# Do I need to learn any physics if I use a physics engine? [closed]

Complete novice out here. Of course I know basic physics like mass and inertia. I don't want to make an engine I just want to make a game and use a physics engine made by someone else.

Do I need to learn any physics if I plan to use a physics engine?

• I wouldn't be enrolling in Harvard any time soon... But if you know basic physics and want to use unity3d/2d physics then you will be fine. Unity has built in functions that can addforce and turn gravity off etc etc... Don't stress, just get in there and start playing around Nov 6, 2014 at 22:09
• I think a little understanding of physics will be necessary to achieve a degree of realism, but if you are just looking for something like Mario Bros even that shouldn't be necessary. Nov 6, 2014 at 23:13
• @Savlon - Which of these topics I should learn? khanacademy.org/science/physics Nov 7, 2014 at 13:21
• @Pieter Geerkens - Which of these topics I should learn? khanacademy.org/science/physics Nov 7, 2014 at 13:23

## 3 Answers

Bare minimum you need to know how the physics SYSTEM works within the engine. Most of these may sound daunting but it's really not that difficult and you CAN simply stumble through things but it will make it significantly easier if you understand these going in.

• What is a RigidBody?
• What is a Collider?
• What is the relationship between the two?
• How is it different when a collider is used as a Trigger?
• What callbacks get made, when, and which object is it called upon?
• What is the significance of something being Kinematic?
• How can you manually update the position, direction, etc of a GameObject that is currently under the influence of physics?
• What's the difference between Drag, Angular Drag, Friction?
• What influences Bounciness?

These are extremely helpful. Knowing these you should be able to get around the physics system in Unity pretty well for most tasks.

Other things to consider:

• Vector Math - It really does help to fully understand direction, magnitude, normalizing, etc...
• At least on a conceptual level it's a good idea to have an understanding of Velocity and AngularVelocity.

Knowing a specific formula or in-depth physics knowledge isn't necessary under a great many circumstances. However, it IS possible that you would need to know some in-depth mechanics in order to accurately replicate real life.

I would recommend starting here:

• Which of these topics I should learn? khanacademy.org/science/physics Nov 7, 2014 at 13:20
• @discussedtree Since you're going to be using Unity, being able to answer the questions presented above (i.e. by reading the Unity documentation, by finding a Unity physics tutorial, or by simply playing around in Unity) would be much more helpful than going to Khan Academy. Nov 7, 2014 at 14:43
• @discussedtree At the bottom of my post are two links. That should get you started. Nov 7, 2014 at 15:47

From my personal experience, some basic physics knowledge can help a lot to tune your game.

Lets say that you want to create certain physical effect in your game e.g. players can push boxes. Of course, you need to tune certain parameters to make this effect behave as you want, so that the boxes neither violently fly in every direction neither are almost impossible to move.

You can try trial and error, but besides being a boring way to tune parameters, it will make your code brittle: if something goes wrong, you won´t even know why.

On the other hand if you know how physics work, you can easily do the math and plug in the values to achieve the desired effect.

TL;DR: If you want to provide any physical effect in your game, it helps to learn the basics.

• Which of these topics I should learn? khanacademy.org/science/physics Nov 7, 2014 at 13:23

I think it's enough for you to know how gravity and forces work, although you actualy don't have to know these, because physics engine does everything for you(ESPECIALY UNITY).

Like the first komment says, just play around and learn how to use the engine.