Maniphest T96061

UV tangents not seamless
Closed, Duplicate
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Assigned To
None
Authored By
tempdevnova (tempdevnova)
Feb 27 2022, 4:58 PM
Tags
  • BF Blender
Subscribers
Germano Cavalcante (mano-wii)
Pratik Borhade (PratikPB2123)
tempdevnova (tempdevnova)

Description

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 431.07

Blender Version
Broken: version: 3.0.0, branch: master, commit date: 2021-12-02 18:35, hash: rBf1cca3055776
Worked: (newest version of Blender that worked as expected)

Short description of error
When using a UV map with the tangent node the resulting tangent sometimes isn't seamless although it should be.

Exact steps for others to reproduce the error

Test file:

Tangent test file.blend848 KBDownload

When looking at the mesh and UV map it is apparent that the resulting tangents should look like that of the tangent node when set to radial Z, but it doesn't.

Thank you and have a great day.

Related Objects

Event Timeline

tempdevnova (tempdevnova) created this task.Feb 27 2022, 4:58 PM
Pratik Borhade (PratikPB2123) added a subscriber: Pratik Borhade (PratikPB2123).Feb 28 2022, 7:23 AM
Germano Cavalcante (mano-wii) added a subscriber: Germano Cavalcante (mano-wii).Mar 1 2022, 7:16 PM

I'm pretty sure this is a result of the problem described in T80253: Cylinder smooth shading issue.
Basically, the problem is a limitation of the geometries that work with triangles.
The UVs interpolation is done on the triangles and not uniformly on the polygon.

You can better understand the problem with this image:

This is something the developers are aware of and unfortunately has no simple fix.
You can edit the geometry to work around the problem.

Germano Cavalcante (mano-wii) closed this task as a duplicate of T80253: Cylinder smooth shading issue.Mar 1 2022, 7:16 PM
tempdevnova (tempdevnova) added a comment.Mar 2 2022, 4:24 PM

Im pretty sure that is not the case, because in the case of tangents it doesn't matter whether the mesh is triangulated or not.