ParticleEffects and Collision, Suggestions?

Hello Everyone, Sadly I don't have code for this yet but was wondering if anyone had any ideas to create a particle effect and have it rise like gas and when it hits a collider the particle moves out of the colliders way so that the gas can still rise. Reason I'm asking is that I am creating a fire emitter but when it hits the collider, it goes through instead of me wanting to go around the collider and have it rise. My first option is creating a pathfinding script and give it starting point and ending point of where fire begins and fire ends. Anyone else with suggestions?