I come from an artist’s perspective to UE4, I spend most of my time either creating or hacking models in 3DS Max and furthermore skin and rig them. I’d like to make some terminology clear here, whenever I say “Rig”, I am referring to the CONTROLLERS such as IK Chains and Helpers driving the bone hierarchy, not the bone/vertices weighing process.
As I jumped into UE4, I wanted to try the asset import process for Skeletal Meshes to plan out the extents of my protyping, but I have a hard time understanding what the Engine expects of me, primarily because the errors it throws are ambiguous. I believe I am misinterpreting how the engine works, as such I would be very grateful if someone can clarify the points below:
1) When exporting the SKELETAL MESH, it should be sufficient to select the model/body parts I am interested in, alongside the bone hierarchy that drives that mesh – it does NOT matter if there are other unused bones or models in the scene as long as I indicate “Export Selected”.
2) When exporting the animation, it should be sufficient to select the bones ONLY and export them (No need to select the mesh that is being driven). Moreover, I would assume that you should **BAKE **the animation in the FBX setting.
3) Most importantly (I believe this one is causing all my issues) – My model is already RIGGED in 3ds max; that is, the bones are linked to other controllers and helpers alongside some constraints that would help me animate inside the program. My understanding was, as long as I select the BONES only and ignore my controllers, Unreal Engine will simply take the hierarchy as is. And once I import my animation (that was produced using my controllers), it would simply interpret the movement of the bone hierarchy without really caring about what’s really moving them. This goes back to my point on why I assumed you should bake the animation as well. Am I violating something by exporting a model that is rigged with controllers and helpers? It is worth mentioning that bones like the Pelvis were re-linked to a controller in the process - perhaps that could break something?
So I’d like to know how accurate are the first 2 statement, and whether my workflow in the 3rd point is valid.
To summarize, here is what I am doing to get my skeletal meshes/animations to UE4:
Acquire a fully skinned model with a bone hierarchy -> Rig the model with controllers and helpers for help with future animations -> Select the mesh and bones (without the rig) and export as FBX -> In another file, animate my character using my rig and select the driven bones and export as a baked FBX animation.
Results: The model imports in the engine, I could see it in the viewer, however when attempting to save it, I get an error simply indicating “The Asset Failed to save ();” with an error log containing an empty " " . Moreover, when I import the animation FBX, I tried to target the skeleton I imported with the mesh (It appears in the drop-down) but clicking it does nothing - it simply refuses to select it.