The engineer didn’t say mesh parts always provide big memory usage benefits compared to parts, they very specifically categorized the use case as
The post also says that properties have to be stored, not their geometry, unlike meshes which need to have their geometry stored. For complex meshes, mesh parts may be better for performance, however, when comparing a mesh vs Roblox primitive part, this is not the case.
When he says this, he is not implying that parts work in such a way that their geometry data does not need to be stored. He is explaining why 16,000 parts will take up more memory than 1000 meshes with the same total geometry - he explains that this is due to the fact that each individual part will take up memory because they are each individual objects with many different properties that need to be stored. He has to make this clarification of “nothing to do with their geometry” because many users earlier in the thread make claims of the performance difference having to do with geometry being stored differently or taking up different amounts of space.
I mean… you could just set the collision to Box and even make it CanCollide false then place a few transparent parts for the bounds of the mesh.
You would get the same result from just keeping CanCollide true while having box collision.
Placing transparent parts around the mesh would be highly inefficient.
Highly inefficient in what way exactly? I’ve considered several methods for sparing memory and processing. It’s much better than having every complex mesh set to ‘PreciseConvexDecomposition’, which eats up the GPU when the player’s within range of those meshes. This is a good alternative to that since parts that are transparent aren’t rendered and don’t take up any GPU.
Example
You have an archway mesh and the default bounds are kinda jacked up, so you opt for more precise bounds, that’s going to be a lot worse for performance than setting CollisionFidelity to Box, set CanCollide to False, then have a couple of transparent parts act as the bounds. You’re basically making a hitbox.
Well, in your case doing that would make sense, but it really depends on the complexity of the mesh and whether or not having all of those transparent parts would be heavier on performance.
With a very complex mesh, it might be better, but having a low poly mesh and still doing this would just add the small performance impact from those 3 or 4 transparent parts, while the geometry of the mesh is low enough that having precise collision would yield the same result.
I agree, i’d only do this with meshes that have jacked up default bounds as it’s unnecessary otherwise.