Normal Map issues in Eevee - Backside Illuminated instead of front #64219

New Issue

Damon Bell · 2019-05-06T21:55:59+02:00

Damon Bell commented

2019-05-06 21:55:59 +02:00

System Information
Operating system: Windows 10
Graphics card: Nvidia GTX 1070

Blender Version
Broken: 2.80, a23647e51b, beta, 2019-05-06
Worked: (optional)

Short description of error
At certain lighting angles when using normal maps, illumination is transferred away from the front side of the mesh and the back side of the mesh becomes illuminated instead. It starts to become fairly noticeable at 0.2 strength for the normals. At a strength of 1.0, part of the front of the mesh become completely black and the backside of the mesh is fully illuminate underneath. All lamp types appear to be affected by this. HDRI seems to be doing some similar thing to but the maps don't go black. However, with HDRI, the backside of the mesh still becomes illuminated and appears to have some effect ton the front side results.

Exact steps for others to reproduce the error
This is very repeatable no my system and seems to affect all textures. I am using Poliigon.com textures.
See the video I recorded at this link which shows the issue.

https://www.youtube.com/watch?v=NLA1JQEd4BM

Here is a link to the blend file (does not contain the texture files). It was using the Hickory Wood Floor #2 for Poliigon. However, all textures react the same.
https://pixnub.com/downloads/test4.blend

**System Information** Operating system: Windows 10 Graphics card: Nvidia GTX 1070 **Blender Version** Broken: 2.80, a23647e51b10, beta, 2019-05-06 Worked: (optional) **Short description of error** At certain lighting angles when using normal maps, illumination is transferred away from the front side of the mesh and the back side of the mesh becomes illuminated instead. It starts to become fairly noticeable at 0.2 strength for the normals. At a strength of 1.0, part of the front of the mesh become completely black and the backside of the mesh is fully illuminate underneath. All lamp types appear to be affected by this. HDRI seems to be doing some similar thing to but the maps don't go black. However, with HDRI, the backside of the mesh still becomes illuminated and appears to have some effect ton the front side results. **Exact steps for others to reproduce the error** This is very repeatable no my system and seems to affect all textures. I am using Poliigon.com textures. See the video I recorded at this link which shows the issue. https://www.youtube.com/watch?v=NLA1JQEd4BM Here is a link to the blend file (does not contain the texture files). It was using the Hickory Wood Floor #2 for Poliigon. However, all textures react the same. https://pixnub.com/downloads/test4.blend

Damon Bell commented

2019-05-06 21:55:59 +02:00

Added subscriber: @ddbell23

Damon Bell changed title from ~~Normal Map issues in Eevee~~ to Normal Map issues in Eevee - Backside Illuminated instead of front

2019-05-06 22:01:05 +02:00

Marco commented

2019-05-06 23:19:25 +02:00

Added subscriber: @nacioss

Marco commented

2019-05-06 23:19:25 +02:00

I get this. Please can you pack the textures into the blend?

I get this. Please can you pack the textures into the blend? ![Screenshot.jpg](https://archive.blender.org/developer/F7010844/Screenshot.jpg)

Damon Bell commented

2019-05-07 14:21:12 +02:00

Here is a packed blend file. Note: this is using a different texture than the video.

https://pixnub.com/downloads/normal-map-test.blend

Here is a packed blend file. Note: this is using a different texture than the video. https://pixnub.com/downloads/normal-map-test.blend

Damon Bell commented

2019-05-07 17:47:48 +02:00

Another update. It looks like this issue only affects 16bit normal maps. See this video. It works fine with the 8 bit normal map but not with the 16 bit normal map (same exact map just 8 bit vs. 16 bit). I tested many textures and they all do the same thing.

Also, even with 8 bit, there still some illumination that can be seen on the backside of the mesh when viewing at a low angle.

https://www.youtube.com/watch?v=L0CUihAtRIY

Another update. It looks like this issue only affects 16bit normal maps. See this video. It works fine with the 8 bit normal map but not with the 16 bit normal map (same exact map just 8 bit vs. 16 bit). I tested many textures and they all do the same thing. Also, even with 8 bit, there still some illumination that can be seen on the backside of the mesh when viewing at a low angle. https://www.youtube.com/watch?v=L0CUihAtRIY

Damon Bell commented

2019-05-09 16:30:52 +02:00

See this latest video. When using 16-bit normal maps in Eevee it looks almost like it is treating it as "color data" instead of "non-color data".

https://www.youtube.com/watch?v=mZs6l5BM0M4

See this latest video. When using 16-bit normal maps in Eevee it looks almost like it is treating it as "color data" instead of "non-color data". https://www.youtube.com/watch?v=mZs6l5BM0M4

Marco commented

2019-05-19 19:15:32 +02:00

It is working in today's 2019-05-19 build. Can you confirm?

It is working in today's 2019-05-19 build. Can you confirm? ![Screenshot.jpg](https://archive.blender.org/developer/F7049226/Screenshot.jpg)

Damon Bell commented

2019-05-19 21:28:58 +02:00

Yes it works, thanks! :)

I tested both 8 bit and 16 bit and both work.

Yes it works, thanks! :) I tested both 8 bit and 16 bit and both work.

Marco commented

2019-05-19 21:29:46 +02:00

Changed status from 'Open' to: 'Resolved'

Marco closed this issue

2019-05-19 21:29:46 +02:00

Marco self-assigned this 2019-05-19 21:29:46 +02:00

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Normal Map issues in Eevee - Backside Illuminated instead of front #64219