Does unioning parts reduce lag? Also, will making a union a mesh part reduce lag?

I’ve worked with several developers in the past and they all seem to union parts very often, not just to organize, but to reduce lag. Does unioning multiple parts actually reduce lag or is this just a myth? And my second question, will making a union a mesh part reduce lag?



Depends on how you go about doing it. Generally, yes, unions do reduce lag by reducing the concentration of parts in a given area.

HOWEVER, if done incorrectly, rather than optimizing, you’ll be creating more headaches and possibly more lag. This can happen if you attempt to union multiple complex parts together into very complicated shapes. Take for example super detailed weapons made of unions of which reach near or at the given limit. Duplicated amongst all players. At that point, you’re better off converting it OR making it from blender/modeling program to optimize it significantly and at the same time, give it the proper textures to reduce adding unnecessary details.

This is not to also mention that although union collisions can be mostly solved by switching to preciseconvex thingy colision type (forgot the name lol), switching it to it will definitely drop the performance atleast somewhat, if done this repeatedly, it will probably reduce performance by quite a bit.

TL:DR, Unioning simple parts together to reduce part concentration is fine (take not I said concentration, not count). Unioning complex parts together might not be so fine.