Hierarchical FBX Importer

[Aggror]

Summary

Our community has voiced concerns about the current handling of FBX files within our engine. The main issue is that FBX files are imported as a single model instead of being split into multiple entities, respecting the original hierarchy as structured in their 3D package. This discrepancy hinders workflow efficiency and limits creative flexibility, impacting both game developers and artists.

Proposal

We aim to develop an enhancement for our engine that introduces a much-needed feature: the option to split an FBX file into multiple model assets based on its internal hierarchy. When this toggle is activated, our engine will not only split the model but also automatically generate a prefab that mirrors the original hierarchy found in the FBX file. This approach will significantly streamline the asset integration process, fostering a more efficient and intuitive workflow for our users.

Objectives

• Develop a Toggle Feature: Users can choose how FBX files are imported—either as a single model or split into hierarchical entities.
• Automatic Prefab Creation: To further automate the process, the engine will generate a prefab that preserves the original hierarchy of the FBX file.
• Documentation: Provide updated documentation to ensure users can easily adapt to and leverage the new feature.

Funding: $700,- USD

https://opencollective.com/stride3d/projects/hierarchical-fbx-importer

[Noah7071]

Hi @Aggror. can this issue be assigned to me to take care of!

[noa7]

Can I suggest against the toggle feature to combine or not combine mesh at import. Instead always import hierarchy as replica of source file. It will help prevent bifurcation in pipeline, and user point of view do it once in modeling tool wether to export fbx as merged or single. From what I see thats how usually it in other game engines as well. Please suggest!

[Eideren]

What do you mean, Unreal doesn't build blueprints or scenes out of the imported file so hard to compare, and unity can discard the skeleton depending on the import settings. Changing this would be a major breaking change anyway.

[noa7]

In Unity for instance(AFAIK) the imported asset hierarchy is same that of source file. If to merge all, thats done by chaning the source file(fbx) in modelling tool or through scripts at runtime?

P.S. I'm strictly talking of mesh hierarchy, not the skeleton, material or other referenced in fbx

[Eideren]

So, every individual mesh contained in that file would be split into its own file ?
Right, so there are conflicting issues here

• either they are always split into individual files that way they can all be added as individual entity to the prefab, but then you have the issue were the model import settings does not have the concept of a specific model source at the path set, just the source path.
• or you import it as one model file and then you can't really split them into individual entities in the prefab you want to make

It kind of sounds like we're creating something truly awful here, let's take a step back and have a concrete proposal as to how this should be designed instead.

• Should this be a new type of asset ? Were it hosts multiple assets within itself, that way the asset could just point at the fbx and create asset children which map to the different objects the fbx contains
• Should we merge it into a single model but then have a submodel component, that way the user can use the model as a whole or as individual pieces ? We would still import a full model, but the prefab would be made out of those submodel components
• Have all of this as a skinned mesh instead, were each bone is an individual model, the skinned mesh would need some way to read back from the hierarchy to move the bones since Stride's bones are internal to the skinned mesh component
• Something else ... ?