Garbage materials with no users are saved. #49568

New Issue

Vyacheslav Kobozev · 2016-10-04T17:17:05+02:00

2016-10-04 17:17:05 +02:00

System Information
win7 x64

Blender Version
2.78

Short description of error
I found, that materials without users was saved. After resaving, they gone from main file, but still in the backup.

Garbage.7z

**System Information** win7 x64 **Blender Version** 2.78 **Short description of error** I found, that materials without users was saved. After resaving, they gone from main file, but still in the backup. [Garbage.7z](https://archive.blender.org/developer/F373809/Garbage.7z)

Vyacheslav Kobozev commented

2016-10-04 17:17:05 +02:00

Changed status to: 'Open'

Vyacheslav Kobozev commented

2016-10-04 17:17:05 +02:00

Added subscriber: @Vyach

Bastien Montagne commented

2016-10-05 08:06:03 +02:00

Added subscriber: @mont29

Bastien Montagne commented

2016-10-05 08:06:03 +02:00

Though this should not happen with new data-blocks handling code, this is how things have been working in Blender since ever…

Unless you can provide us a clear and detailed way to reproduce getting those materials with bad user count, we can’t do anything.

Though this should not happen with new data-blocks handling code, this is how things have been working in Blender since ever… Unless you can provide us a clear and detailed way to reproduce getting those materials with bad user count, we can’t do anything.

Vyacheslav Kobozev commented

2016-10-09 20:17:11 +02:00

I found how to reproduce this

for the initial i have file with few lights and one basic material (duffuse+glossy cycles shader), that assigned to fake user. And duplicating materials with Shift+D in my settings.
New file. Select and delete all. Add box. Add material slot to Object, assign those basic material to object, click to F to clear fake user
Now switch to Data and add material slot for data. And assign Basic material again, then make it unique and change color and name just to be sure.
Duplicate box few times. It will make few copies of both materials (assigned to data and to object).
Save file.
Select all, delete, save file, close Blender. Open Blender again, open this file again.
Add box and check what materials you can assign to it. I see all materials that was assigned to data, but all materials assigned to object was gone.

my initial file.7z
garbage2.7z — result

I found how to reproduce this 1. for the initial i have file with few lights and one basic material (duffuse+glossy cycles shader), that assigned to fake user. And duplicating materials with Shift+D in my settings. 2. New file. Select and delete all. Add box. Add material slot to Object, assign those basic material to object, click to F to clear fake user 3. Now switch to Data and add material slot for data. And assign Basic material again, then make it unique and change color and name just to be sure. 4. Duplicate box few times. It will make few copies of both materials (assigned to data and to object). 5. Save file. 6. Select all, delete, save file, close Blender. Open Blender again, open this file again. 7. Add box and check what materials you can assign to it. I see all materials that was assigned to data, but all materials assigned to object was gone. ![my dupl settings.jpg](https://archive.blender.org/developer/F376060/my_dupl_settings.jpg) [my initial file.7z](https://archive.blender.org/developer/F376062/my_initial_file.7z) [garbage2.7z](https://archive.blender.org/developer/F376063/garbage2.7z) — result

Bastien Montagne commented

2016-10-10 10:09:34 +02:00

Changed status from 'Open' to: 'Archived'

Bastien Montagne closed this issue

2016-10-10 10:09:34 +02:00

Bastien Montagne self-assigned this 2016-10-10 10:09:34 +02:00

Bastien Montagne commented

2016-10-10 10:09:35 +02:00

Ahhh… OK.

So there is no bug here in fact, what happens is that materials assigned to obdata (meshes etc.) 'belong' to those data, not to the object. When you delete the object, the meshes remain available, so their materials are still used by those meshes.

First save and reload will clear the meshes (since those had zero users), and next save and reload will clear the meshes' materials.

Ahhh… OK. So there is no bug here in fact, what happens is that materials assigned to obdata (meshes etc.) 'belong' to those data, not to the object. When you delete the object, the meshes remain available, so their materials are still used by those meshes. First save and reload will clear the meshes (since those had zero users), and next save and reload will clear the meshes' materials.

Vyacheslav Kobozev commented

2016-10-10 14:51:01 +02:00

Oh! I understand now how it works!
There is not hiererchical checking and deleting.

I think, it will be useful to have special clear button, that checks all unused data through the file and clear it immediately without 2 reloadings of file. I see why saving of data is made, it is useful to keep it from accidental loosing. But clearing will add balance to it. Just because sometimes you need to get rid of unwanted datas from lists (materials, meshes, textures) that appears after editing, testing and copying different versions.

Btw where I can suggest this to developers?

Oh! I understand now how it works! There is not hiererchical checking and deleting. I think, it will be useful to have special clear button, that checks all unused data through the file and clear it immediately without 2 reloadings of file. I see why saving of data is made, it is useful to keep it from accidental loosing. But clearing will add balance to it. Just because sometimes you need to get rid of unwanted datas from lists (materials, meshes, textures) that appears after editing, testing and copying different versions. Btw where I can suggest this to developers?

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Garbage materials with no users are saved. #49568