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Eevee mipmaps not respecting border mode
Confirmed, NormalPublic

Description

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 432.00

Blender Version
Broken: version: 2.82 (sub 7), branch: master, commit date: 2020-02-12 16:20, hash: rB77d23b0bd76f
Also broken 2.83 alpha hash f6d5a9551380

Short description of error
Mipmaps used by Eevee appear to always be generated using tiling border mode, as if texture access mode is just set by modulo coordinates rather than setting the border sampling mode for the hardware.

This is true for both extend and clip modes of texture access.

I can't currently select Cycles rendering engine in 2.82 (presumably a different bug) but the problem doesn't exist in Cycles in 2.83 alpha or in previous versions where I've seen this bug (2.81 and 2.80 if I remember correctly), only in Eevee.

Exact steps for others to reproduce the error

Attached file demonstrates the bug. A plane with a magenta->black gradient texture is set to clip mode. You may need to zoom out to get a visible mipmap demonstrating the problem, as the mipmap chosen should depend on your own personal resolution.

Change to rendered view. At a suitable zoom, a magenta bar is visible on the rightmost margin of the plane.

Event Timeline

Since this could potentially be related to specific hardware, here's a screenshot:

Also shows up in renders:

Richard Antalik (ISS) changed the task status from Needs Triage to Confirmed.Feb 18 2020, 11:50 AM

Seems to happen only with linear interpolation in texture node.

I'm not sure why it behaves as it does, but it does look wrong. I can also confirm that it works as expected in Cycles.

Extra info: problem exists regardless of linear, cubic, or smart filtering. No problem, of course, with closest (no mip) filtering.