Semi-transparent Unions Effect

I have been trying to make a window from a complex shape, and my first call was unions. I made the window, and it gave similar results to this:

If anyone has any idea how to remove this effect without having to slightly overlap the two blocks, I’d be very grateful to hear how.


I believe glass can greatly reduce the occurrence of this effect, though not entirely. I don’t think it is possible to eliminate this when using unions.

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Although I’m not sure if this will work for CSGv2, you can try this:

If that won’t work, try grabbing & dragging the wedge onto the bottom part so it “sticks” to it better.


Tried your method. Works from a short distance but longer distances it becomes buggy.
Plus I dont want the texture.

Didnt work on both ways suggested. Copy/pasting position coordinates and the dragging method. Thanks anyway.

Have you tried using CSGv1? I downgraded to v1 after v2 was problematic in this exact scenario.

If you’re not a fan of v1, I recommend taking the size of the part and adding .001 to the size as it very slightly overlaps it.

Might I ask why you want the glass to be this specific shape? You can typically get away with just one part, with the unwanted parts of the glass being hidden by the wall its fitted into, if that sounds like what you’re trying to do that is.

Nope. I have no clue what that is either. Please explain.

The glass will go in the gap in the wall, but as the goal is set back into the wall, it causes issues.

You can import everything in the picture into Blender, and create a custom window shape that fits what you need, then re-import it into studio. On import, it should be positioned in the exact place you intended it to go. If not, you can multiply the X and Z values by -1, which should put it in its intended position.

I consider unions bad practice, even if they are convenient sometimes. It definitely doesn’t hurt to know a little about modeling if you don’t already.

I have no experience with blender. Even starting with this would be more difficult then it needs to be. Thank you though.

The issue is that the Union calculation can get a little messy sometimes:

You can see the redundancies if you export the Union into a 3D program:

A few possible solutions are:

Play around with Part configuration for the Union, eventually there will be a rotation or combination that won’t cause these inner faces.

Unfortunately Roblox doesn’t allow you to edit Union faces individually (they aren’t a pure 3D object software, after all), so you have to get creative with some work arounds.


After only recently getting into modeling myself, I will say it doesn’t take long to learn how to do simple jobs like this. I would definitely recommend just learning movement controls, and some of the simple hotkeys like fill and extrude. It really can be a really useful tool that helps you get the precision and optimization that CSG can’t offer.

Can you pm me a copy of that. I need that for a game
Also Nice post piericky i had the issue lol.

Thanks for the help. Ill use this later.

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You can make it yourself, just place three Parts together and click Union :sunglasses:

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