I have alot of custom particles in my game and noticed a huge drop in performance after the Tough Break update hit.
I was forced to remove alot of collision particles and optimize the particle effects.
I recommend that you don't use alot particles with collisions since they seem to be borked at the moment
But if you still want to have rain collide there are a few optimization things you can easily do in the particle editor
- Emmiters > Emit continuously
Decrease the emission rate to lower the total particle count
- Constraints > Collide with world
Increase the "Trace accuracy tolerance" to 256 or higher. It will make the collision detection more inaccurate but it won't really be noticeable(assuming you don't have paper thin walls)
You can also set it to collide with brushes only. You can then use block bullets or nodraw to give rain collision to important/big props.
On the mapping side of things.
- Don't have the rain particle active 24/7
Use a toggle or a rain particle without collision on inactive areas such as payload stages and foward/back spawning that leaves a portion of the map unused
- Make sure that the particles "aabb" box aligns properly inside brushes/visleafs.
I am not too sure how or even if this will help. But I am confident that some sort of visibility culling takes place. If you do try this out tell me the results, I am trying to figure this one out as well.
"cl_particle_show_bbox 1" is your friend
- Don't use vphysics for every prop, the block bullet trick is better instead. A simpler collision mesh will help (Not as impactful as the rest, but every bit helps)