Stacking point distribute : repetitive distribution #90359

New Issue

Jules M. · 2021-08-01T21:39:15+02:00

Jules M. commented

2021-08-01 21:39:15 +02:00

System Information
Operating system: Windows 10
Graphics card: NVIDIA GTX 1080

Blender Version
Broken: 2.93.1
Worked: /

Short description of error
When stacking point distribute nodes I noticed that the scattering done by the second node is repeated on the instances.

Using Geometry nodes I setup the following model :

(point distribute > point instance > point distribute > point instance)
From this node setup one would expect it to behave as if the output of the 1st distribute+instance was the input mesh and thus have a different distribution for on each scattered object.
Here, for every object placed by the first distribute+instance, the distribution of objects (second distribute+instance) is similar.

as follows :

If this is normal behavior, how can it be circumvented to get the expected behavior ?

Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).
distribute_stacking.blend

Thank you for your amazing work

**System Information** Operating system: Windows 10 Graphics card: NVIDIA GTX 1080 **Blender Version** Broken: 2.93.1 Worked: / **Short description of error** When stacking point distribute nodes I noticed that the scattering done by the second node is repeated on the instances. Using Geometry nodes I setup the following model : ![Screenshot 2021-08-01 210639.png](https://archive.blender.org/developer/F10253767/Screenshot_2021-08-01_210639.png) (point distribute > point instance > point distribute > point instance) From this node setup one would expect it to behave as if the output of the 1st distribute+instance was the input mesh and thus have a different distribution for on each scattered object. Here, for every object placed by the first distribute+instance, the distribution of objects (second distribute+instance) is similar. as follows : ![Screenshot 2021-08-01 211304.png](https://archive.blender.org/developer/F10253783/Screenshot_2021-08-01_211304.png) If this is normal behavior, how can it be circumvented to get the expected behavior ? **Exact steps for others to reproduce the error** Based on the default startup or an attached .blend file (as simple as possible). [distribute_stacking.blend](https://archive.blender.org/developer/F10253780/distribute_stacking.blend) Thank you for your amazing work

Jules M. commented

2021-08-01 21:39:15 +02:00

Added subscriber: @ogjee

Jules M. commented

2021-08-02 11:58:38 +02:00

Removed subscriber: @ogjee

Miro Horváth commented

2021-08-02 13:56:20 +02:00

Added subscribers: @ogjee, @MiroHorvath

Miro Horváth commented

2021-08-02 13:56:20 +02:00

@ogjee As far as I remember this is a known issue. The setup you used suffers from the fact that you're scattering directly on instances(second Point Distribute node)...

...and that causes randomization to be the same for each instance.
A temporary workaround is to "realize"(convert) instances to a mesh eg. by creating a new attribute, after this node instances become a mesh again and scattering then happens on a mesh(all cubes scattered with first Point Distribute node)

This unfortunately has the down side that you lose possibility to control density on each previous instance as scattering is happening on the mesh as a whole.
You'll understand better if you play with it yourself, here's the example.
distribute_stacking.blend

@ogjee As far as I remember this is a known issue. The setup you used suffers from the fact that you're scattering directly on instances(second Point Distribute node)... ![image.png](https://archive.blender.org/developer/F10259684/image.png) ...and that causes randomization to be the same for each instance. A temporary workaround is to "realize"(convert) instances to a mesh eg. by creating a new attribute, after this node instances become a mesh again and scattering then happens on a mesh(all cubes scattered with first Point Distribute node) ![image.png](https://archive.blender.org/developer/F10259696/image.png) This unfortunately has the down side that you lose possibility to control density on each previous instance as scattering is happening on the mesh as a whole. You'll understand better if you play with it yourself, here's the example. [distribute_stacking.blend](https://archive.blender.org/developer/F10259707/distribute_stacking.blend)

Richard Antalik commented

2021-08-06 01:19:00 +02:00

Added subscriber: @iss

Richard Antalik commented

2021-08-06 01:19:00 +02:00

Changed status from 'Needs Triage' to: 'Archived'

Richard Antalik closed this issue

2021-08-06 01:19:00 +02:00

Richard Antalik commented

2021-08-06 01:19:00 +02:00

Thanks @MiroHorvath for providing explanation and workaround.
I will add, that for support or workflow issues please use one of the community websites: https://www.blender.org/community/

Closing, as this is works as intended.

Thanks @MiroHorvath for providing explanation and workaround. I will add, that for support or workflow issues please use one of the community websites: https://www.blender.org/community/ Closing, as this is works as intended.

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Stacking point distribute : repetitive distribution #90359