February 6, 2019
Buoyancy Game Concept
Thesis Physics Game Concept
This concept focuses on creating a physics-based game with a lot of variable parameters using buoyancy to guide the main mechanics.
The first focus is just setting up a script that handles adding buoyancy force to an object. This script was named BuoyancyApplicator. It has a section of variables dedicated to determining the buoyancy force (all the variables in the basic buoyancy force equation), a section dedicated to different geometry dimensions (to determine volume for the previous equation), and then other Unity specific variables (such as RigidBody component). The standard buoyancy force equation used is:(buoyancy force) = ((liquid density) * (acceleration due to gravity) * (volume of displaced liquid))All of these are variables we can alter to provide a different experience, but for the simplest version in a given scenario, we can keep gravity constant, the volume displaced will be a constant (from the shape of the object) as it will be fully submerged the entire game, and liquid density just changes when the object goes from one liquid to another.
The game will involve the player controlling an object going through different liquids, so we needed a way to account for this transition. Since we just need to change it upon entering a new liquid, I placed the update for the liquid density variable in the OnTriggerEnter, and just have the “liquids” has trigger collider areas.
In an attempt to make it more physically accurate, I implemented Unity’s own rigidbody drag factor. Fluid drag is a fairly complex calculation, so in an attempt to just mimic it simply, I set the drag equal to liquid density times an arbitrarily defined drag coefficient that is manually assigned. I am not entirely sure how Unity’s rigid body drag works, but this approach seemed to give the desired result for the most part. It was especially helpful for cases where I had the object speed up a lot going through a very dense liquid, and then slowing down when entering a less dense liquid. All of this together even worked to have the object sink when it entered a very low density liquid.