Custom bool attributes in FBX export

Hi there,

I am trying to export a mesh for use on the 3D Viewer app on the HoloLens (2nd gen). Microsoft have come up with the perfect way to control whether an object should be displayed as life-size, in contrast to being scaled to some “comfortable scale”:

To prevent scaling of the model, add a Boolean custom attribute to any object in the scene named Microsoft_DisableScale and set it to true. 3D Viewer Beta will then respect the FbxSystemUnit information baked into the FBX file. Scale in 3D Viewer Beta is 1 meter per FBX unit.

Here’s what I tried:

  • Create a custom property on my object in Blender, set its value to True, which - I think - basically makes it an Integer. From what I can see in the FBX Binary gibberish, it seems to be exported as an integer.
  • Use elem_data_single_bool in the fbx_data_object_elements function of
  • Use elem_props_template_set in the fbx_data_object_elements function of (I have no clue what the difference is, just a shot in the dark)

Neither of this got the HoloLens to do what I want. Any idea how I’m supposed to get this boolean in there? As much as I love Blender, I’d also be open for other tool recommendations that allow me to add such properties to an existing FBX or whatnot.

Thanks in advance!