Currently in Roblox, UICorners always apply to all four sides, and the only way to work around this is to use spliced images or multiple different frames with multiple UICorners.
This is extremely inefficient due to other languages (like CSS) being able to apply a corner radius to individual corners, along with the ability to make the radius different for each corner if they wanted to.
This feature would be extremely useful so that developers don’t have to use such hacky workarounds and instead just use a built-in engine feature that would save time and be more efficient.
All the current solutions also come with greater downsides than just being annoying to use.
- Using a spliced image: The corner effect is a lot less sharp and requires a lot of time to set it up correctly
- Using Multiple Frames: The corner effect is sharp; however, transparent frames wouldn’t work with this at all due to stacked frames (to hide the other corners).