Did not see this asked yet... AddForce to to current direction of movement.

Questions & Answers
1

I am trying to figure out a way to AddForce to a rigidbody according to its direction of movement (not rotation)

For instance, I have a player rigidbody moving at a speed of 20u/s forward and 5u/s to the right but facing toward the rear. How can I AddForce to his current forward and right direction of travel independent of where his camera (or other controls) are facing?

Thanks.

2

You can do:

 rigidbody.AddForce(rigidbody.velocity.normalized * someForce);

Or if you just want to increase or decrease speed by some percentage you can do:

 rigidbody.velocity = rigidbody.velocity * factor;

…where ‘factor’ is some value like 1.1 or 0.9.