(See the best response by F0lak.)
width = 500 // 500 x 500 image to cover a moderately sized map
height = 500
count = 2500 // 2500 particles
spawning = 12 // 12 new particles per 0.1s
bound1 = list(-1000, -300, -1000) // end particles at Y=-300
lifespan = 600 // live for 60s max
fade = 50 // fade out over the last 5s if still on screen
// spawn within a certain x,y,z space
position = generator("box", list(-300,250,0), list(300,300,50))
// control how the snow falls
gravity = list(0, -1)
friction = 0.3 // shed 30% of velocity and drift every 0.1s
drift = generator("sphere", 0, 2)
screen_loc = "CENTER"
particles = new/particles/snow

client?.screen += new/obj/snow

Problem description:

I am trying to get a better understanding of how the new particles work.

This is the code from the reference on particles.

The current issue is, the snow only covers a 5x5ish area in the middle of my view port instead of covering the entire screen as I'd like it to. I've tried adjusting the values and can't seem to get the snow coverage to increase in size.

I'd like to get a better understanding of how this works so I can then make a nice looking rain and create cool ability effects using particles.

Any advice? Thank you!

Still have not been able to figure this out. Anyone have any ideas on how to make the snow effect cover the entire screen?
Best response
You're wanting to modify the width and height parameters. To make the effect cover your whole map you'll want them to be equal to or greater than world.icon_size * client.view