For years all of my slices looked like this and I didn’t even realize lol.
This update is phenomenal. Editing 9 slice images will no longer have to be a guess and check process and this simplifies UI workflow greatly.
The only issue I have is the editor window doesn’t scale its contents when the window is resized, so it’s a bit hard to fine-tune images.
So simple, yet so helpful. I knew that this day would come, I’ve been waiting for it and here we are champs,
finally an update I can truly relate to.
awesome!!! So excited to use this
This is amazing. Thanks so much for this!
What was once a nightmare became the most simplest thing. Good job!
YEEEEEEEEEEESSSSSSSSSSSSSSS LEET’S GOOOOOOOO
Oh the struggles of manually calculating this are over!
Yes, you are correct, the 9-Slice Editor is implemented as a Built-In Plugin using Lua. However, the “…” button in the SliceCenter property is implemented using Qt.
Oh my, this was unexpected but also really useful. 
This will be so useful! It used to be such a pain to switch between studio and my photo editor to get the pixel coordinates. 9-slice images are often under used in Roblox UI, I bet this will help!
yes i’m always be in properties even though got amount of 9 slices in studio probably pretty cool, how they just i so proud editor slices that lovely support for studio for feature
I’m guessing the ... fires an event somewhere in Lua? I can probably find it lol
EDIT Found it almost straight away, GuiService.Open9SliceEditor
Great! This will be very useful.
OMG! This is an amazing update! I can’t wait to try out this feature in my development!
YES! FINALLY THE HOURS OF PAIN I HAD TRYING TO 9-SLICE IMAGES IS GONE! THANK YOU ROBLOX!
Very excited to use!
Is there a list of functions like this we can call?
I’m not sure if I’ll be using this personally, however I do see a lot of uses that could come up. Great work!
I remember suggesting this in the developer tools survey a while back, I’m really excited to see this finally being implemented. I’ve always had a hard time understanding 9slice (using it was like hoping to get something desirable after entering random numbers) so I can’t wait to update my UIs to make use of it properly 
Could the 2 draggers for each axis have colours different to eachother? Vertical would have something like red and green, same for horizontal so you can tell which one is which
Another useful update for Developers again. Thanks Roblox 
We have been blessed. I could never understand how to use the slice property correctly, but always needed it for GUI designs. This editor will be incredibly helpful. Thank you!
