Best approach to mass spawning with physics

This is my first game. It’s based on the top-down template and I am using blueprints as I am an artist. The main activity of the game involves the player spawning dozens of different low-poly objects. For instance, you can make a pile of rocks and then destroy the pile in various ways such as blowing up the pile, pushing the objects around, freezing them (turning physics off), etc.
I’ve started by making the rocks and other objects as blueprint actors. I use the character blueprint to spawn the rocks using an ‘event tick’ to ‘is input key down’ then branching to ‘SpawnActor’.

But when the player spawns even a few dozen rocks, the whole game slows down. Any advice on the best approach to creating this game? I can rebuild it fairly easily – my question is what is the best way to rebuild?

Do these rocks BP’s have some functionality in them except for standard engine physics?


Do you launch the game in the viewport or as a standalone? I’ve had a similar issue recently, and I believe that when you launch it in the viewport all the blueprints are being analyzed for debugging purposes, even if you don’t select any object to debug. I’ve experienced massive frame rate droppings to 30-40 fps, but if I launch as a standalone, fps maintains at 400-500.

Did you disable ticks in the rock blueprint? You should.