Odd sharp highlights in Eevee. #60997

New Issue

Piotr Adamowicz · 2019-01-29T20:47:30+01:00

Piotr Adamowicz commented

2019-01-29 20:47:30 +01:00

System Information
Operating system: Windows 10
Graphics card: GF 1080Ti, latest drivers

Blender Version
Broken: 2.80 beta, 2019-01-29, Buildbot
Worked: ?

Short description of error
Odd highlights appear in Eevee

Exact steps for others to reproduce the error

Open attached .blend file
Set view to 'rendered' mode
See odd sharp highlights on areas roughly perpendicular to the light, marked with grease pencil

shading.blend

**System Information** Operating system: Windows 10 Graphics card: GF 1080Ti, latest drivers **Blender Version** Broken: 2.80 beta, 2019-01-29, Buildbot Worked: ? **Short description of error** Odd highlights appear in Eevee **Exact steps for others to reproduce the error** 1. Open attached .blend file 2. Set view to 'rendered' mode 3. See odd sharp highlights on areas roughly perpendicular to the light, marked with grease pencil [shading.blend](https://archive.blender.org/developer/F6445969/shading.blend)

Piotr Adamowicz commented

2019-01-29 20:47:30 +01:00

Added subscriber: @MadMinstrel

blender-admin commented

2019-01-29 20:47:30 +01:00

#61550 was marked as duplicate of this issue

Jacques Lucke commented

2019-01-30 15:01:36 +01:00

Added subscriber: @JacquesLucke

Jacques Lucke commented

2019-01-30 15:01:36 +01:00

I don't know what you mean, please post a screenshot.

I don't know what you mean, please post a screenshot. ![Screenshot from 2019-01-30 15-01-01.png](https://archive.blender.org/developer/F6453994/Screenshot_from_2019-01-30_15-01-01.png)

Piotr Adamowicz commented

2019-01-30 17:53:41 +01:00

My apologies, i should have posted a screenshot from the beginning.

My apologies, i should have posted a screenshot from the beginning. ![shading.jpg](https://archive.blender.org/developer/F6455255/shading.jpg)

Jacques Lucke commented

2019-01-30 17:56:32 +01:00

Added subscriber: @fclem

Jacques Lucke commented

2019-01-30 17:56:32 +01:00

@fclem, any idea what could cause this?

Emil commented

2019-02-25 20:32:53 +01:00

Added subscriber: @LightSmith

Emil commented

2019-02-25 20:32:53 +01:00

Exactly the same problem! Actually it's very noticeable bug(
Operating system: Windows 10
Graphics card: GTX 980
Blender version: 2.80, commit date: 2019-02-19 00:38, hash: 790cb7799d, build date: 18/02/2019, 18:07

There are only glossy sphere and a sun lamp. Unfortunately the bug is visible in different scenes if there are lamps there. More or less. In any scene with any type of lamps. It looks like a lot of fireflies on final renders.
Also it changes when zoom in and zoom out.
2.80_highlight_bug.blend

Exactly the same problem! Actually it's very noticeable bug( ![изображение.png](https://archive.blender.org/developer/F6713647/изображение.png) Operating system: Windows 10 Graphics card: GTX 980 Blender version: 2.80, commit date: 2019-02-19 00:38, hash: 790cb7799dcf, build date: 18/02/2019, 18:07 There are only glossy sphere and a sun lamp. Unfortunately the bug is visible in different scenes if there are lamps there. More or less. In any scene with any type of lamps. It looks like a lot of fireflies on final renders. Also it changes when zoom in ![изображение.png](https://archive.blender.org/developer/F6713681/изображение.png) and zoom out. ![изображение.png](https://archive.blender.org/developer/F6713679/изображение.png) [2.80_highlight_bug.blend](https://archive.blender.org/developer/F6713686/2.80_highlight_bug.blend)

Clément Foucault was assigned by Jacques Lucke

2019-02-26 13:47:21 +01:00

Jacques Lucke commented

2019-02-26 13:47:21 +01:00

Ah now I can reproduce this. It happens when the Roughness is very small. And Specular is greater than zero.

It happens on flat and smooth surfaces.

Ah now I can reproduce this. It happens when the `Roughness` is very small. And `Specular` is greater than zero. It happens on flat and smooth surfaces.

Clément Foucault commented

2019-03-08 16:01:29 +01:00

Added subscribers: @Zexyp, @ZedDB

Clément Foucault commented

2019-03-11 12:03:06 +01:00

Changed status from 'Open' to: 'Archived'

Clément Foucault closed this issue

2019-03-11 12:03:06 +01:00

Clément Foucault commented

2019-03-11 12:03:06 +01:00

Ok so after spending a lot of (too much?) time trying to find a solution, I can safely say it's a limitation of the algorithm used for area lighting (this is the same algorithm for all light types). Even the reference implementation of the algorithm suffers from the same artifacts.

The only workaround to this is to have proper shadowing (which is not great with the default setup).
Increasing the exponent for ESM shadow maps can help a bit but you loose smooth shadows.

Ok so after spending a lot of (too much?) time trying to find a solution, I can safely say it's a limitation of the algorithm used for area lighting (this is the same algorithm for all light types). Even the reference implementation of the algorithm suffers from the same artifacts. The only workaround to this is to have proper shadowing (which is not great with the default setup). Increasing the exponent for ESM shadow maps can help a bit but you loose smooth shadows.

Piotr Adamowicz commented

2019-03-11 12:25:32 +01:00

Thanks for looking into it. This is a pretty severe problem without an artist-side workaround, so is there any chance an alternative algorithm might be implemented down the line?

It's not always feasible or desirable to use shadows on every light due to shadow maps' problematic nature.

Thanks for looking into it. This is a pretty severe problem without an artist-side workaround, so is there any chance an alternative algorithm might be implemented down the line? It's not always feasible or desirable to use shadows on every light due to shadow maps' problematic nature.

Clément Foucault commented

2019-03-11 12:44:39 +01:00

@MadMinstrel unfortunately, there is no other method existing (that I know of that have acceptable quality). Using bruteforce sampling that would take ages to converge depending on the lamp size or using MIS but this is basically asking for Cycles inside Eevee.

Piotr Adamowicz commented

2019-03-11 13:11:32 +01:00

I see. That is unfortunate.

In that case, since this problem is here to stay, would it at least be possible to allow the user to separately set the radius/size used for illumination and the one used for soft shadows? That way the problem could at least be somewhat mitigated in cases where area-illumination isn't necessary and point-lights will do.

I see. That is unfortunate. In that case, since this problem is here to stay, would it at least be possible to allow the user to separately set the radius/size used for illumination and the one used for soft shadows? That way the problem could at least be somewhat mitigated in cases where area-illumination isn't necessary and point-lights will do.

Clément Foucault commented

2019-03-12 16:05:34 +01:00

In #60997#637397, @MadMinstrel wrote:
In that case, since this problem is here to stay, would it at least be possible to allow the user to separately set the radius/size used for illumination and the one used for soft shadows? That way the problem could at least be somewhat mitigated in cases where area-illumination isn't necessary and point-lights will do.

I don't like making the engine harder to use. Using a PBR approach is meant to simplify rendering. If we create many options it can really become a mess like BI was.

On the other hand, I wouldn't mind a global toggle to use a different algorithm or even point lights for that matter.

> In #60997#637397, @MadMinstrel wrote: > In that case, since this problem is here to stay, would it at least be possible to allow the user to separately set the radius/size used for illumination and the one used for soft shadows? That way the problem could at least be somewhat mitigated in cases where area-illumination isn't necessary and point-lights will do. I don't like making the engine harder to use. Using a PBR approach is meant to simplify rendering. If we create many options it can really become a mess like BI was. On the other hand, I wouldn't mind a global toggle to use a different algorithm or even point lights for that matter.

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Odd sharp highlights in Eevee. #60997