Descendant UI elements lag behind when their parent/ancestor with a Path2D is moved

When moving a UI element with a descendant Path2D, all descendant elements in front of the path (including the path) update their position at a slower rate. This is very noticeable at 60 FPS.

Reproduction:
path2d-repro.rbxl (63.7 KB)

  1. Set framerate to 60 FPS
  2. Drag the button with a Path2D in it

This happens both in studio and client.

System information:

OS: Windows 11
RAM: 12 GB
CPU: AMD Ryzen 7 5800X 8-Core Processor
GPU: NVIDIA GeForce RTX 3060 12GB

Note that I’m on a virtual machine with the GPU passed through.

0.25x speed:

Expected behavior

All UI elements are expected to update their position without any frame skips caused by the Path2D instance. If this is an optimization, it should only affect the path.

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Hi!

Could you see if this issue is still happening?

Thanks!

Yes, just tested it. Although there’s a small difference

Before:

After:

I’m not entirely sure what’s still broken in the after video. It looks like they’re all moving as one?

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They are, which fixes the original issue, but the UI still updates at a lower framerate. This is very noticeable to me at 60 FPS. I assume that it’s not a bug but a performance optimization? Why not disable it at the highest graphics setting? I don’t really see any problem with Path2Ds updating/rerendering more frequently, as I usually use studio with 240 FPS to notice any FPS drops early.

The laggy movement is only really visible at 60 FPS, so maybe the update rate can be adjusted to hide that?

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Oh you mean that the UI is behind the mouse? That’s a separate issue that’s not entirely solvable. If the Path2D issue is fixed, I’ll close out this ticket.

Alright, you can close it then. Thank you

Hey, I’m not sure if this is a known bug, but the path drifts away if the position property is not directly changed:

This for sure didn’t happen before so it must have been introduced recently.

It looks like my change did break this, I have a fix, it’ll roll out in the next couple week!

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