Disk caches of multiple particle systems on a single object sometimes overwrite each other #35328

New Issue

Yu Asakusa · 2013-05-12T17:43:15+02:00

Yu Asakusa commented

2013-05-12 17:43:15 +02:00

%%%--- Operating System, Graphics card ---
Windows 7 64-bit Service Pack 1, Mobile Intel 4 Series Express Chipset

- Blender version with error, and version that worked ---

Error: Blender 2.67 64-bit (official)
Working: none I know of

- Short description of error ---

If two particle systems are added to a single object and both use disk cache, they sometimes behave incorrectly, apparently because both particle systems use the same cache file name.

- Steps for others to reproduce the error (preferably based on attached .blend file) ---

Either open the attached .blend file or follow the following steps 1a–1h:
1a. Load the factory settings.
1b. Save .blend file to an empty directory.
1c. Add a particle system to the default Cube, and change its name to Downward.
1d. Change the settings of Downward as follows: in section Emission, change Start to 25; in section Cache, change Cache Step to 1 and check Disk Cache.
1e. Make a duplicate of Cube (Shift+D), named Cube.001 by default.
1f. Delete the original Cube.
1g. Add another particle system to Cube.001, and change its name to Upward.
1h. Change the settings of Upward as follows: in section Cache, change Cache Step to 1 and check Disk Cache; in Field Weights, change Gravity to -1. Note that the emission time of Upward is from frame 1 to frame 200 (the default settings).
Start animation. After frame 25, particle system Upward of Cube.001 stops working.
(optional) If you select Upward and start animation, you can see that the particles of Upward use the locations of the particles of Downward after frame 25.

Remarks:

A workaround is to give different cache file names to two particle systems. Note that if we use this workaround with the attached example, the point cache files for the two particle systems have the same suffix _00. If I am not mistaken, this means that both particle systems think that they are attached to the first Particle System modifier, which I believe should not happen.
%%%

%%%--- Operating System, Graphics card --- Windows 7 64-bit Service Pack 1, Mobile Intel 4 Series Express Chipset - Blender version with error, and version that worked --- Error: Blender 2.67 64-bit (official) Working: none I know of - Short description of error --- If two particle systems are added to a single object and both use disk cache, they sometimes behave incorrectly, apparently because both particle systems use the same cache file name. - Steps for others to reproduce the error (preferably based on attached .blend file) --- 1. Either open the attached .blend file or follow the following steps 1a–1h: 1a. Load the factory settings. 1b. Save .blend file to an empty directory. 1c. Add a particle system to the default Cube, and change its name to Downward. 1d. Change the settings of Downward as follows: in section Emission, change Start to 25; in section Cache, change Cache Step to 1 and check Disk Cache. 1e. Make a duplicate of Cube (Shift+D), named Cube.001 by default. 1f. Delete the original Cube. 1g. Add another particle system to Cube.001, and change its name to Upward. 1h. Change the settings of Upward as follows: in section Cache, change Cache Step to 1 and check Disk Cache; in Field Weights, change Gravity to -1. Note that the emission time of Upward is from frame 1 to frame 200 (the default settings). 2. Start animation. After frame 25, particle system Upward of Cube.001 stops working. 3. (optional) If you select Upward and start animation, you can see that the particles of Upward use the locations of the particles of Downward after frame 25. Remarks: A workaround is to give different cache file names to two particle systems. Note that if we use this workaround with the attached example, the point cache files for the two particle systems have the same suffix _00. If I am not mistaken, this means that both particle systems think that they are attached to the first Particle System modifier, which I believe should not happen. %%%

Yu Asakusa commented

2013-05-12 17:43:15 +02:00

Changed status to: 'Open'

Sergey Sharybin self-assigned this 2014-02-03 15:27:05 +01:00

Sergey Sharybin commented

2014-02-03 15:27:05 +01:00

Will try to look into this issue. Perhaps it's not so difficult :)