Fusion360 to Blender .OBJ Dimensioning is off by 100x #114820

New Issue

Peter-87 · 2023-11-14T00:17:34+01:00

Peter-87 commented

2023-11-14 00:17:34 +01:00

System Information
Operating system: Mac Sonoma
Graphics card: Radeon 5300M

Blender Version
See attached files

Short description of error
In Fusion 360, when Exporting in .OBJ, and Importing to Blender , the Dimensions are wrong by a factor of 100x.
For example, Exporting a Fusion360 10mm .OBJ, will Import into Blender as a 1000mm .OBJ.

Fusions360 Dimensions have been set to Metric/mm.
Blenders Scene has been set to Metric/mm.
Both programs were restarted prior to Export/Import (Which is another glitch unto itself)

I am unsure of which program is at fault. Please investigate.

Exact steps for others to reproduce the error
See Description

**System Information** Operating system: Mac Sonoma Graphics card: Radeon 5300M **Blender Version** See attached files **Short description of error** In Fusion 360, when Exporting in .OBJ, and Importing to Blender , the Dimensions are wrong by a factor of 100x. For example, Exporting a Fusion360 10mm .OBJ, will Import into Blender as a 1000mm .OBJ. Fusions360 Dimensions have been set to Metric/mm. Blenders Scene has been set to Metric/mm. Both programs were restarted prior to Export/Import (Which is another glitch unto itself) I am unsure of which program is at fault. Please investigate. **Exact steps for others to reproduce the error** See Description

system-info.txt

6.3 KiB

MacBook Pro.spx

6.3 MiB

Peter-87 added the

labels 2023-11-14 00:17:34 +01:00

Germano Cavalcante commented

2023-11-14 04:30:45 +01:00

Thank you for bringing this to our attention, @Peter-87.

This issue sounds like a bug regarding dimensional scaling discrepancies when importing .OBJ files from Fusion 360 to Blender.

But to address this issue we would need the following additional information:

The version number of Blender you're using. You mentioned that it can be seen in the attached files, but they are not accessible via our current tools. Can you provide the Blender version directly?
The exact settings used when exporting the .OBJ file from Fusion 360 and when importing it into Blender.
A confirmation if this issue occurs with every .OBJ file exported from Fusion 360 or only specific files.
If possible, an example .OBJ file that exhibits this problem when imported into Blender. This would help in reproducing the issue.

Please ensure that all personal information or sensitive data is removed from the files before uploading them for privacy and security reasons.

Once we have this additional information, we can better assist you by escalating the problem to the developers who can further investigate the issue. Meanwhile, you might want to consider checking if there's a scaling option during the import/export process that has been overlooked which might be causing this issue. Blender and other 3D applications occasionally have different default scale settings that must be manually adjusted to match.

Thank you for bringing this to our attention, @Peter-87. This issue sounds like a bug regarding dimensional scaling discrepancies when importing .OBJ files from Fusion 360 to Blender. But to address this issue we would need the following additional information: 1. The version number of Blender you're using. You mentioned that it can be seen in the attached files, but they are not accessible via our current tools. Can you provide the Blender version directly? 2. The exact settings used when exporting the .OBJ file from Fusion 360 and when importing it into Blender. 3. A confirmation if this issue occurs with every .OBJ file exported from Fusion 360 or only specific files. 4. If possible, an example .OBJ file that exhibits this problem when imported into Blender. This would help in reproducing the issue. Please ensure that all personal information or sensitive data is removed from the files before uploading them for privacy and security reasons. Once we have this additional information, we can better assist you by escalating the problem to the developers who can further investigate the issue. Meanwhile, you might want to consider checking if there's a scaling option during the import/export process that has been overlooked which might be causing this issue. Blender and other 3D applications occasionally have different default scale settings that must be manually adjusted to match.

Germano Cavalcante added

Status

Needs Information from User

and removed

Status

Needs Triage

labels 2023-11-14 04:30:55 +01:00

Pratik Borhade commented

2023-11-14 04:43:03 +01:00

Hi, thanks for the report. This is due to the different default unit systems of software.
As far as I understand, obj format do not store the unit information (i.e. cm, mm): OBJ coordinates have no units, but OBJ files can contain scale information in a human readable comment line.
So when you export an object with 20mm size, .obj will store it as 20 units. While blender uses meter as default unit so object will appear 20m in size.
We've got similar report before, Aras explained it there with a nice example: #103473
Not a bug, closing.

Hi, thanks for the report. This is due to the different default unit systems of software. As far as I understand, obj format do not store the unit information (i.e. cm, mm): [OBJ coordinates have no units, but OBJ files can contain scale information in a human readable comment line. ](https://en.wikipedia.org/wiki/Wavefront_.obj_file#:~:text=OBJ%20coordinates%20have%20no%20units%2C%20but%20OBJ%20files%20can%20contain%20scale%20information%20in%20a%20human%20readable%20comment%20line.) So when you export an object with 20mm size, .obj will store it as 20 units. While blender uses meter as default unit so object will appear 20m in size. We've got similar report before, Aras explained it there with a nice example: #103473 Not a bug, closing.

Pratik Borhade closed this issue

2023-11-14 04:43:06 +01:00

Blender Bot added

Status

Archived

and removed

Status

Needs Information from User

labels 2023-11-14 04:43:08 +01:00

Pratik Borhade commented

2023-11-14 04:44:04 +01:00

@mano-wii , missed your comment. Had this page open for past few minutes. Feel free to reopen 🙂