Physics

03 Unstable Rotation

Introduction To Section 3

Section 3 Assets

  • Section Assets Pack
  • Previous section project, for Magnus Effect

Section Notes

Unstable Rotation In Unity 5

  • The limitations of spinning objects in Unity 5.
  • Why unstable rotation doesn’t evolve.
  • How to model unstable rotation in game physics.

Introducing Inertia Tensors

  • Roughly what is an inertia tensor (I)?
  • Unstable intermediate axis
  • How Unity Calculates I
  • Calculate I for your phone
  • Predict it’s unstable axis

Calculating Moment Of Inertia

  • How about if two axis are equal?
  • Try it with a spinning cylinder.
  • Calculate the moment of inertia.
  • Render vs. collider mesh influence.

Parallel Axis Theorem

“Newton’s Laws Of Rotation”

  • A recap of Newton’s laws of motion.
  • How these relation to rotation.
  • Important differences.
  • Why we’re jumping in the deep end!

Applying Torque To Rigidbodies

  • How to use Unity’s AddTorque() method.
  • How Inertia Tensor affects rotation.
  • Comparing the rotation of two objects.

Vector Cross Products

  • What a cross product is.
  • Why they are so useful.
  • Using WolframAlpha to calculate.

The Magnus Effect

  • What the Magnus Effect is.
  • How we can approximate ball flight with it.
  • Using Vector3.Cross in Unity.

Section 3 Wrap-Up