AnimationBlendTree UX improvements

[samsface]

Describe the project you are working on

A 3D game involving a lot of characters with a variety of dynamic animations.

Describe the problem or limitation you are having in your project

The graph interface is lacking basic features that make using it clunky.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

I propose we add the following features:

• dragging nodes on edges to create interval connections
• search dropdown for animations
• consistent gui controls on Nodes (e.g. the TimeScale node has a horizontal scroll while BlendSpace1D does not)
• Some color coding of nodes
• Have a context menu for when nodes are selected that includes (copy, paste and show documentation)

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

This rough mock-up covers most of the features I'm proposing to add.
The colors chosen are random by me. I like green for animation as it reminds me of green for geometry in blender geo nodes. No opinion on the colors other than we need some form of color coding.

If this enhancement will not be used often, can it be worked around with a few lines of script?

This enhancement would be used often. BlendTree is often the core of any dynamic 3D animation workflow.

Is there a reason why this should be core and not an add-on in the asset library?

The AnimationBlendTree node is part of the core engine. It wouldn't make sense to create a competing BlendTree node that's just a better UX.

[Calinou]

Did you try GraphEdit in 4.3.rc2? It received an overhaul compared to 4.2.2.

• copy and paste of nodes within the graph editor

This is already being tracked in #8146.

[samsface]

@Calinou thanks for pointing that out. I somehow didn't find that in the open issues. The PR for copy paste looks like it's ready so can strike that from this proposal. The PR godotengine/godot#83518