Is it better to use meshes, unions, or lots of parts?

So I’ve heard that unions are laggy so you shouldn’t use them but I should just use multiple parts. But in some cases, I want to curve my blocks and make custom models. Is it better to use custom blender meshes or unions for less lag?


Honestly, I would recommend meshes if you’re going for complicated objects, unions for simple objects that you just need to quickly make, and parts for normal basic things that can be done without meshes (parts are pretty flexible in what they can do).

Don’t worry too much about performance unless it begins becoming an issue in your game though. As long as proper scripting is put in place/no unneccessary infinite loops/etc, then you should be mostly fine.


I’d roll with meshes imported from blender; unions created in studio are pretty limited in terms of versatility and have a chance to corrupt (an issue where it won’t appear in studio, even if you save it).


A protip is to union all the parts that are non collided and have the same properties otherwise (and also don’t have surface inputs). This way, if you union like 300 parts it saves a lot of lag since unions can reduce lag in some cases. Imported meshes are likely the most reliable solution but try to use basic parts if you can.

To recap:

  • Use basic parts if the build is pretty simple or meant to align specifically and be an exact size
  • Use unions if you have a lot of the same noncollided parts with no surface materials and the exact same visual properties otherwise
  • Use meshes from 3d modeling softwares if the build is big and complicated and requires unique shapes

Meshes for high poly models.

Unions for high object, but low poly models.

Lots of parts just creates lag.

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