Unity3D: Introduction to Physics

This article covers how Unity applies physics to game objects.

When developing a game, it is key to know how game objects interact with each other and how to program specific actions when those interactions take place. We refer to the behavior between game objects as the physics of the game.

[Note: The following information is referenced from docs.unity3d.com.]

Unity uses colliders to determine the size and shape of a game object. Colliders are created through creating rigidbodies for a game object.

To create a rigidbody, open a new game object and select sphere. At the bottom of the inspector, click Get Component and select Rigidbody.

If we leave gravity selected, we will see the the sphere fall through the window.

In summary, the rigidbody has all of the physical properties of the game object while the preceding collider contains the behavior when collision occurs. Notice the trigger option in the collider? This will be enabled so future actions can be programmed when different game objects collide.

The next article will cover two types of collision that Unity contains to determine the behaviors of its game objects.