When importing two USDZ objects only the material of the first is preserved #114489

New Issue

Wouter Stomp · 2023-11-04T20:46:45+01:00

Wouter Stomp commented

2023-11-04 20:46:45 +01:00

System Information
Operating system: macOS-14.0-arm64-arm-64bit 64 Bits
Graphics card: Metal API Apple M1 Max 1.2

Blender Version
Broken: version: 4.1.0 Alpha, branch: main, commit date: 2023-11-03 17:00, hash: 9b0ea21a5bbc
Worked: unknown

Short description of error
When importing two USDZ objects only the material of the first is preserved. It seems like two materials are created ('make unique' is checked for the material in the importer), but image textures are not made unique/imported when a identically named image is already in the blend file.

Exact steps for others to reproduce the error
Import one of the two attached USDZ files, then the other. For the first one the material is shown correctly while the second gets the same material as the first object (see screenshot).

**System Information** Operating system: macOS-14.0-arm64-arm-64bit 64 Bits Graphics card: Metal API Apple M1 Max 1.2 **Blender Version** Broken: version: 4.1.0 Alpha, branch: main, commit date: 2023-11-03 17:00, hash: `9b0ea21a5bbc` Worked: unknown **Short description of error** When importing two USDZ objects only the material of the first is preserved. It seems like two materials are created ('make unique' is checked for the material in the importer), but image textures are not made unique/imported when a identically named image is already in the blend file. **Exact steps for others to reproduce the error** Import one of the two attached USDZ files, then the other. For the first one the material is shown correctly while the second gets the same material as the first object (see screenshot).

AR-Code-Object-Capture-app-1695668621.usdz

6.4 MiB

AR-Code-Object-Capture-app-1695666562.usdz

9.3 MiB

Schermafbeelding 2023-11-04 om 20.42.37.png

1.2 MiB

Wouter Stomp added the

labels 2023-11-04 20:46:46 +01:00

Philipp Oeser commented

2023-11-06 11:59:49 +01:00

I can confirm the behavior.

However, you can get around the problem following these steps:

import the first USD, using the texture as packed
unpack the texture
import the second USD, also using packed

Now the textures are individual in storage.
This however is also not ideal (since this workflow only works for two materials using equally named textures, as soon as a third USD comes in, the workflow also collapses).

Basically, handling name collisions is a bit weak (also see #100361 in regards to unpacking).

Actually, I would assume the recommended way of doing this would be the following (if you know in advance these textures are equally named):

import the first USD, using the texture as Copy
use a unique folder name in the option:
import the second USD, using the texture as Copy again
use a different unique folder name in the option:

Does this work for you?

I can confirm the behavior. However, you can get around the problem following these steps: - import the first USD, using the texture as `packed` - unpack the texture - import the second USD, also using `packed` Now the textures are individual in storage. This however is also not ideal (since this workflow only works for two materials using equally named textures, as soon as a third USD comes in, the workflow also collapses). Basically, handling name collisions is a bit weak (also see #100361 in regards to unpacking). Actually, I would assume the recommended way of doing this would be the following (if you know in advance these textures are equally named): - import the first USD, using the texture as `Copy` - use a unique folder name in the option: ![image](/attachments/bce8f24c-7c75-4b04-9fab-1e2cfb6a6ae1) - import the second USD, using the texture as `Copy` again - use a different unique folder name in the option: ![image](/attachments/9c0a4ee4-662c-4014-b822-8ff474df1fd5) Does this work for you?

image.png

10 KiB

image.png

10 KiB

Philipp Oeser added

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Needs Information from User

and removed

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Needs Triage

labels 2023-11-06 11:59:57 +01:00

Wouter Stomp commented

2023-11-06 12:29:15 +01:00

As a workaround that works yes. However I would expect the 'make unique' option to take care of this, the tooltip says "Import each USD material as a unique Blender material"; I would expect that to include the image textures used within the material as well.

Strangely if you want to keep them packed, renaming the image textures after the first import does not work as a workaround, the second imported item will still get the renamed image textures attached.

(if you know in advance these textures are equally named)

That is a big if; in my case I was simply importing objects scanned with a 3d scanning app, I would have no idea how it names its textures before running into this bug.

As a workaround that works yes. However I would expect the 'make unique' option to take care of this, the tooltip says "Import each USD material as a unique Blender material"; I would expect that to include the image textures used within the material as well. Strangely if you want to keep them packed, renaming the image textures after the first import does not work as a workaround, the second imported item will still get the renamed image textures attached. > (if you know in advance these textures are equally named) That is a big if; in my case I was simply importing objects scanned with a 3d scanning app, I would have no idea how it names its textures before running into this bug.

Philipp Oeser commented

2023-11-06 12:53:35 +01:00

Strangely if you want to keep them packed, renaming the image textures after the first import does not work as a workaround, the second imported item will still get the renamed image textures attached.

It is not the ID name you give to the texture, but the packed path that is relevant here (and these are still the same)

As a workaround that works yes. However I would expect the 'make unique' option to take care of this, the tooltip says "Import each USD material as a unique Blender material"; I would expect that to include the image textures used within the material as well.

That I would consider as a request for improved behavior (not a bug), the materials after all are unique (just not the textures).
There are also situations where you would actually want the same texture to be used (think of atlas textures).
If something would need to be changed here, we would probably need an additional option (something like Texture Name Collisions)

> Strangely if you want to keep them packed, renaming the image textures after the first import does not work as a workaround, the second imported item will still get the renamed image textures attached. It is not the ID name you give to the texture, but the packed path that is relevant here (and these are still the same) ![image](/attachments/c320d9c8-1581-4281-8f4a-0466650eb819) ![image](/attachments/ae93d39c-cb90-4b91-8ce3-0f1f25013889) > As a workaround that works yes. However I would expect the 'make unique' option to take care of this, the tooltip says "Import each USD material as a unique Blender material"; I would expect that to include the image textures used within the material as well. > That I would consider as a request for improved behavior (not a bug), the materials after all are unique (just not the textures). There are also situations where you would actually want the same texture to be used (think of atlas textures). If something would need to be changed here, we would probably need an additional option (something like `Texture Name Collisions`)

image.png

82 KiB

image.png

75 KiB

Wouter Stomp commented

2023-11-06 15:03:39 +01:00

Thanks for all the explanations. A texture name collision option would definitely be an improvement.

Philipp Oeser commented

2023-11-27 14:09:05 +01:00

Thanks for all the explanations. A texture name collision option would definitely be an improvement.

OK, see below on where to suggest improvements, will have to close this report though (due to not being a real bug)

Thanks for the report, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior. Closing as this bug tracker is only for bugs and errors.

For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests

For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug

> Thanks for all the explanations. A texture name collision option would definitely be an improvement. OK, see below on where to suggest improvements, will have to close this report though (due to not being a real bug) ``` Thanks for the report, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior. Closing as this bug tracker is only for bugs and errors. For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug ```

Philipp Oeser closed this issue

2023-11-27 14:09:07 +01:00

Blender Bot added

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Archived

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Needs Information from User

labels 2023-11-27 14:09:10 +01:00

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