Long story short, let’s say I have a tree with animated leafs, and I have a bunch of them duplicated and running in one game. Will this cause performance issues?
That all depends on how you are implementing these animations, how detailed the trees are, and how concentrated they are in your workspace. There are definitely many ways to optimize such a system to be more performant. For starters, you should run animations exclusively on the client and only animate what is immediately visible to the player. You can also play around with using different methods of animation, tweak any parameters relevant to the animation and see what performs best.
If its a huge map and the client has to process the leaves everywhere on the map, even those that aren’t nearby and are just 3 km away which the player can’t see but the system processes anyways, yes, its going to be a problem.
There’s methods game devs use to make leaves be detailed, one of them is to render only that which the player sees, not what the player will see.
I can’t find useful info, here’s something of what I mean. This is what game devs do to the system so it renders fine.