Pingpong loop animations in AnimationTree looping as if they were Linear

[ithiro]

Tested versions

Opening the project in Godot 4.5 resolves the issue, so it was something specific from 4.5 -> 4.5.1.

System information

Godot v4.5.1.stable - Windows 10 (build 19045) - Multi-window, 2 monitors - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3050 (NVIDIA; 32.0.15.8142) - AMD Ryzen 5 5600X 6-Core Processor (12 threads) - 15.94 GiB memory

Issue description

Animations in AnimationTrees, specifically in BlendTree nodes and connected to Linear-loop Animations through Blend2 nodes, even if the blends are set to zero, loop as if they were linear.

Steps to reproduce

1. Import an animated .glb 3D model from an external program like Blender to a project, instantiate a scene from it;
2. Add an AnimationTree to it, and add a BlendTree Node to it;
3. Inside the BlendTree node, add two animations, one set to linear loop, and another set to pingpong loop (as set on Import settings), and connect the two with a Blend2 node;
4. See that even if the Blend2 blend is set to zero, the Pingpong-loop Animation will play as if it was set to Linear-loop.

Minimal reproduction project (MRP)

N/A

[tetralyte]

I can recreate this behaviour as well and made an MRP for it here:
https://github.com/tetralyte/godot_4.5.1_pingpong_bug

Seems like even using a single node inside the animation tree without blending it gives the same linear behaviour where a ping-pong loop should occur. Opening the project in 4.5.0 yields the correct animation. Issue was noted here as well: #111719

[AThousandShips]

Can you test in 4.6.dev1, or build from source to confirm if this is occuring only in 4.5.1

It happening in 4.5.1 and not 4.5 means it's due to some cheery picked change, might be only part of a fix made it into 4.5.1

[ithiro]

Can you test in 4.6.dev1, or build from source to confirm if this is occuring only in 4.5.1

It happening in 4.5.1 and not 4.5 means it's due to some cheery picked change, might be only part of a fix made it into 4.5.1

Can confirm it does not happen in 4.6.dev1

[AR-DEV-1]

Can confirm it does not happen in 4.6.dev1

I confirmed in 4.6 [1e9d0ff] custom build for the other issue [#111719]. Aren't these two related? (The other one is also for Ping Pong loop)

[Tio-Henry]

I have this problem too in Godot 4.5.1