Geometric node UV calculation error #89888

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SensArice · 2021-07-16T05:33:37+02:00

SensArice commented

2021-07-16 05:33:37 +02:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: Quadro RTX 4000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 460.89

Blender Version

Broken: version: 2.93.1, branch: master, commit date: 2021-06-22 05:57, hash: 1b8d33b18c
Worked: (newest version of Blender that worked as expected)

Short description of error
[Please fill out a short description of the error here]

Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]

2021-07-16 11-30-00.mp4

untitled.blend

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: Quadro RTX 4000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 460.89 **Blender Version** Broken: version: 2.93.1, branch: master, commit date: 2021-06-22 05:57, hash: `1b8d33b18c` Worked: (newest version of Blender that worked as expected) **Short description of error** [Please fill out a short description of the error here] **Exact steps for others to reproduce the error** [Please describe the exact steps needed to reproduce the issue] [Based on the default startup or an attached .blend file (as simple as possible)] [2021-07-16 11-30-00.mp4](https://archive.blender.org/developer/F10225628/2021-07-16_11-30-00.mp4) [untitled.blend](https://archive.blender.org/developer/F10225629/untitled.blend)

SensArice commented

2021-07-16 05:33:37 +02:00

Added subscriber: @SensArice

SensArice commented

2021-07-16 05:34:49 +02:00

The values are the same, but display and rendering errors

SensArice commented

2021-07-16 05:39:52 +02:00

what？one attribute and two attribute Different？

![QQ截图20210716113647.png](https://archive.blender.org/developer/F10225630/QQ截图20210716113647.png) what？one attribute and two attribute Different？

Philipp Oeser commented

2021-07-23 16:56:10 +02:00

Added subscribers: @HooglyBoogly, @JacquesLucke, @lichtwerk

Philipp Oeser commented

2021-07-23 16:56:10 +02:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Philipp Oeser commented

2021-07-23 16:56:10 +02:00

In #89888#1191899, @SensArice wrote:

what？one attribute and two attribute Different？

Yep, you have to do your manipulations on the temporary vector/attribute and only in the end write back to UVMap as a 2DVector.
Not sure about the internals, but I assume you should never write with the usual attribute nodes (it all turns into 3DVectors) to the 2D UV directly (only after explicit conversion to 2D -- in the end usually).

@JacquesLucke , @HooglyBoogly this is expected behavor, right?

> In #89888#1191899, @SensArice wrote: > ![QQ截图20210716113647.png](https://archive.blender.org/developer/F10225630/QQ截图20210716113647.png) > > what？one attribute and two attribute Different？ Yep, you have to do your manipulations on the temporary vector/attribute and only in the end write back to UVMap as a 2DVector. Not sure about the internals, but I assume you should never write with the usual attribute nodes (it all turns into 3DVectors) to the 2D UV directly (only after explicit conversion to 2D -- in the end usually). @JacquesLucke , @HooglyBoogly this is expected behavor, right?

Philipp Oeser commented

2021-07-23 17:09:12 +02:00

Note sure if has the same roots as #85962 (Many Nodes (Join geometry, Boolean, Object Info?) and realizing instances remove UVs (output float2, not MLoopUV).).

Hans Goudey commented

2021-07-23 17:45:21 +02:00

It's a bit different than that other task. The main issue here is that we don't have nodes that can write to 2D vectors, or 2D vectors as a socket type. I think we should do all of that at some point, maybe as part of a larger effort at making geometry nodes work better for UVs/2D vectors.

Philipp Oeser commented

2021-07-23 18:18:14 +02:00

In #89888#1195497, @HooglyBoogly wrote:
It's a bit different than that other task. The main issue here is that we don't have nodes that can write to 2D vectors

Well, the Attribute Convert with Type 2D Vector can, and it works perfectly fine (as long as you dont dare writing to UVs without it or prior to it).
This works in rendering as well (that is why I am also a bit confused why this is not also possible internally for #85962?)

> In #89888#1195497, @HooglyBoogly wrote: > It's a bit different than that other task. The main issue here is that we don't have nodes that can write to 2D vectors Well, the `Attribute Convert` with Type `2D Vector` can, and it works perfectly fine (as long as you dont dare writing to UVs without it or prior to it). This works in rendering as well (that is why I am also a bit confused why this is not also possible internally for #85962?)

Jacques Lucke commented

2021-11-03 13:13:59 +01:00

I think this is in fact a duplicate of #85962. Fortunately, there is an easy workaround now. Instead of using the UV Map node in the shader, just use an Attribute node.

Jacques Lucke commented

2021-11-03 13:14:06 +01:00

Closed as duplicate of #85962

Jacques Lucke closed this issue

2021-11-03 13:14:06 +01:00

Jan Kadeřábek commented

2021-11-03 14:11:22 +01:00

Added subscriber: @JanKaderabek

Jan Kadeřábek commented

2021-11-03 14:11:22 +01:00

@HooglyBoogly @JacquesLucke
Guys please stop saying using Attribute node in a shader is a workaround, because it is not - this is not just about being able to render the resulted mesh in Blender, but about preventing all the mesh data so it can be for example exported into another tool / game-engine etc.
Also many addons relies on custom shaders which can work only with UV Maps (and other legacy data), then this "workaround" won't work at all.

@HooglyBoogly @JacquesLucke Guys please stop saying using Attribute node in a shader is a workaround, because it is not - this is not just about being able to render the resulted mesh in Blender, but about preventing all the mesh data so it can be for example exported into another tool / game-engine etc. Also many addons relies on custom shaders which can work only with UV Maps (and other legacy data), then this "workaround" won't work at all.

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Geometric node UV calculation error #89888