Linking in a group with hair particles and force field doesn't affect the hair particles. #36300

New Issue

Reynante Martinez · 2013-07-27T04:25:53+02:00

Reynante Martinez commented

2013-07-27 04:25:53 +02:00

%%%--- Operating System, Graphics card ---

OS: Windows 8
Graphics card: Inter HD Graphics 4000

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

Blender version used: 2.68.0 revision 58386 and 2.68.1 revision 58611 (from builder.blender.org)
Blender version it worked on: none

- Short description of error ---

Linking a group with hair particles and force field doesn't affect the linked object which contains the particle system.
However, appending that group affects the particle system.

I have this current directory hierarchy as follows:

hair_with_forcefield/
hair_with_forcefield/blends
hair_with_forcefield/blends/scene
hair_with_forcefield/blends/props

/props contains the 'carpet.blend' file which has a plane with hair particles on it (both in a group called 'carpet'), affected by a single Force Field.

/scene contains the 'scene.blend' file where the 'carpet' group from 'carpet.blend' will be linked/appended into.

When doing a 'link' of the carpet group into the scene file, the hair particles doesn't seem to be affected by the force at all, given the force field is part of the linked group.

However, doing an 'append' of the carpet group into the scene file, the hair particles are affected by the force field. But already is a local group within the scene file and not a referenced/linked group.

Often, it is best to 'link' Groups/Objects for better organization, UI response, and doing appending often defeats this purpose.

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

Create the directory structures mentioned above.
Create a file named 'carpet.blend' and save it in /props.
With the 'carpet.blend' file active, create a simple plane, add a hair particle system, then add a force field to affect the hair particles, and increase the force field's strength.
Select the plane with the particle system and the force field, press CTRL G to create a group and name the group 'carpet'.
Create another Blender file named 'scene.blend' and save it in /scene.
Link the 'carpet' group from '/props/carpet.blend' by pressing CTRL ALT O (or going to File > Link), then browse for the carpet.blend file, then under Groups, select 'carpet'
It is now noticeable that the appearance of the particle system is not similar to that of the expected appearance from the original 'carpet.blend' file.
On step #6 though, if, instead of linking, we did an append, it will work fine.

Reyn%%%

%%%--- Operating System, Graphics card --- OS: Windows 8 Graphics card: Inter HD Graphics 4000 - Blender version with error, and version that worked --- Blender version used: 2.68.0 revision 58386 and 2.68.1 revision 58611 (from builder.blender.org) Blender version it worked on: none - Short description of error --- Linking a group with hair particles and force field doesn't affect the linked object which contains the particle system. However, appending that group affects the particle system. I have this current directory hierarchy as follows: - hair_with_forcefield/ - hair_with_forcefield/blends - hair_with_forcefield/blends/scene - hair_with_forcefield/blends/props /props contains the 'carpet.blend' file which has a plane with hair particles on it (both in a group called 'carpet'), affected by a single Force Field. /scene contains the 'scene.blend' file where the 'carpet' group from 'carpet.blend' will be linked/appended into. When doing a 'link' of the carpet group into the scene file, the hair particles doesn't seem to be affected by the force at all, given the force field is part of the linked group. However, doing an 'append' of the carpet group into the scene file, the hair particles are affected by the force field. But already is a local group within the scene file and not a referenced/linked group. Often, it is best to 'link' Groups/Objects for better organization, UI response, and doing appending often defeats this purpose. - Steps for others to reproduce the error (preferably based on attached .blend file) --- 1. Create the directory structures mentioned above. 2. Create a file named 'carpet.blend' and save it in /props. 3. With the 'carpet.blend' file active, create a simple plane, add a hair particle system, then add a force field to affect the hair particles, and increase the force field's strength. 4. Select the plane with the particle system and the force field, press CTRL G to create a group and name the group 'carpet'. 5. Create another Blender file named 'scene.blend' and save it in /scene. 6. Link the 'carpet' group from '/props/carpet.blend' by pressing CTRL ALT O (or going to File > Link), then browse for the carpet.blend file, then under Groups, select 'carpet' 7. It is now noticeable that the appearance of the particle system is not similar to that of the expected appearance from the original 'carpet.blend' file. 8. On step #6 though, if, instead of linking, we did an append, it will work fine. - Reyn%%%

Reynante Martinez commented

2013-07-27 04:25:53 +02:00

Changed status to: 'Open'

Lukas Tönne commented

2013-07-29 10:36:07 +02:00

%%%This is sort-of a duplicate of #35264 (the cause is the same): Force fields do not work in group instances. When linking the group with carpet mesh/particles + force field it also loads the individual objects of the group (they are in bpy.data), but they don't get linked into the scene themselves (linking is an ambiguous term here, the first usage meaning a copy of the data from another file, the latter meaning a "object base" in the scene that actually places an object in that scene).

Linking (not necessarily appending) the "Field" object explicitly into the scene file solves the issue, although it's not an optimal solution. It may be possible to solve the problem in a general way by allowing force field in group instances, but i cannot promise anything yet. Will have to see if it can be done cleanly without major hacks.%%%

%%%This is sort-of a duplicate of #35264 (the cause is the same): Force fields do not work in group instances. When linking the group with carpet mesh/particles + force field it also loads the individual objects of the group (they are in bpy.data), but they don't get linked into the scene themselves (linking is an ambiguous term here, the first usage meaning a copy of the data from another file, the latter meaning a "object base" in the scene that actually places an object in that scene). Linking (not necessarily appending) the "Field" object explicitly into the scene file solves the issue, although it's not an optimal solution. It may be possible to solve the problem in a general way by allowing force field in group instances, but i cannot promise anything yet. Will have to see if it can be done cleanly without major hacks.%%%

Reynante Martinez commented

2013-07-29 12:40:22 +02:00

%%%Thanks so much, Lukas.

Reyn%%%

%%%Thanks so much, Lukas. - Reyn%%%

Lukas Tönne commented

2013-09-24 16:03:45 +02:00

%%%Closing this as a ToDo
http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/Tools#Collisions

It not really possible to fix with the way effectors (force fields and colliders) are used atm. Duplis are also primarily a visual feature, although i agree it would be helpful to support this at least in group instances.%%%

%%%Closing this as a ToDo http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/Tools#Collisions It not really possible to fix with the way effectors (force fields and colliders) are used atm. Duplis are also primarily a visual feature, although i agree it would be helpful to support this at least in group instances.%%%

Lukas Tönne commented

2013-09-24 16:03:45 +02:00

Changed status from 'Open' to: 'Archived'

Lukas Tönne closed this issue

2013-09-24 16:03:45 +02:00

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Linking in a group with hair particles and force field doesn't affect the hair particles. #36300