FBX import export - overscales camera focus distance by 1000 times #105088

New Issue

Andrej · 2023-12-27T06:40:28+01:00

Andrej commented

2023-12-27 06:40:28 +01:00

Blender 4.0.2

Way to reproduce it:

In default blender scene leave only camera and set it's focus distance to 15m or download attached file - camera_export.blend
Export it with default settings with Blender FBX or use camera_blender_original.fbx
Import it to Houdini or Maya (in my case it's Houdini)
Focus distance end up being 1 500 000 units (translation is 0,0,1798.66, which is similar to what it was in Blender).

Houdini:

Maya:

@Mysteryem @mont29

Blender 4.0.2 Way to reproduce it: 1) In default blender scene leave only camera and set it's focus distance to 15m or download attached file - [camera_export.blend](/attachments/056b73b3-9adc-4ee4-823e-d77b24b86720) 2) Export it with default settings with Blender FBX or use [camera_blender_original.fbx](/attachments/283a0d39-ef4c-49d2-8e72-6ed0ea1b9651) 3) Import it to Houdini or Maya (in my case it's Houdini) 4) Focus distance end up being 1 500 000 units (translation is 0,0,1798.66, which is similar to what it was in Blender). Houdini: ![image](/attachments/db08700c-70a3-41ee-a3dc-a1fbddf8346a) ![image](/attachments/4326fee1-6b38-433e-863e-06f8a10c2b33) Maya: ![image](/attachments/820e8f99-04bf-4dba-9d2e-27eac349f649) ![image](/attachments/7c320983-bbed-4743-98ed-4459759d163f) @Mysteryem @mont29

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Andrej added the

labels 2023-12-27 06:40:29 +01:00

Andrej changed title from ~~FBX import export - overscales camera focus distance by 100~~ to FBX import export - overscales camera focus distance by 1000 times

2023-12-27 06:48:46 +01:00

Thomas Barlow commented

2023-12-27 16:18:47 +01:00

The deprecated SetSpecificDistance() and GetSpecificDistance() in the FBX 2010 SDK (FBX 6.1) documentation said the values to get and set would be in millimetres, as per the discussion in https://developer.blender.org/D6666, but I suspect that only applied to those deprecated functions and not FocusDistance.Get() and FocusDistance.Set() which seem to have been the replacement for the deprecated functions.

The deprecated millimetre functions don't exist in the FBX 2011 SDK (FBX 7.1) and newer documentation.

The deprecated `SetSpecificDistance()` and `GetSpecificDistance()` in the FBX 2010 SDK (FBX 6.1) documentation said the values to get and set would be in millimetres, as per the discussion in https://developer.blender.org/D6666, but I suspect that only applied to those deprecated functions and not `FocusDistance.Get()` and `FocusDistance.Set()` which seem to have been the replacement for the deprecated functions. The deprecated millimetre functions don't exist in the FBX 2011 SDK (FBX 7.1) and newer documentation.

Andrej commented

2023-12-27 16:24:57 +01:00

The deprecated millimetre functions don't exist in the FBX 2011 SDK (FBX 7.1) and newer documentation.

Does it mean that it's safe to remove millimeter conversion now?

> The deprecated millimetre functions don't exist in the FBX 2011 SDK (FBX 7.1) and newer documentation. Does it mean that it's safe to remove millimeter conversion now?

Thomas Barlow commented

2023-12-27 18:02:50 +01:00

The deprecated millimetre functions don't exist in the FBX 2011 SDK (FBX 7.1) and newer documentation.

Does it mean that it's safe to remove millimeter conversion now?

I think the millimetre conversion was probably always wrong.

I would guess that some time in the past (pre FBX 6.1), getting or setting FocusDistance with the FBX SDK was only done with SetSpecificDistance() and GetSpecificDistance() which use/return millimetres, and that, at some point, the FBX SDK added the FocusDistance property (presumably in metres), which can be accessed directly, and kept the old functions around for a while for compatibility.

> > The deprecated millimetre functions don't exist in the FBX 2011 SDK (FBX 7.1) and newer documentation. > > Does it mean that it's safe to remove millimeter conversion now? I think the millimetre conversion was probably always wrong. I would guess that some time in the past (pre FBX 6.1), getting or setting FocusDistance with the FBX SDK was only done with `SetSpecificDistance()` and `GetSpecificDistance()` which use/return millimetres, and that, at some point, the FBX SDK added the `FocusDistance` property (presumably in metres), which can be accessed directly, and kept the old functions around for a while for compatibility.

Thomas Barlow referenced a pull request that will close this issue

2024-01-15 03:24:08 +01:00

Fix #105088: FBX Camera Focus Distance is interpreted as millimeters #105124

Thomas Barlow referenced this issue from a commit

2024-01-16 21:48:23 +01:00

Fix #105088: FBX Camera Focus Distance is interpreted as millimeters

Thomas Barlow closed this issue

2024-01-16 21:48:23 +01:00

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