AutomaticCanvasSize ignores UIPadding, UILayout Padding and UIAspectRatioConstraints

Arctic_Vibes · February 26, 2026, 7:46pm

UIPadding: (This seems to subtract from the original AutomaticCanvasSize in addition to being ignored)
UILayout Padding:
UIAspectRatioConstraint: (This seems to fail with >1 aspect ratios and/or ScaleWithParentSize)

This along with the following bugs have been present since the introduction of AutomaticCanvasSize, and have made ACS unusable without dynamic adjustment of CanvasSize:

AutomaticCanvasSize ScrollingFrame UIPadding scales off AbsoluteCanvasSize instead of AbsoluteSize - Inconsistent with UILayout padding
AutomaticCanvasSize ScrollingFrame Frame position only scales off AbsoluteSize on ACS axes - Inconsistent with ACS size scaling behavior
AutomaticCanvasSize ScrollingFrame UILayout Frames only scale off AbsoluteSize on ACS axes, overriding default ACS frame scaling behavior

It’s worth noting that UIListLayout’s AbsoluteContentSize accounts for all of these (apart from UIPadding that isn’t in the layout) and is the primary method for dynamically patching this bug.

Repro:
Repro.rbxl (73.1 KB)

Expected behavior

AutomaticCanvasSize should correctly account for all UI Elements to fufill its original purpose of saving development time from adding dynamic adjustment logic.

Arctic_Vibes · February 26, 2026, 8:03pm

I didn’t notice the UI Engine Bug category and mistakenly labeled this and all related bugs as a Studio UI Editing Bug.

DrRanchDressing · March 3, 2026, 8:22pm

@Arctic_Vibes thats ok, we have the internal ticket correctly routed to engine backlog!

We have a few of these ACS bugs reported so we might consolidate the tickets since there are a lot of dupes, will check to see if this would be possible to fix without introducing any backwards compatibility problems.

Thanks for the report!