Play particle in a specific area

Just asking, how did GPO make this effect where they played a particle emitter if the rock I’m using to fly is near a part and it would play the emitter below me and in that part?

https://gyazo.com/66957c01ebe22e218335146340c9a795

Parent the particle emitter to an attachment then offset the attachment down.

what if it doesnt stick to the ground

Cast a ray downwards from the rock and set the WorldPosition of the attachment to be where the ray hit the ground.

how would I do that exactly? sorry I haven’t learned raycasting.

I suggest making the looped raycast in a local script. To not make the local script messy just have a module script in it. There tell the module script when to stop or start the script so you wont have to spam a remote event for it.