Should I Union These Parts to Reduce Lag?

I’ve built a large tower with over 100 stairs. I’m not sure if I should union all of them to reduce the part count and lag, or if I should just leave them.

Picture of Stairs

What will reduce lag the most?
Thanks for the help and have a great day! :grin:
-TmsDevv

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Do not union those parts! That will cause more lag.

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Not only would it be redundant to Union them all, it would also make the collision boxes of the stairs entirely non-functional (edit, unless you use PreciseConvexDecomposition, which has its own performance impact).

Unless you plan on having that structure as a background asset the player never touches, and have a lot of them on a map, don’t Union it.

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This is false. Collision can be modified through PreciceConvexDecompisition.

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Do not union multiple parts - this does not stop lag. Every time studio runs the place, every individual part is loaded and unioned in the order they’re unioned in studio - it causes more lag.
Instead, you should export the parts as a .obj file, and then insert them through a MeshPart. This will instead pull the model as one object off of Roblox’s website, instead of relying on the client’s power to handle the lag.

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just to point out, 15 towers is equivalent to 1,500 stairs (not a good idea) but if you have one or three towers it’s perfectly fine but it’s going to be way better if you do what PhoenixCraft99 mentioned.

edit: if you transform the stairs into one mesh the collision will be weird so you’ll have to change the CollisionFidelity which can increase lag.

edit2: i believe it should be fine because its only one mesh but then there’s the same problem again, too many of them will impact the performance, PreciceConvexDecomposition means extra math.

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The map will have 2 towers and thank you for the feedback.

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I mean, you can try unioning the stairs if you want to reduce the lag spikes when moving them around in Studio, but unions can also be a little inefficient where they could create invisible borders, so if you want to union the stairs, I would suggest unioning them into a few parts, rather than just one solid union.

Otherwise, unions won’t do much for your game’s performance. You’d even be better off editing the stairs in Blender, if you ask me.

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Honestly I would hold off on Unioning these parts, as it would probably create lots of lag. I’m speaking from experience when I say that not only can Unioning too many parts cause lag, but it can also destroy the stairs. If you Union too many parts at once, it can actually cause the parts to become disfigured, especially if you have many small parts. Here is an example of a bad Union.

Notice the odd shapes of the would be perfect circles? Hope this helps!


Nice build by the way! :smiley: I see a lot of potential in it!