Sunday, August 6, 2017

c++ - What is the difference between an impulse and a force related to a physics engine?


What is the difference between an application of an impulse and an application of a force in relation to a physics engine?



Answer



An impulse is applied instantly, so it does not depend on the time step. You would use an impulse when you want to give a fixed boost of speed to something, or the physical action happens too quickly (ex. bullets/gun ricochet, collisions, jumps, instant speed ups).


Meanwhile a force changes the speed directly proportional to the time step. You use it for things that have an over time effect (ex. gravity, long springs, air resistance).


Mathematically impulse = force * time; And for reference impulse = mass * velocity_change, force = mass * acceleration.


If you expand the first, you can check this:



  • impulse = force * time ->


  • impulse = mass * acceleration * time and since acceleration * time = velocity_change ->

  • impulse = mass * velocity_change.


No comments:

Post a Comment

Simple past, Present perfect Past perfect

Can you tell me which form of the following sentences is the correct one please? Imagine two friends discussing the gym... I was in a good s...