Huge number of attached actors - poor performance

Hi! I am creating a game where player can build a car by attaching parts. There is also an engine to build, that can be also attached to a car. And that’s a lot of actors to attach… There are around 50 parts to attach, and another 50 for the car’s engine. Parts are just simple static meshes. On EPIC graphics settings I get around 80-90 FPS when all parts are detached (they are still present in the level, they just lay on the floor), and around 180 FPS when graphics is set to low. However, when I attach all the parts (around 100 attached actors), and move the car, performance drops pretty noticeably. I Get around 60-70 FPS on EPIC, but on LOW settings I get only 80 FPS (180 before). That’s a huge drop I think.

What I did:

  • Child actors collisions are disabled. It helped, but not much.
  • I set “Use attach parent bound” to true, it also helped a bit
  • All the actors are NOT ticking
  • I am disabling car’s physics when it is far from the player

What can I do to increase performance in that case? Is it even possible? Thanks!

I know this is old, but I had a simlar issue making a hover vehicle. I found a lot of my meshes had overlaps enabled and were calling thousands of overlap events every tick. After i fixed it all the project went from 90fps to 300fps with 5 vechicles racing. I was also rotataing all the actors on tick as well. So that didn’t help.