Mechanic #3 Smokey Room

Mechanic #3: Smokey Room

 

There is a room with very dense fog. Normally the player won't be able to navigate inside the room without being completely lost.

However, with the help of the geometric shape mesh you see on the left of the top image, the player can navigate the foggy room. That mesh will "push" the fog away from itself thus guiding the player.

The smoke is created solely inside Cascade, Unreal Particle System. The particle was created so that it will gradually become opaque and slow fade away. It doesn't have a definite direction of velocity, but it uniformly disperse outward from its spawn point.

The particle system is changed into a PhysX Sprite. In the Content Browser, one needs to create another system in order to tweak the system even more. The PhysX particle will allow the sprite data to become interactive with the forces that are put in the world.

As you can see on the image above, there's a trigger, force actor, and the mesh. When the player touches the trigger, it attaches the force and the mesh to the player. As a result, the player gets an illusion that the mesh is moving the fog instead of the force actor. The actor's strength may be tweaked to push the fog further or shorter. And the falloff can be adjusted as well.