[NewTek MDD] Import error #104700

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BorisG · 2023-06-17T20:14:56+02:00

BorisG commented

2023-06-17 20:14:56 +02:00

Hello everyone,

First of all, I hope I'm raising this issue in the appropriate place.
Second of all, thank you for your work 🙏

I'm a complete Blender beginner, so my vocabulary might not be very accurate. Also, this issue might even be a misunderstanding on my end. If it's the case, sorry for that.

System Information
Operating system: macOS 13.4 (22F66)
Graphics card: Apple M1 Pro (=> the culprit? 🤔)

Blender Version
Broken: 3.5.1

Short description of error
struct.error: unpack requires a buffer of 12 bytes
This error happens right when importing the previously saved .mdd file (see steps below).

Exact steps for others to reproduce the error

Follow this short tutorial (or use attached files below).
When reaching the step requiring the .mdd file import, the error is displayed, and the plane is broken.

Here is the .mdd file the tutorial makes us create.
Here is the .blend file with all the steps from the tutorial up until the .mdd import step.
Below is the error log:

Thanks in advance for your help ! 😊

Hello everyone, First of all, I hope I'm raising this issue in the appropriate place. Second of all, thank you for your work 🙏 I'm a complete Blender beginner, so my vocabulary might not be very accurate. Also, this issue might even be a misunderstanding on my end. If it's the case, sorry for that. **System Information** Operating system: macOS 13.4 (22F66) Graphics card: Apple M1 Pro (=> the culprit? 🤔) **Blender Version** Broken: 3.5.1 **Short description of error** `struct.error: unpack requires a buffer of 12 bytes` This error happens right when importing the previously saved `.mdd` file (see steps below). **Exact steps for others to reproduce the error** * Follow [this](https://www.youtube.com/watch?v=npFqqy-tTYw) short tutorial (or use attached files below). * When reaching the step requiring the `.mdd` file import, the error is displayed, and the plane is broken. [Here](/attachments/91956518-a681-4baf-97dd-13438e4c3c38) is the `.mdd` file the tutorial makes us create. [Here](/attachments/aa2e379a-d4b5-47c4-803c-29cd68ed9883) is the `.blend` file with all the steps from the tutorial up until the `.mdd` import step. Below is the error log: ![Screenshot 2023-06-17 at 20.05.33.png](/attachments/7af190e0-17d8-43c4-afaf-92eaa9e29c4b) Thanks in advance for your help ! 😊

tuto-SK-MDD.blend

2.0 MiB

wave-animation.mdd

7.2 MiB

Screenshot 2023-06-17 at 20.05.33.png

324 KiB

BorisG added the

labels 2023-06-17 20:14:56 +02:00

Pratik Borhade commented

2023-06-19 08:31:37 +02:00

Hi, add-on io_shape_mmd mentioned in the python-traceback is not part of the official add-on repository of blender.
Please report the issue to add-on developers

Hi, add-on `io_shape_mmd` mentioned in the python-traceback is not part of the official add-on repository of blender. Please report the issue to add-on developers

Pratik Borhade closed this issue

2023-06-19 08:31:38 +02:00

Blender Bot added

and removed

labels 2023-06-19 08:31:39 +02:00

Ryan Inch commented

2023-06-19 10:27:35 +02:00

@PratikPB2123 I'm pretty sure it is, the support level is even indicated as 'OFFICIAL'. https://projects.blender.org/blender/blender-addons/src/branch/main/io_shape_mdd

Ryan Inch reopened this issue

2023-06-19 10:27:36 +02:00

Blender Bot added

and removed

labels 2023-06-19 10:27:37 +02:00

Pratik Borhade commented

2023-06-19 10:59:00 +02:00

Thanks @Imaginer .

Somehow slipped through my eyes. Sorry for that.

Thanks @Imaginer . Somehow slipped through my eyes. Sorry for that.

Ryan Inch commented

2023-06-20 08:26:48 +02:00

@PratikPB2123 You're welcome and no worries.

BorisG commented

2023-06-21 18:11:40 +02:00

Thank you guys for your first look at this 🙏

Just so you know, I sent an email to the author earlier this day (found it here).

Thank you guys for your first look at this 🙏 Just so you know, I sent an email to the author earlier this day (found it [here](https://projects.blender.org/blender/blender-addons/src/branch/main/io_shape_mdd/import_mdd.py#L15)).

BorisG commented

2023-07-04 18:13:10 +02:00

Hello,

After some investigations, I found that when I imported the .mdd, it had less verts than required, thus unpacking nothing, and causing the error. My hypothesis was that some problem occurred during the export, making the .mdd file shorter than it should have been.

Before diving deeper, I decided to try upgrading to blender 3.6... and it worked.
It seemed weird to me that upgrading was a solution, so I downgraded back to 3.5.1, just to make sure... and it worked as well.

Two possibilities:

I had some problem with blender or the mdd i/o extension, and reinstalling fixed it.
I made a mistake when applying the tutorial steps. As an example, exporting an .mdd from the Cube object instead of Plane causes the error (names are from the attached .blend file in the original post) when importing it on the Plane.001 object.

My guess is that it is option 2. Sorry for that.

I think adding an error message to explain that this error happens because the number of verts in the .mdd file doesn't match the object's number of verts it is applied to could be useful, and save some debugging time to others.

Have a nice day/evening,

Boris

Hello, After some investigations, I found that when I imported the `.mdd`, it had less [verts](https://projects.blender.org/blender/blender-addons/src/branch/main/io_shape_mdd/import_mdd.py#L43) than required, thus [unpacking](https://projects.blender.org/blender/blender-addons/src/branch/main/io_shape_mdd/import_mdd.py#L44) nothing, and causing the error. My hypothesis was that some problem occurred during the export, making the `.mdd` file shorter than it should have been. Before diving deeper, I decided to try upgrading to blender 3.6... and it worked. It seemed weird to me that upgrading was a solution, so I downgraded back to 3.5.1, just to make sure... and it worked as well. Two possibilities: 1. I had some problem with blender or the mdd i/o extension, and reinstalling fixed it. 2. I made a mistake when applying the tutorial steps. As an example, exporting an `.mdd` from the `Cube` object instead of `Plane` causes the error (names are from the attached `.blend` file in the original post) when importing it on the `Plane.001` object. My guess is that it is option 2. Sorry for that. I think adding an error message to explain that this error happens because the number of verts in the `.mdd` file doesn't match the object's number of verts it is applied to could be useful, and save some debugging time to others. Have a nice day/evening, Boris

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