White Noise Glitch using Value Attribute of Particle Instances #85708

New Issue

Aaron Beller · 2021-02-16T18:37:10+01:00

Aaron Beller commented

2021-02-16 18:37:10 +01:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 970/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 456.71

Blender Version
Broken: version: 2.93.0 Alpha, branch: master, commit date: 2021-02-16 08:05, hash: 36814ddc94
Worked: (?)

Short description of error
The White Noise Texture (in 1D) does not display as expected using the Value Attribute of Particle Instances in both EEVEE and Cycles. Instead of showing a single random value or color on the surface of an instance there's a fuzzy mess of different values similar to the look of overlapping faces:

The issue also appears on non flat geometry not only on planes. The using the Index attribute shows the same result. It's the same on the current stable release (that being 2.91.2) and previous releases. I tried the same setup with a Noise Texture and it seems to work just fine:

Exact steps for others to reproduce the error

Choose any object as the emitter of a particle hair system.
Adjust the settings of the particle system to display the desired quantity of hairs
Add another object and add a Particle Instance Modifier to it
- under 'Object' set the emitter object
- check 'Create Along Paths'
- in the object data properties under vertex color create a new vertex color
- choose the same vertex color as the 'Value' data of the particle instance modifier under 'Layers'
use the created data as the name in the Attribute Node
connect any output of the Attribute Node to a White Noise Node set to '1D'
display the results
(same last 5 steps for Index Attribute)
ParticleInstanc_ValueAttributeBug.blend

Thank you so much for looking into it! And keep up the great work.

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: GeForce GTX 970/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 456.71 **Blender Version** Broken: version: 2.93.0 Alpha, branch: master, commit date: 2021-02-16 08:05, hash: `36814ddc94` Worked: (?) **Short description of error** The White Noise Texture (in 1D) does not display as expected using the Value Attribute of Particle Instances in both EEVEE and Cycles. Instead of showing a single random value or color on the surface of an instance there's a fuzzy mess of different values similar to the look of overlapping faces: ![ValueAttribute_WhiteNoise.jpg](https://archive.blender.org/developer/F9808947/ValueAttribute_WhiteNoise.jpg) The issue also appears on non flat geometry not only on planes. The using the Index attribute shows the same result. It's the same on the current stable release (that being 2.91.2) and previous releases. I tried the same setup with a Noise Texture and it seems to work just fine: ![ValueAttribute_NoiseTexture.jpg](https://archive.blender.org/developer/F9808958/ValueAttribute_NoiseTexture.jpg) **Exact steps for others to reproduce the error** - Choose any object as the emitter of a particle hair system. - Adjust the settings of the particle system to display the desired quantity of hairs - Add another object and add a Particle Instance Modifier to it - under 'Object' set the emitter object - check 'Create Along Paths' - in the object data properties under vertex color create a new vertex color - choose the same vertex color as the 'Value' data of the particle instance modifier under 'Layers' - use the created data as the name in the Attribute Node - connect any output of the Attribute Node to a White Noise Node set to '1D' - display the results (same last 5 steps for Index Attribute) [ParticleInstanc_ValueAttributeBug.blend](https://archive.blender.org/developer/F9808997/ParticleInstanc_ValueAttributeBug.blend) Thank you so much for looking into it! And keep up the great work.

Aaron Beller commented

2021-02-16 18:37:10 +01:00

Added subscriber: @AaronBeller

Charlie Jolly commented

2021-02-16 19:54:08 +01:00

Added subscriber: @CharlieJolly

Charlie Jolly commented

2021-02-16 19:54:08 +01:00

Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: Intel(R) HD Graphics 520 Intel 4.5.0 - Build 26.20.100.7870
Broken: version: 2.93.0 Alpha, branch: master, commit date: 2021-02-11 21:15, hash: 3fea77ceed

Confirmed using Cycles but not Eevee.

Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: Intel(R) HD Graphics 520 Intel 4.5.0 - Build 26.20.100.7870 Broken: version: 2.93.0 Alpha, branch: master, commit date: 2021-02-11 21:15, hash: `3fea77ceed` Confirmed using Cycles but not Eevee.

Charlie Jolly commented

2021-02-17 12:10:28 +01:00

Cycles:

OSL:

Eevee:

Cycles: ![image.png](https://archive.blender.org/developer/F9811848/image.png) OSL: ![image.png](https://archive.blender.org/developer/F9811851/image.png) Eevee: ![image.png](https://archive.blender.org/developer/F9811853/image.png)

Ankit Meel commented

2021-05-18 14:45:31 +02:00

Added subscriber: @ankitm

Ankit Meel commented

2021-05-18 14:45:31 +02:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Ankit Meel commented

2021-05-18 14:45:31 +02:00

Can redo overlapping faces on 5e67dcf3d2 with cycles.
Intel HD 6000, macOS 10.14
Also created a new file for sanity check.

Render Engine\ Creator	you ParticleInstanc_ValueAttributeBug.blend	me T85708_attempt_noise.blend
eevee
cycles

Can redo overlapping faces on 5e67dcf3d2c337c0d4b0fb71b3800bd219629e2e with cycles. Intel HD 6000, macOS 10.14 Also created a new file for sanity check. |Render Engine\ Creator | you [ParticleInstanc_ValueAttributeBug.blend](https://archive.blender.org/developer/F9808997/ParticleInstanc_ValueAttributeBug.blend) | me [T85708_attempt_noise.blend](https://archive.blender.org/developer/F10122453/T85708_attempt_noise.blend)| | -- | -- | -- | |eevee| ![image.png](https://archive.blender.org/developer/F10122357/image.png)|![image.png](https://archive.blender.org/developer/F10130230/image.png) | |cycles | ![image.png](https://archive.blender.org/developer/F10122463/image.png)|![image.png](https://archive.blender.org/developer/F10130223/image.png) |

Aaron Beller commented

2021-05-20 14:20:18 +02:00

Hello! I just opened your file with the most recent version. The Noise Texture is working as expected. That was never the issue for me. I just left it in there so one could compare. So let me clarify: It is only the White Noise Texture that still shows unexpected/glitchy results.

Ankit Meel commented

2021-05-20 15:54:57 +02:00

Changed status from 'Needs User Info' to: 'Confirmed'

Ankit Meel commented

2021-05-20 15:54:57 +02:00

Okay my bad. Also I rendered cycles one with low samples, so the glitches got lost in noise. Edited last comment.

Philipp Oeser removed the

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White Noise Glitch using Value Attribute of Particle Instances #85708