Unity Game Optimization - Third Edition

Mass

Mass is stored as a floating-point value under a Rigidbody component's mass property, and documentation on its usage has changed a fair amount over the years due to updates in its physics engine. Since late Unity 5, we are essentially free to choose whatever we want the 1.0 value to represent and then scale other values appropriately.

Traditionally, a mass value of 1.0 is used to represent a mass of 1 kilogram, but we could decide that a human being has a mass of 1.0 (~80 kilograms), in which case, a car would be given a mass value of 15.0 (~1,200 kilograms), and physics collisions will resolve similarly to what we expect. The most important part is the relative difference in mass, which allows collisions between these objects to look ...