Particles cache ignores animated lifetime #80592

New Issue

Juan Gea · 2020-09-08T13:48:06+02:00

Juan Gea commented

2020-09-08 13:48:06 +02:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 451.67

Blender Version
Broken: version: 2.90.0, branch: master, commit date: 2020-08-31 11:26, hash: 0330d1af29
Worked: not sure if it worked after 2.80, maybe it worked in 2.79, but I'm not sure.

Short description of error
If you animate the lifetime and bake the particles everything in the same blender session everything works correctly, no matter if you bake them to disk or to memory.
When you save the file, and open the file again the particle cache is broken and it's loading all the animation with the lifetime present in the first frame, no matter if it's a disk cache or a memory cache.

Exact steps for others to reproduce the error

Blende file: test.blend

Steps to reproduce:

You can watch the video I did or follow this steps:

Video:particle_lifetime_an_bug.mp4

1.- Open the attached blend file with Blender 2.90 release
2.- Clean the cache if there is one, change some parameter like particle count (don't touch particle lifetime, it's animated)
3.- Bake the animation, and you will see the correct result
4.- create a new file
5.- reload our test file
6.- you will see how the cache is not behaving correctly and it's ignoring the animated lifetime

It's impossible to trustworthy bake particles without this working, because not even the disk cache is working

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 451.67 **Blender Version** Broken: version: 2.90.0, branch: master, commit date: 2020-08-31 11:26, hash: `0330d1af29` Worked: not sure if it worked after 2.80, maybe it worked in 2.79, but I'm not sure. **Short description of error** If you animate the lifetime and bake the particles everything in the same blender session everything works correctly, no matter if you bake them to disk or to memory. When you save the file, and open the file again the particle cache is broken and it's loading all the animation with the lifetime present in the first frame, no matter if it's a disk cache or a memory cache. **Exact steps for others to reproduce the error** Blende file: [test.blend](https://archive.blender.org/developer/F8854036/test.blend) Steps to reproduce: You can watch the video I did or follow this steps: Video:[particle_lifetime_an_bug.mp4](https://archive.blender.org/developer/F8854053/particle_lifetime_an_bug.mp4) 1.- Open the attached blend file with Blender 2.90 release 2.- Clean the cache if there is one, change some parameter like particle count (don't touch particle lifetime, it's animated) 3.- Bake the animation, and you will see the correct result 4.- create a new file 5.- reload our test file 6.- you will see how the cache is not behaving correctly and it's ignoring the animated lifetime It's impossible to trustworthy bake particles without this working, because not even the disk cache is working

Juan Gea commented

2020-09-08 13:48:06 +02:00

Added subscriber: @juang3d

Juan Gea commented

2020-09-08 14:15:02 +02:00

I suspect the problem is in the file:

Particle_System.c

In the line 1325:

void psys_get_pointcache_start_end(Scene *scene, ParticleSystem *psys, int *sfra, int *efra)
{
  ParticleSettings *part = psys->part;

  *sfra = max_ii(1, (int)part->sta);
  *efra = min_ii((int)(part->end + part->lifetime + 1.0f), max_ii(scene->r.pefra, scene->r.efra));
}

Because it takes a static value of the part->lifetime variable, but it's just a suspicion, I'm not sure.

I suspect the problem is in the file: > Particle_System.c In the line 1325: ``` void psys_get_pointcache_start_end(Scene *scene, ParticleSystem *psys, int *sfra, int *efra) { ParticleSettings *part = psys->part; *sfra = max_ii(1, (int)part->sta); *efra = min_ii((int)(part->end + part->lifetime + 1.0f), max_ii(scene->r.pefra, scene->r.efra)); } ``` Because it takes a static value of the part->lifetime variable, but it's just a suspicion, I'm not sure.

Germano Cavalcante commented

2020-09-10 23:42:30 +02:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2020-09-10 23:42:30 +02:00

I can confirm the problem.
I tested it in 2.79 and it used to work.
Here the file for 2.79:
particle_cache_bug_279.blend

I can confirm the problem. I tested it in 2.79 and it used to work. Here the file for 2.79: [particle_cache_bug_279.blend](https://archive.blender.org/developer/F8863318/particle_cache_bug_279.blend)

Germano Cavalcante commented

2020-09-11 23:05:16 +02:00

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

ichlubna commented

2022-11-19 15:39:16 +01:00

Added subscriber: @ichlubna

ichlubna commented

2022-11-19 15:39:16 +01:00

Is there any progress? The lifetime of particles still can't be animated - tested in 3.5.0 Alpha. I tried to simply animate the particles lifetime. It works fine in the 3D viewport, even after baking, even when rendering still image anywhere in the timeline, but when I try to render animation, the lifetime doesn't change and is stuck at the value of the first frame of the animation.
If you open the attached file, bake and render as animation, you can see that it doesn't change while playing it in the viewport looks OK.
particles.blend

Is there any progress? The lifetime of particles still can't be animated - tested in 3.5.0 Alpha. I tried to simply animate the particles lifetime. It works fine in the 3D viewport, even after baking, even when rendering still image anywhere in the timeline, but when I try to render animation, the lifetime doesn't change and is stuck at the value of the first frame of the animation. If you open the attached file, bake and render as animation, you can see that it doesn't change while playing it in the viewport looks OK. [particles.blend](https://archive.blender.org/developer/F13946021/particles.blend)

Philipp Oeser removed the

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Particles cache ignores animated lifetime #80592