Usability of the FBX importer


I am little bit confused about the usability of the FBX importer…

I have written my own FBX exporter from my DCC software( using Autodesk fbx sdk), so far so good. It is able to export the whole scene (mstly static meshes)

But I don’t get some major gaps in the Unreal FBX importer, for example pivot. When exporting, i compute bbox, do a mesh transform to the local space and I use Lcl Transition to the world space,
so my meshes are placed correctly in the Unreal scene. But pivot is at (0,0,0). I have found some discussions about it, it is a known issue, but i have following questions:

  1. bounds are wrong. everything is still working, but are there some implications? performance? Is it used for some in-engine sorting etc? my meshes are hundreds of meters far from the origin, so the bounding sphere is huge.
  2. what is the workflow in existing games? nobody is constrained with this? really ale projects import all meshes to origin and do a placement in editor?
  3. what about some custom data, that may be transfered through the fbx? no support for it? nobody is using custom data passed between dcc and unreal?
  4. what abouty collision mesh? nobody is restricted with the limitation for fbx with multiple meshes?

sorry for questions but I am probably missing something, because i don’t understand how fbx importer can be used in large scale projects, but i looks that some games were definitely released with these constaints :slight_smile:


When you import something to UE4 the pivot will be placed at the origin, so when you export you need to move all objects to 0,0,0 so that the pivot is located where you have it on the object. When you import to the content browser in UE4 the original location of the object in your scene is irrelevant so if your goal is to get the objects placed where you had them in your 3D application without the pivot being moved then you need to use the FBX Scene Import option:
That will import the objects with their correct pivots along with maintaining instancing and will allow you to create a Blueprint which you can drop into your scene and it’ll have all of the objects placed like they were in your 3D application.
There’s also the Datasmith plugin for UE4 which is currently in beta which has a one-click export from 3ds Max to UE4 that will place the objects and will export things like lighting and convert materials from Vray and other renderers to UE4.

thanks, it looks that scene import solved my issues, i was not aware of the difference.

only one small issue remains, i can’t find global scale parameter as in normal fbx import, but it can be scaled in the exporter.