In physics engine, there are usually two ways to model the vehicle physical behavior. One is Rigid vehicle which the idea is straight forward, it treat the vehicle body as a rigid body and using hinge to connect to wheels that model as cylinder shape. However, in reality, the wheels are not a rigid body and implementing behavior like suspension required complicated joint modeling.
The other way is Raycast vehicle, the chassis of the vehicle is still a rigid body but as its name suggest, this mechanism uses rays (invisible lines projected from a source) to detect and respond to the terrain or surface beneath a vehicle. As the rays intersect with the ground, they provide essential data points that help simulate realistic suspension, wheel-ground interactions, and vehicle dynamics, accounting for factors like terrain irregularities and vehicle speed.