Forum

Author Topic: FBX Export settings  (Read 6261 times)

maddin

  • Full Member
  • ***
  • Posts: 161
    • View Profile
FBX Export settings
« on: January 24, 2017, 05:11:56 PM »
When exporting a dataset as FBX, the resulting file seems to have some rather odd attributes and I wonder where these came from and whether there is a way to change those defaults:

1.) The FBX is saved as "y-Up", even though PhotoScan is "z-Up" (correct?). So when importing such files into 3ds Max, they come out as rotated by 90 degrees. This is not a big issue but rather annoying.

2.) The FBX file used "Centimeters" as units, even though every measurement in PhotoScan uses meters. I find that confusing.

While both of these settings a no big deal, especially when using FBX to go back and forth between PhotoScan and the 3D application, those scaling and rotation changes are potential sources of error.

Is there some way to influence the settings used by PhotoScan when exporting as FBX?

maddin

  • Full Member
  • ***
  • Posts: 161
    • View Profile
Re: FBX Export settings
« Reply #1 on: February 01, 2017, 10:00:50 PM »
When exporting a dataset as FBX, the resulting file seems to have some rather odd attributes and I wonder where these came from and whether there is a way to change those defaults:

1.) The FBX is saved as "y-Up", even though PhotoScan is "z-Up" (correct?). So when importing such files into 3ds Max, they come out as rotated by 90 degrees. This is not a big issue but rather annoying.

2.) The FBX file used "Centimeters" as units, even though every measurement in PhotoScan uses meters. I find that confusing.

While both of these settings a no big deal, especially when using FBX to go back and forth between PhotoScan and the 3D application, those scaling and rotation changes are potential sources of error.

Is there some way to influence the settings used by PhotoScan when exporting as FBX?

*bump*

Anyone?

maddin

  • Full Member
  • ***
  • Posts: 161
    • View Profile
Re: FBX Export settings
« Reply #2 on: February 07, 2017, 03:26:25 PM »
So, is this a bug I should report somewhere?

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 14965
    • View Profile
Re: FBX Export settings
« Reply #3 on: February 07, 2017, 05:02:29 PM »
Hello maddin,

Looks more like feature request for additional export settings.
Best regards,
Alexey Pasumansky,
Agisoft LLC

maddin

  • Full Member
  • ***
  • Posts: 161
    • View Profile
Re: FBX Export settings
« Reply #4 on: February 07, 2017, 05:06:39 PM »
Hello maddin,

Looks more like feature request for additional export settings.

Possibly - although I still don't understand why FBX is exported as 'y up' and 'centimeters' if PS uses 'z Up' and 'Meters'. Do I need to log an official request or is this thread sufficient?

maddin

  • Full Member
  • ***
  • Posts: 161
    • View Profile
Re: FBX Export settings
« Reply #5 on: February 24, 2017, 08:23:22 PM »
Actually, having looked at this a bit more, I would rather say this is a bug:
The FBX contains incorrect scale and orientation information.

The predefined 'Front' view shows the X axis pointing to the right side of the screen, and the Z axis pointing to the top side of the screen (and the Y axis pointing into the screen). This means PS uses a right-handed 'Z up' coordinate system.  Importing this in to 3ds Max, the importer tells me that the FBX that PS created is saved as 'Y up', and since 3ds Max is 'Z up', it will rotate the data on import by 90 degrees, producing an incorrect result.

Same problem for scale: The FBX created by PS contains meta-data which says the file was saved in 'Centimeters', when really the data uses meters as units. Again, this causes an incorrect conversion.

I think this should be moved to the bug report section.

Edit: Need more proof? Compare what you get when exporting to FBX and OBJ.
« Last Edit: February 24, 2017, 08:41:06 PM by maddin »