Today we are going to work on how to prevent rain particle go inside shelters or any indoor area of the game. Here, we will implement a dynamic occlusion volume for rain particles that kills GPU rain particles if they enter the volume and there can be multiple indoor areas that supports the occlusion system. Even though we can add collision detection for Niagara particles to prevent them entering indoor areas, for GPU particles, collision will not work unless the blocking object is rendered in the viewport. This is the reason we would need adynamic occlusion volume method to kill GPU particles.