Reflection Plane partially missing reflections in EEVEE #77658

New Issue

Cycles · 2020-06-09T02:47:09+02:00

Cycles commented

2020-06-09 02:47:09 +02:00

System Information
Operating system: Microsoft WIndows 10 Pro
Graphics card: Nvidia GeForce GTX 1050
Processor: Intel(R) Core(TM) i5-2500 CPU @ 3.30GHz, 3301 Mhz, 4 Core(s), 4 Logical Processor(s)

Blender Version
Broken: 2.91.0 Hash: 2c317457cb

Short description of error
On a glossy surface, reflections are partially missing when using a reflection plane with SSR on a flat surface. When adding a slight bumpiness with the bump node, the problem disappears. Also, increasing roughness slightly or rotating the reflection plane by a tiny amount (by even a fraction of a degree) also makes the artifacts invisible. missingreflections.blend

Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).
Open .blend file
Set to rendered view
Notice incomplete reflections
Set bump to non-zero value
Notice the issue goes away

**System Information** Operating system: Microsoft WIndows 10 Pro Graphics card: Nvidia GeForce GTX 1050 Processor: Intel(R) Core(TM) i5-2500 CPU @ 3.30GHz, 3301 Mhz, 4 Core(s), 4 Logical Processor(s) **Blender Version** Broken: 2.91.0 Hash: 2c317457cbf2 **Short description of error** On a glossy surface, reflections are partially missing when using a reflection plane with SSR on a flat surface. When adding a slight bumpiness with the bump node, the problem disappears. Also, increasing roughness slightly or rotating the reflection plane by a tiny amount (by even a fraction of a degree) also makes the artifacts invisible. [missingreflections.blend](https://archive.blender.org/developer/F8602876/missingreflections.blend) ![flat.JPG](https://archive.blender.org/developer/F8602871/flat.JPG) ![bumpy.JPG](https://archive.blender.org/developer/F8602870/bumpy.JPG) **Exact steps for others to reproduce the error** Based on the default startup or an attached .blend file (as simple as possible). Open .blend file Set to rendered view Notice incomplete reflections Set bump to non-zero value Notice the issue goes away

Cycles commented

2020-06-09 02:47:09 +02:00

Added subscriber: @Cycles

blender-admin commented

2020-06-09 02:47:09 +02:00

#73123 was marked as duplicate of this issue

Philipp Oeser commented

2020-06-09 14:07:05 +02:00

Added subscribers: @fclem, @lichtwerk

Philipp Oeser commented

2020-06-09 14:07:05 +02:00

Tbh, I dont really get how SSR and the reflection plane work together here.

From https://docs.blender.org/manual/en/2.83/render/eevee/light_probes/reflection_planes.html:

If Screen Space Reflection is enabled, Reflection Planes will serve as support buffers. This accelerates the tracing process and completes the missing data from the view space. This also make reflection more correct for the affected surfaces that have medium roughness and disturbed normals (i.e. normal maps).

When I look at the scene here the SSR should basically return nothing since relected walls are out of camera [unless you are really zoomed out far in the viewport and thus have massive overscan]
The less overscan you have the less glitches there will be in the viewport, so zooming in in this file actually reduces the "issue".
Also seems like F12 renders are not affected [kind of makes sense since there is no overscan]

maybe @fclem: knows better? (I assume this is not a bug, however it seems weird...)

Tbh, I dont really get how SSR and the reflection plane work together here. From https://docs.blender.org/manual/en/2.83/render/eevee/light_probes/reflection_planes.html: > If Screen Space Reflection is enabled, Reflection Planes will serve as support buffers. This accelerates the tracing process and completes the missing data from the view space. This also make reflection more correct for the affected surfaces that have medium roughness and disturbed normals (i.e. normal maps). When I look at the scene here the SSR should basically return nothing since relected walls are out of camera [unless you are really zoomed out far in the viewport and thus have massive overscan] The less overscan you have the less glitches there will be in the viewport, so zooming in in this file actually reduces the "issue". Also seems like F12 renders are not affected [kind of makes sense since there is no overscan] maybe @fclem: knows better? (I assume this is not a bug, however it seems weird...)

Cycles commented

2020-06-09 15:00:57 +02:00

One thing I notice is that the missing pieces of the reflection jitter wildly as the view changes. F12 renders are still getting these issues at certain viewpoints.

Even with SSR on any screen space reflections are typically overridden by the reflection plane's data I believe so I don't see why overscan would really affect the reflections. In fact, there seem to be more artifacts when zoomed in, but the issue does only occur when SSR is on for some reason.

One thing I notice is that the missing pieces of the reflection jitter wildly as the view changes. F12 renders are still getting these issues at certain viewpoints. Even with SSR on any screen space reflections are typically overridden by the reflection plane's data I believe so I don't see why overscan would really affect the reflections. In fact, there seem to be more artifacts when zoomed in, but the issue does only occur when SSR is on for some reason.

Jeran commented

2020-06-09 15:59:12 +02:00

Added subscriber: @TheJeran

Jeran commented

2020-06-09 15:59:12 +02:00

Turn SSR off for perfect reflection plane. For some reason when they work together it causes glitchiness. Especially when change changing perspective.

Cycles commented

2020-06-09 20:17:11 +02:00

In #77658#949943, @TheJeran wrote:
Turn SSR off for perfect reflection plane. For some reason when they work together it causes glitchiness. Especially when change changing perspective.

It would be a shame if screen space reflections and reflection planes cannot be used at the same time. I am not sure why this happens but hopefully there is a solution.

> In #77658#949943, @TheJeran wrote: > Turn SSR off for perfect reflection plane. For some reason when they work together it causes glitchiness. Especially when change changing perspective. It would be a shame if screen space reflections and reflection planes cannot be used at the same time. I am not sure why this happens but hopefully there is a solution.

Philipp Oeser commented

2020-06-11 15:00:45 +02:00

Changed status from 'Needs Triage' to: 'Confirmed'