Object material turns to Grease Pencil materials - Bug #71533

New Issue

Aleksandr · 2019-11-13T08:37:23+01:00

Aleksandr commented

2019-11-13 08:37:23 +01:00

System Information
Operating system: Linux-4.15.0-66-generic-x86_64-with-debian-buster-sid 64 Bits
Graphics card: GeForce GTX 1050 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 435.21

Blender Version
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-08 22:59, hash: 0a0d735acd
Worked: (optional)

Short description of error
Material of mesh object turns to Grease Pencil material.

Exact steps for others to reproduce the error
I just created object and plug it to use in hair particle system and it's material turns to Grease Pencil material so I can not to change material properly anymore. It happens time to time.

Bug_Material.blend

**System Information** Operating system: Linux-4.15.0-66-generic-x86_64-with-debian-buster-sid 64 Bits Graphics card: GeForce GTX 1050 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 435.21 **Blender Version** Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-08 22:59, hash: `0a0d735acd` Worked: (optional) **Short description of error** Material of mesh object turns to Grease Pencil material. **Exact steps for others to reproduce the error** I just created object and plug it to use in hair particle system and it's material turns to Grease Pencil material so I can not to change material properly anymore. It happens time to time. ![1.png](https://archive.blender.org/developer/F8057211/1.png) [Bug_Material.blend](https://archive.blender.org/developer/F8057199/Bug_Material.blend)

Aleksandr commented

2019-11-13 08:37:23 +01:00

Added subscriber: @viadvena

Aleksandr commented

2019-11-13 09:10:15 +01:00

Blender convert mesh to Grease Pencil object. When I exit from material tab, duplicate this object and convert it to mesh - command works, but after this I go to material tab and mesh turns to grease pencil back and produce error when I try to convert it to mesh. I delete material and conversion works and object turns to a mesh but material lost forever.

![2.png](https://archive.blender.org/developer/F8057360/2.png) **Blender convert mesh to Grease Pencil object**. When I exit from material tab, duplicate this object and convert it to mesh - command works, but after this I go to material tab and mesh turns to grease pencil back and produce error when I try to convert it to mesh. I delete material and conversion works and object turns to a mesh but material lost forever.

Philipp Oeser commented

2019-11-13 10:03:27 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2019-11-13 10:03:27 +01:00

Having a hard time reproducing this:

could you try to come up with the steps from the default scene to reproduce this?
or do you have a file we can open and then do a couple of steps that lead to the problem?

I just created object and plug it to use in hair particle system and it's material turns to Grease Pencil material

cannot reproduce

Having a hard time reproducing this: - could you try to come up with the steps from the default scene to reproduce this? - or do you have a file we can open and then do a couple of steps that lead to the problem? > I just created object and plug it to use in hair particle system and it's material turns to Grease Pencil material cannot reproduce

Philipp Oeser commented

2019-11-13 10:04:34 +01:00

And yes, I can see the problem in the file from the report (it is just that I cannot reproduce it from scratch or with the steps provided)

Aleksandr commented

2019-11-13 10:12:04 +01:00

I picked blendfile before with corrupted object. Here I pick actual scene where all started.
test_MatBug.blend
Please look deeply in collections with suffix _S - it's origin meshes for instances in particle systems. As I see all meshes that was instanced turns their mats in gp mats.

I picked blendfile before with corrupted object. Here I pick actual scene where all started. [test_MatBug.blend](https://archive.blender.org/developer/F8057867/test_MatBug.blend) Please look deeply in collections with suffix _S - it's origin meshes for instances in particle systems. As I see all meshes that was instanced turns their mats in gp mats.

Aleksandr commented

2019-11-13 10:16:41 +01:00

Also I can assume that it's happens only with procedural materials without image textures. And used Annotation tool with draw mode above meshes. It's just happens and unfortunately I can not say more. At some moment I just noticed it.

Antonio Vazquez commented

2019-11-13 10:27:34 +01:00

Added subscriber: @antoniov

Antonio Vazquez commented

2019-11-13 10:27:34 +01:00

@lichtwerk I'm looking a t the bug too. Try to find where BKE_material_init_gpencil_settings() is called. If we found why this is called, we will catch the bug.

@lichtwerk I'm looking a t the bug too. Try to find where `BKE_material_init_gpencil_settings()` is called. If we found why this is called, we will catch the bug.

Antonio Vazquez commented

2019-11-13 10:34:37 +01:00

@viadvena While we found the solution to the bug, you can recover your material running these lines in console:

bpy.data.materials.remove_gpencil_data(ma)```

@viadvena While we found the solution to the bug, you can recover your material running these lines in console: ```ma = bpy.context.active_object.material_slots- [x].material bpy.data.materials.remove_gpencil_data(ma)```

Aleksandr commented

2019-11-13 10:40:09 +01:00

In #71533#810151, @antoniov wrote:
@viadvena While we found the solution to the bug, you can recover your material running these lines in console:
bpy.data.materials.remove_gpencil_data(ma)```

Thank you! I appreciate this!

> In #71533#810151, @antoniov wrote: > @viadvena While we found the solution to the bug, you can recover your material running these lines in console: > > ```ma = bpy.context.active_object.material_slots- [x].material > bpy.data.materials.remove_gpencil_data(ma)``` Thank you! I appreciate this!

Antonio Vazquez commented

2019-11-13 10:41:11 +01:00

I'm going to create an script to fix your file in one step.

Antonio Vazquez commented

2019-11-13 10:44:31 +01:00

This script fix the file:


for ob in bpy.data.objects:

if ob.type == 'MESH':
for slot in ob.material_slots:
bpy.data.materials.remove_gpencil_data(slot.material)```

This script fix the file: ```import bpy for ob in bpy.data.objects: ``` if ob.type == 'MESH': for slot in ob.material_slots: bpy.data.materials.remove_gpencil_data(slot.material)```

Aleksandr commented

2019-11-13 10:57:18 +01:00

In #71533#810159, @antoniov wrote:
This script fix the file:


for ob in bpy.data.objects:
    if ob.type == 'MESH':
        for slot in ob.material_slots:
            bpy.data.materials.remove_gpencil_data(slot.material)```

Thanks a lot! It works) Could you please to help me with another thing: how can I force recompile shaders? Sometimes materials completely won't to updates. I struggled with this few times and in this situations helps install new build of blender. But may be there is much more esthetic way.

> In #71533#810159, @antoniov wrote: > This script fix the file: > > ```import bpy > > for ob in bpy.data.objects: > if ob.type == 'MESH': > for slot in ob.material_slots: > bpy.data.materials.remove_gpencil_data(slot.material)``` Thanks a lot! It works) Could you please to help me with another thing: how can I force recompile shaders? Sometimes materials completely won't to updates. I struggled with this few times and in this situations helps install new build of blender. But may be there is much more esthetic way. ![1.png](https://archive.blender.org/developer/F8058216/1.png)

Philipp Oeser commented

2019-11-13 11:10:18 +01:00

@antoniov: great!

Think we confirm this then? (or do we wnat to merge with #63707?)

@antoniov: great! Think we confirm this then? (or do we wnat to merge with #63707?)

Antonio Vazquez commented

2019-11-13 11:14:56 +01:00

We could merge both, but I'm unable to reproduce it, so no idea how fix it.

Philipp Oeser commented

2019-11-13 11:59:10 +01:00

In #71533#810175, @antoniov wrote:
We could merge both, but I'm unable to reproduce it, so no idea how fix it.

Ah, I was thinking you were squashing the bug already.

While we found the solution to the bug

Anyways, since both issues seems to stem from the same roots [Annotations in play...], will merge these reports.
@viadvena : lets continue discussion in #63707, and please keep us up to date if you have found a way to reproduce [thanx for providing test_MatBug.blend -- but the corruption has already taken place in that file as well, and I am still not able to reproduce... will try more though...]

> In #71533#810175, @antoniov wrote: > We could merge both, but I'm unable to reproduce it, so no idea how fix it. Ah, I was thinking you were squashing the bug already. > While we found the solution to the bug Anyways, since both issues seems to stem from the same roots [Annotations in play...], will merge these reports. @viadvena : lets continue discussion in #63707, and please keep us up to date if you have found a way to reproduce [thanx for providing `test_MatBug.blend` -- but the corruption has already taken place in that file as well, and I am still not able to reproduce... will try more though...]

Philipp Oeser commented

2019-11-13 11:59:20 +01:00

Closed as duplicate of #63707

Philipp Oeser closed this issue

2019-11-13 11:59:20 +01:00

Yianni Papazis commented

2019-12-15 05:54:18 +01:00

Added subscriber: @Yianni

Yianni Papazis commented

2019-12-15 05:54:18 +01:00

This comment was removed by @Yianni

*This comment was removed by @Yianni*

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Object material turns to Grease Pencil materials - Bug #71533