https://archive.blender.org/developer/F7661185/Scene2_AA_eevee.blend) Render image with Soft Shadows ON. Make sure to view at full size. Notice the temporal AA on the edges on horizontal counter, vertical counter, oven handle and oven racks. ![Scene2_AA_eevee.jpg](https://archive.blender.org/developer/F7661188/Scene2_AA_eevee.jpg) Render image with Soft Shadows OFF. Make sure to view at full size. Notice the temporal AA is gone. ![Scene2_AA_No_SShadows_eevee.jpg](https://archive.blender.org/developer/F7661192/Scene2_AA_No_SShadows_eevee.jpg) Render image with Cycles for comparison. Make sure to view at full size. ![Scene2_AA_cycles.jpg](https://archive.blender.org/developer/F7661194/Scene2_AA_cycles.jpg)

Eric Klein commented

2019-08-13 04:09:58 +02:00

Added subscriber: @eklein

blender-admin commented

2019-08-13 04:09:58 +02:00

#79310 was marked as duplicate of this issue

Eric Klein commented

2019-08-13 16:32:44 +02:00

Another test for "Scene1_AA_eevee". Render image frame 2 and frame 3 in different slots. Compare these two frames and notice how the highlight switches between edges. These is causing the flickering in animation. Render the image frames again with Soft Shadows OFF. Notice their is no highlight switches between edges.

Clément Foucault commented

2019-09-06 23:55:44 +02:00

Added subscriber: @fclem

Clément Foucault self-assigned this 2019-09-06 23:55:44 +02:00

Clément Foucault commented

2019-09-06 23:55:44 +02:00

Thanks for raising awareness. After investigating, it seems to be a correlation artifacts. The same random numbers are used for AA and soft shadows jitter.

Using sobol should fix this issue, but sufficient amount of samples would be required.

Thanks for raising awareness. After investigating, it seems to be a correlation artifacts. The same random numbers are used for AA and soft shadows jitter. Using sobol should fix this issue, but sufficient amount of samples would be required.

blender-admin commented

2019-09-07 00:44:07 +02:00

This issue was referenced by ed779333bb

This issue was referenced by ed779333bb82a483c3f7833b959610c08f0bacb7

Clément Foucault commented

2019-09-07 00:45:12 +02:00

Changed status from 'Open' to: 'Resolved'

Clément Foucault closed this issue

2019-09-07 00:45:12 +02:00

Clément Foucault commented

2019-09-07 01:29:25 +02:00

After trying Sobol, I settled on using a multiplicator to halton as the points are better distributed than Sobol (in my opinion).

@eklein feel free to reopen if it does not feels fixed to you.

After trying Sobol, I settled on using a multiplicator to halton as the points are better distributed than Sobol (in my opinion). @eklein feel free to reopen if it does not feels fixed to you.

Eric Klein commented

2019-09-09 23:04:31 +02:00

Changed status from 'Resolved' to: 'Open'

Eric Klein reopened this issue

2019-09-09 23:04:31 +02:00

Eric Klein commented

2019-09-09 23:04:31 +02:00

Clement great improvement in the temporal AA with soft shadows. In Scene2_AA the temporal AA is complete fix along as their is enough samples.

In Scene1 the flickering has being noticeably reduce, but their is still some flickering left. In "Scene1_AA_eevee" Render Animation to 100 frames and play the image sequence in the blender video editor make sure the fractional zoom is set to 1:1. Notice some flickering of the highlights.

Clement great improvement in the temporal AA with soft shadows. In Scene2_AA the temporal AA is complete fix along as their is enough samples. In Scene1 the flickering has being noticeably reduce, but their is still some flickering left. In "Scene1_AA_eevee" Render Animation to 100 frames and play the image sequence in the blender video editor make sure the fractional zoom is set to 1:1. Notice some flickering of the highlights.

Eric Klein commented

2019-09-16 02:59:25 +02:00

I did more testing on Scene1_AA flickering. To solve most flickering left I had to increase samples 1024 and the film increase "Filter Size" to 2.0 to soften the thin highlights.

It does look at this time the PCF shadows requires a lot of samples to solve the AA/flickering with thin highlights with some help by increasing the "Filter Size". This also increase rendering time considerably for animation.

I did more testing on Scene1_AA flickering. To solve most flickering left I had to increase samples 1024 and the film increase "Filter Size" to 2.0 to soften the thin highlights. It does look at this time the PCF shadows requires a lot of samples to solve the AA/flickering with thin highlights with some help by increasing the "Filter Size". This also increase rendering time considerably for animation.

Clément Foucault commented

2019-09-16 11:14:47 +02:00

I think it's more related to the de-correlation factor I applied on soft shadows sampling. The factor is ~1000 so maybe changing this factor may reduce convergence time. But it's a bit black magic at this point, it can work in some case and fail in others.

The difference with cycles is that cycles does the randomization per pixel so the perceived flickering is less intense. But EEVEE can't do that and you are left with bumping the sample count.

I think it's more related to the de-correlation factor I applied on soft shadows sampling. The factor is ~1000 so maybe changing this factor may reduce convergence time. But it's a bit black magic at this point, it can work in some case and fail in others. The difference with cycles is that cycles does the randomization per pixel so the perceived flickering is less intense. But EEVEE can't do that and you are left with bumping the sample count.

Clément Foucault was unassigned by Dalai Felinto

2019-12-23 16:33:19 +01:00

Clément Foucault commented

2020-01-27 16:16:52 +01:00

Unfortunately I don't have much of a solution here. So I'll left this open as known limitation.

Germano Cavalcante commented

2020-07-29 15:35:45 +02:00

Added subscribers: @istoltoto, @mano-wii

pistol ioan commented

2020-07-29 19:24:15 +02:00

In #68594#859951, @fclem wrote:
Unfortunately I don't have much of a solution here. So I'll left this open as known limitation.

Hey Clément,
Here is a solution I found for this flickering using another softwere,
Maybe you get an idea from this addon on how to solve this in future. At least in rendering as an option to denoise.

Here is a video test I made with a grass rendered in Eevee, with before and after apply this plugin.
https://www.youtube.com/watch?v=5utbCECHewA&feature=youtu.be

DE:Noise for Premiere
https://revisionfx.com/products/denoise/

https://player.vimeo.com/video/116886900?portrait=0

Grass (1).blend

> In #68594#859951, @fclem wrote: > Unfortunately I don't have much of a solution here. So I'll left this open as known limitation. Hey Clément, Here is a solution I found for this flickering using another softwere, Maybe you get an idea from this addon on how to solve this in future. At least in rendering as an option to denoise. Here is a video test I made with a grass rendered in Eevee, with before and after apply this plugin. https://www.youtube.com/watch?v=5utbCECHewA&feature=youtu.be DE:Noise for Premiere https://revisionfx.com/products/denoise/ https://player.vimeo.com/video/116886900?portrait=0 [Grass (1).blend](https://archive.blender.org/developer/F8729024/Grass__1_.blend)

Jacob Merrill commented

2020-07-29 21:52:56 +02:00

Added subscriber: @JacobMerrill-1

Jacob Merrill commented

2020-07-29 21:52:56 +02:00

is there a way to not use soft shadows, and apply a 2d filter to the shadow buffer?
like depth aware blur or something?

is there a way to not use soft shadows, and apply a 2d filter to the shadow buffer? like depth aware blur or something?

Philipp Oeser removed the

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Eevee: Soft shadows causing flickering in animation and temporal AA in scenes #68594