A little late to the party, but I just wanted to show this in the thread:
Above is a fairly standard union, once you export it to Blender, you can see the horror of CSGV1.
This doesn’t even include the interior geometry that can’t be seen. Furthermore, unions, unlike parts, are treated as meshes and need to be pulled from ROBLOX servers which slows down load times.
Hence, anchored parts are the best, and then optimized meshes in place of unions if it is practical to do so. (Don’t go meshing galore for a three part union.)
If you do need to use multiple of the same union, make sure that you are using duplicates of a single unions and not remaking it each time, as each union will have to be loaded from a different asset reference.
That said, as others have pointed out, inefficient scripts will almost always lead to laggy places faster than builds.
This is actually quite incorrect. The roblox engine must triangulate EVERYTHING!
Even if the object looks like it is just made by quads, it is still triangualted faces. You can actually experiment with this and load in a part in roblox export it to blender and you’ll see what I mean. Every game engine must triangulate all objects. Reason: Idk why
What makes unions bad then? Well, it takes memory for the studio to save the data on what should happen when the union gets separated. Meaning the negative parts are parts that never gets ‘deleted’ or removed. They just get ‘transparent’.
There are no transparent faces. Render mesh, physics mesh, and data on the operations that were performed are stored separately. A complex hierarchy of operations does not have an immediate impact on rendering – the number of faces in the resulting CSG mesh does.
To reduce the amount of lag in your place I just recommend using lesser parts and unions,you should also make sure your brick terrain is using a minimum of parts as well since that’s a large load of extra bricks and parts into the place causing it to take longer with loading and increasing the amount of lag.
