I’ve noticed a few issues, that happen every time
If you attempt to union a part then try to change its smoothness it crashes.
Consistency: 100% of the time
Unioning 2 models together sometimes give a darker weird shading issue.
Consistency: 75% of the time
Thank you for posting the file. Good news: I’ve checked it on the current dev build and it works fine 
So this type of bug should be fixed in the next weeks release.
Thank you for the detailed and quantified observations! We are on it
We love to see it! I’m glad this was fixed. I’m going to try it out right now, I’m excited!
can we have 3d models with more than 10k triangles aswell?
also union meshes to regular parts or meshes to meshes?
Please don’t make it server-sided… you should be able to do CSG scripting on the client.
This is really since some unions would take like 30 seconds to union and now they re real fast. Also the fix for corrupting unions helped me a lot since now I wont nees to learn blender
This is an awesome improvement: Unions have always been said to be “unreliable” and “slow”, but this fix will eliminate both those problems. With a speedy union time, bulk execution is finally possible, and vanishing won’t be an issue.
(Thank you roblox!)
I assume this applies to scripts that use UnionAsync() and SubtractAsync()? or is this just for the studio toolbar tools?
When it is out of beta, it will be.
alright, popped itup in studio, and; theres still some artifacts with the unions (i understand that this example will most likely never actually be used in a game) but it’s certainly less extreme than infinite stretching
https://gyazo.com/3ec73f64330983837c5bfc26e99b39dd
Is alluding to the possibility of support for CSG and mesh parts? Is that planned?
Please please please support meshes! that would make csg amazing and so much more usefull. we could finnaly be able to import meshes, and have a good workflow!
I can’t wait to enable this beta feature! Sometimes when I make CSG operations they either take hours and hours or they fail halfway through because “not enough RAM” (i have 32GB). This will definitely help a ton.
I also can’t wait for meshes to be supported with CSG.
Whenever I try to union something together it just says StartProcessException and crashes Roblox Studio.
It only happens on a few unions and I have no idea why.
Edit: It seems to happen everytime right now.
The post didn’t specify a lot of things but-
YES the bug that I’ve ran into only once is fixed!
Could you tell us more about this? Looks nice so far.
Excited to see this being implemented, I have always hated working with unions solely due to the slow system. However, can we expect more scalability to unions? As in being able to scale them on a specific axis like meshparts.
I’m glad the issue with union corruptions was fixed but like others are saying studio will crash when you union a bunch of parts together.
I had 24 parts selected in a stair formation and bam, unexpected error and studio crashes.
Now I also get the CSG error code -3 because ‘something went wrong’. This time, the structure is in a checker pattern. Only 12 parts, unchanged orientation size and color.
There is quite an amount of bugs here but I am ultimately glad that the CSG engine is faster and no more union corruption. 
