Particles from multiple systems disappear when all Physics Type are None. #72223

New Issue

Vogel Tobias · 2019-12-06T08:25:11+01:00

Vogel Tobias commented

2019-12-06 08:25:11 +01:00

System Information
Operating system: Windows 10
Graphics card: RTX 2070

Blender Version
Broken: 2.81a

Short description of error
When selecting a Particle System, all particles of the object disappear.
Images showing before and after:

Exact steps for others to reproduce the error

In the default cube add two particle systems.
Set the Frame End of both to 1 for better observation.
In the Physics tab of both choose Physics Type None.
Select any of the particle systems, note that the particles disappear.

Attached file contains an example of multiple particle system on one object:
LP_grass.blend

This has to be the first file you open with the application.
If you open blender and enable the eevee material preview for example with the default cube and open the example file afterwards it works.

**System Information** Operating system: Windows 10 Graphics card: RTX 2070 **Blender Version** Broken: 2.81a **Short description of error** When selecting a Particle System, all particles of the object disappear. Images showing before and after: ![steps.jpg](https://archive.blender.org/developer/F8193158/steps.jpg) ![steps2.jpg](https://archive.blender.org/developer/F8193171/steps2.jpg) **Exact steps for others to reproduce the error** - In the default cube add two particle systems. - Set the `Frame End` of both to 1 for better observation. - In the `Physics` tab of both choose `Physics Type` `None`. - Select any of the particle systems, note that the particles disappear. Attached file contains an example of multiple particle system on one object: [LP_grass.blend](https://archive.blender.org/developer/F8193146/LP_grass.blend) This has to be the first file you open with the application. If you open blender and enable the eevee material preview for example with the default cube and open the example file afterwards it works.

Vogel Tobias commented

2019-12-06 08:25:11 +01:00

Added subscriber: @voto

Vogel Tobias changed title from ~~Eevee Rendered and material preview display glitch with multiple Particle Systems~~ to Material preview and selection glitch with multiple Particle Systems

2019-12-07 06:11:08 +01:00

Germano Cavalcante commented

2019-12-11 13:35:43 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2019-12-11 13:35:43 +01:00

I can confirm.
The problem is also seen in 2.80 and is related to the Physics Type None in all the particle systems.

I can confirm. The problem is also seen in 2.80 and is related to the `Physics Type` `None` in all the particle systems.

Germano Cavalcante changed title from ~~Material preview and selection glitch with multiple Particle Systems~~ to Particles from multiple systems disappear when all Physics Type are None.

2019-12-11 18:05:52 +01:00

Germano Cavalcante commented

2019-12-11 18:38:10 +01:00

Added subscriber: @Sergey

Germano Cavalcante commented

2019-12-11 18:38:10 +01:00

@Sergey, I'm not sure, but it seems that in this case ob->particlesystem is not being tagged to be updated. (Related to depsgraph?)
If you notice, the variable psys in particle_batch_cache_ensure_pos is almost blank. As if the values have not yet been set.

Would you mind taking a look at this?

@Sergey, I'm not sure, but it seems that in this case `ob->particlesystem` is not being tagged to be updated. (Related to depsgraph?) If you notice, the variable `psys` in `particle_batch_cache_ensure_pos` is almost blank. As if the values have not yet been set. Would you mind taking a look at this?

Dalai Felinto commented

2019-12-11 19:51:32 +01:00

Added subscriber: @dfelinto

Sergey Sharybin commented

2019-12-12 08:50:34 +01:00

Object::particlesystem is a list of particle systems and tagging is only happening on an ID level.

If there is a missing ID tag that'd be some-non-depsgraph-code related issue.
If there is an ID tag happening and particle_system_update is called then the issue is somewhere is in the particle code (or, figuring out what got lost somewhere is easier from there).
If there is ID tag for geometry update and particle_system_update is not called then the issue is indeed in the dependency graph.

`Object::particlesystem` is a list of particle systems and tagging is only happening on an ID level. If there is a missing ID tag that'd be some-non-depsgraph-code related issue. If there is an ID tag happening and `particle_system_update` is called then the issue is somewhere is in the particle code (or, figuring out what got lost somewhere is easier from there). If there is ID tag for geometry update and `particle_system_update` is not called then the issue is indeed in the dependency graph.

Tomasz Kaye commented

2020-09-10 20:54:25 +02:00

Added subscriber: @info-27

Philipp Oeser removed the

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Particles from multiple systems disappear when all Physics Type are None. #72223