Maniphest T56458

Normal map shading errors in OpenGL
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Assigned To
Brecht Van Lommel (brecht)
Authored By
Jonas Pilo (ninthjake)
Aug 20 2018, 4:37 AM
Tags
  • BF Blender
Subscribers
Brecht Van Lommel (brecht)
Jonas Pilo (ninthjake)

Description

System Information
Windows 10 x64
AMD Radeon R9390X - Graphics card
AMD FX-8320 - CPU

Blender Version
Broken: All Blender versions

Short description of error
Adding a normal map to a model breaks the shading of the object.

Bug_report_Normal_maps.blend1 MBDownload

Exact steps for others to reproduce the error
Press "M" to toggle (mute/unmute) the normal map in the file and watch the shading change in the 3D view window.

Here is a video I recorded showing the problem in more detail.
youtube link

Related Objects

Event Timeline

Jonas Pilo (ninthjake) created this task.Aug 20 2018, 4:37 AM
Brecht Van Lommel (brecht) lowered the priority of this task from 90 to 30.EditedAug 20 2018, 11:20 AM
Brecht Van Lommel (brecht) added a subscriber: Brecht Van Lommel (brecht).

It's not clear to me what the bug is, muting the Normal Map node is supposed to change the shading. It is needed for converting the Tangent Space normal to a normal for shading, so if you skip that step the result will be wrong wrong.

The video shows a different .blend file so we can't test that. Can you attach the .blend file that has the bug and a render showing the wrong result it gives you?

Jonas Pilo (ninthjake) added a comment.Aug 20 2018, 9:57 PM
This comment was removed by Jonas Pilo (ninthjake).
Jonas Pilo (ninthjake) added a comment.Aug 21 2018, 10:38 PM
In T56458#528819, @Brecht Van Lommel (brecht) wrote:

It's not clear to me what the bug is, muting the Normal Map node is supposed to change the shading. It is needed for converting the Tangent Space normal to a normal for shading, so if you skip that step the result will be wrong wrong.

The video shows a different .blend file so we can't test that. Can you attach the .blend file that has the bug and a render showing the wrong result it gives you?

Sorry, my wording is bad. I know the shading is supposed to change but it looks like adding a normal map adds a layer of reflectivity to the model.

I cannot share the file I showed in the previous video but I put together a new file + video that much better shows the issue.

bugreport_normalmap02.blend83 KBDownload
(Open in Blender 2.8)
And here is how it looks for me

This time I simply just added a blank image as the normal map and plugged it into the standard Principled BSDF in Eevee on a default unwrapped cube.

Brecht Van Lommel (brecht) changed the task status from Unknown Status to Unknown Status.Aug 21 2018, 10:43 PM
Brecht Van Lommel (brecht) claimed this task.

This issue is the different color management settings in Cycles and Eevee. For Eevee / viewport you need to change the color space in the image editor to be Non-Color Data as well.

I've added it to the list of settings to unify in T54659.