Poor randomness in particle emission with a grid of resolution 32 (and 16) #35598

New Issue

Yu Asakusa · 2013-06-01T23:48:13+02:00

Yu Asakusa commented

2013-06-01 23:48:13 +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 2.67b 64-bit (official binary)
Blender r57165 64-bit (http://builder.blender.org/download/blender-2.67-r57165-win64.zip)
Working: none I know of
- Short description of error ---
  When a particle system is set up in a particular way (see below), supposedly random variation in the particle emission locations becomes very regular.
- Steps for others to reproduce the error (preferably based on attached .blend file) ---

Open the attached blend file, or do the following:
1a. Load factory settings.
1b. Remove the default cube.
1c. Add a plane, switch to the top view, and zoom the view to the added plane.
1d. Add a particle system.
1e. Change the particle settings as follows: in the Emission panel, change End to 1, choose Grid as distribution, change Resolution to 32, and change Random (the one next to Resolution) to 1.
1f. Optionally, in the Physics panel, change the physics type to No.
Observe that particles make straight lines parallel to the X-axis.

Notes:

Changing the seed for the particle system does not solve the issue, although different seeds give different particle locations.
In step 1e, changing the emission end frame to 1 is not essential, but gives a better visualization of the issue.
A similar issue exists also when Resolution is 16 instead of 32, although it is less apparent. Curiously the issue does not seem to show up with any other values of Resolution.
%%%

%%%--- 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 2.67b 64-bit (official binary) * Blender r57165 64-bit (http://builder.blender.org/download/blender-2.67-r57165-win64.zip) Working: none I know of - Short description of error --- When a particle system is set up in a particular way (see below), supposedly random variation in the particle emission locations becomes very regular. - Steps for others to reproduce the error (preferably based on attached .blend file) --- 1. Open the attached blend file, or do the following: 1a. Load factory settings. 1b. Remove the default cube. 1c. Add a plane, switch to the top view, and zoom the view to the added plane. 1d. Add a particle system. 1e. Change the particle settings as follows: in the Emission panel, change End to 1, choose Grid as distribution, change Resolution to 32, and change Random (the one next to Resolution) to 1. 1f. Optionally, in the Physics panel, change the physics type to No. 2. Observe that particles make straight lines parallel to the X-axis. Notes: * Changing the seed for the particle system does not solve the issue, although different seeds give different particle locations. * In step 1e, changing the emission end frame to 1 is not essential, but gives a better visualization of the issue. * A similar issue exists also when Resolution is 16 instead of 32, although it is less apparent. Curiously the issue does not seem to show up with any other values of Resolution. %%%

Yu Asakusa commented

2013-06-01 23:48:13 +02:00

Changed status to: 'Open'

Ton Roosendaal commented

2013-06-06 17:52:19 +02:00

%%%Unfortunately our particle system has become an orphan, with no developer actively maintaining it. We will only handle crucial errors here now (like crashing).
All reports related to particles now get collected in our wiki for future reference.

Added it here.
http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/Tools#Particles

Thanks, sorry for not being able to help out.%%%

%%%Unfortunately our particle system has become an orphan, with no developer actively maintaining it. We will only handle crucial errors here now (like crashing). All reports related to particles now get collected in our wiki for future reference. Added it here. http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/Tools#Particles Thanks, sorry for not being able to help out.%%%

Ton Roosendaal commented

2013-06-06 17:52:19 +02:00

Changed status from 'Open' to: 'Archived'

Ton Roosendaal closed this issue

2013-06-06 17:52:19 +02:00

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Poor randomness in particle emission with a grid of resolution 32 (and 16) #35598