Question VFX particles extremely slow when getting close to them

Hi.

I'm using VFX Graph on Unity 2021.3 and URP.

Here's a tornado from a relatively far distance:


FPS is good, but when I get closer to it, it gets absolutely terrible:


I understand that it's kind of related to the particles taking a large portion of the screen, so I can kind of avoid it by reducing the particle scale as I get closer, but this would totally ruin the look of the effect.

What can I do to keep it as fluid as when I'm far away from it?

Thank you

 

Can you check the profiler and send a screenshot of the hiarchy both from far away and close up

 

Turns out disabling "Cast shadows" fixed it. Since this tornado is an unlit graph, I don't need it anyway...

I'm soon going to upgrade the system to a lit graph so I'll see what I do then...

 

Unlit meshes still can cast shadows. That means you have thousands of shadow casters, so that definitely will be heavy. You can better fake this with a mesh set to cast shadow only.

Making it lit will also make sure all the lighting calculations happen on all meshes, so I suggest not to do this haha