Let the user pick which animation stack to import in an fbx

[adrsch]

PR Details

If multiple animation stacks are present in an fbx, let the user choose the index to import.

Description

This only allows it to be set after the asset is initially created and imported. Also, the index is clamped so it doesn't break if you set something out of bounds.

Tested with a mixamo animation, since they set everything in the 2nd stack and a t-pose in the first.

Related Issue

Motivation and Context

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have built and run the editor to try this change out.

[manio143]

Code changes look fine. Since this is modifying the public API of the animation asset, does this scale to any other format than FBX? If so, we probably need to file an issue to get this implemented for other model importers. If not, we need to add to the property description that this is a special case for FBX and the value is ignored for other file types. Maybe even it would make sense to call it FbxAnimationStack if it's a feature specific to that file format. However, I imagine it's the case that other file formats would also support multiple animations. But would other formats also use an integer index or maybe a string identifier?

[adrsch]

Code changes look fine. Since this is modifying the public API of the animation asset, does this scale to any other format than FBX? If so, we probably need to file an issue to get this implemented for other model importers. If not, we need to add to the property description that this is a special case for FBX and the value is ignored for other file types. Maybe even it would make sense to call it FbxAnimationStack if it's a feature specific to that file format. However, I imagine it's the case that other file formats would also support multiple animations. But would other formats also use an integer index or maybe a string identifier?

I totally forgot about other formats! I'll get that added.

Ideally I feel like the importer would have a nice little dropdown with the names of all the animations, or at least limited to valid indices. Not sure how I'd implement that with the UI framework, the only dropdowns I've seen have been bound to the names of a hardcoded enum and that would probably be more annoying than an integer field.

[tebjan]

Isn't it possible to just import all and create the appropriate number of animation assets according to the names of the animations?

[adrsch]

Yeah, I think that would be possible. Maybe with a way to skip certain animations if you want, since my use case is just to use the 2nd animation and ignore the first, lol. Not sure if the names have uniqueness enforced. If they don't the index may need to be used to keep it consistent across imports.

That being said my usage is probably a bit niche since I would bet I'm the only one working with stride who is using 3DS Max... and I'm upholding as my ideal, how 3DS Max handles files with multiple animations (a way to pick which animation is imported). But hey, the scope for that is very small XD

[manio143]

Looks good. One more comment about XML comment.
Hopefully this is a simple first step towards importing multiple animation assets.

[manio143]

Can you adjust those comments, now that they're not FBX specific?

[adrsch]

Done! Yeah, I think something like the way material import from fbx is handled is very feasible.

[manio143]

@adrsch Did you not push after saying "Done"?

[adrsch]

Oh... yeah I did forget to push. Oops...

[tebjan]

Looks good, a nice first step towards importing multiple at once.