Description
The user stands on a barren planet, fires burning all around, with mechanical sprinklers keeping most of the flames at bay. Behind the user towers a city in the distance, surrounded by a dome. A voiceover calls upon the user to use their powers to fight the fires and repair a sprinkler that has broken. Using their abilities as the designated protector, the user can fire projectiles from their hands to extinguish the fires and clear a path to the sprinkler. Reaching it, the sprinkler reactivates, and the voiceover congratulates them. In short, the user firefights on a different planet.
Process
We started thinking about interesting, observable, everyday actions. Building upon our ideas from the in-class activity and considering the controllers of the HTC Vive, we landed on the action of waving a fan. Simultaneously and iteratively, we considered what situations waving a fan do occur and could occur inside of an alternate reality. This led us to think about firefighting with a fan. With this action and character context, we built a narrative of a civilization under constant threat from the fires of the planet they live on.
We imagined what the life of a firefighter in such a civilization would be like. A civilization under constant threat of fires would establish more permanent and secure defenses against the ever-present threat of fire. Hence, the city of the civilization is covered by a dome, and the dome is surrounded by large mechanical sprinklers. The role of a firefighter as a first-responder shifts slightly in this reality, then, as they are tasked with repairing and maintaining the defenses rather than fighting the fires themselves. This translated into the user repairing a broken sprinkler, using a fan to fight the fires which had encroached inside the boundary in the meantime.
Due to the change from a VR system to a computer system, we had to reconsider the interaction of the fan. While an HTC Vive controller mimics the handle of a fan and can be waved independently of the user turning their head, waving a mouse around in first-person would force the user’s head and aim to move erratically or require an unconventional restricting of movement. Because of these affordance problems, we changed to an earlier idea: throwing water balloons. The FPS-reminiscent setup allows a clearer connection to what user’s already expect from a mouse-and-keyboard game. Upon in-class feedback, we abstracted the water balloons into spells.
With the world, character, and interaction worked out, we moved to divide up the work and start building. Steven worked on the scene design and hand animation. Mari worked on the projectiles. I worked on the particle system interaction between the extinguishing projectile and the fires.
To create the effect of an endless fire, the fires had to burn continuously and reignite if extinguished. The reignition had to be delayed in order for a path to be cleared by the user. After exploring the asset store for different fire systems, I started to use the Fire Propagation System. I followed the use instructions, learned exactly how all of the parts worked, and realized it would not work. The fire system was too realistic. The fires in this system burned based upon available fuel and different material and climate properties. After the calculated “HP” of a material is reached by the ignition system, a fire starts, and then burns until the materials fuel value is reached. Unfortunately, we did not want a fire that would always die.
I read through the sections of the Unity reference on particle systems and collision and then found tutorials on how to script delays of actions and to disable and reenable in game objects. With this research, I was able to write two scripts. One script detects collisions between the extinguishing particle system and the fire particle system and disables the fire system upon collision. The other script detects when fires have been disabled and then enables each particle system after a given delay. With this much simpler method, the affordances of the extinguishing spells and the response of the environment is much clearer.
The scripts were combined with Mari and Steven’s work. As final touches, a voiceover was added to clarify the narrative and contextualize the user’s role in the experience, and a cylindrical indicator was also used to guide the user to the disabled sprinkler.
Scripts
extinguish script 
ignition control script
Script Demo Images
two fires burning 
water puts out fire 
fire stays put out as water moves to put out second fire 
water puts out second fire 
first fire reignites
Reflection
In the end, this experience successfully establishes an everyday activity in an alternate world. It approaches this challenge by considering a specific role, firefighter, and restructures that role in an alternate reality, the fire planet. The voiceover, hand animation, particle path, and fire system all clearly demonstrate or reinforce the different affordances of the experience. While the world and the character matched what we envisioned early on, the interaction itself lacks much of the more seamless interaction afforded by a VR system and its controllers. While the materiality and contextualization of the interaction is unique, we did not have the opportunity to explore the potentialities of a new medium, the way creating a fanning interaction in VR would have.
Agency
The main action designed for the user in Fire Planet is extinguishing fires. Its meaningful quality relies upon the instinctive perception of uncontained fire as a threat, the intuitive perception of a city as something to be defended, and the provided (via voiceover) impetus of the user’s role as a protector. The planet’s features and orientation of the user help establish these perceptions. The uncontrolled fires contrast against the fires controlled by the functioning sprinklers. The user starts close to and facing the uncontrolled fires, with the city behind them. Placing them between danger and the endangered, and having them face the danger rather than face away from it, suggests the role of a user as a guardian about to defend rather than a victim about to flee. The voiceover then makes all of this explicit through narrative, establishing a motive and a specific task, repairing the sprinkler, that will allow them to fulfill their role completely. All of these elements combine to drive the user to extinguish the fires.