# What is the MOPE physics engine? These are the components of MOPE physics engine. The most important thing to note in physics engine is that linear algebra is very important. When a basketball is thrown at something- it will generally move at a constant speed The ball will also move vertically, its motions are not constant as gravity affects it Newton's equations point out that while the ball moves forward it is simultaneously moving up and also down because of gravity's influence. Points as Vectors-like arrows, vectors have a direction and they also have length. Their position in space is not absolute. When you are designing a point that is a vector, you should make the simple assumption that the vector tail is at point (0,0).

## Newton's second Law of Motion Newton's 2nd law is very important to us.

There are two reasons why this formula is very powerful. The first reason is forces can be defined as the way objects interact with each other in a real world. The second reason is you are able to calculate an object's position and its velocity if you have knowledge of the object's acceleration. You can accurately model any given physical scenario if you are able to correctly set up the forces. Calculating Velocity and Position. The relationship between acceleration, position, and velocity is helpful when programming using physics engine as if an object's history is known then it is not difficult to figure out the velocity of that object. We may also be able to calculate its acceleration by answering the question In the last few seconds, how far did this object move?"

## It’s smart to have Rigid Bodies!

Rigid bodies are known to have an orientation and shape. They are able to rotate, and can also collide with other rigid bodies. Particles are known to be point-masses. They don't have a shape nor a size. They also don't have an orientation. Particles are in fact the simplest form of physical entity to that can be modeled. A degree of complexity is added when Modeling is done on something with a shape should rotate. Collision Detection Collision detection is known to be the most complicated aspects of physics engines. Collision detection is a very costly operation an operation can have thousands of objects, a lot of effort is directed at optimizing algorithms for collision detection. Separating Axis Theorem There are two major methods used for collision detection. GJK (aka Gilbert-Johnson-Keerthi distance algorithm) -is the first method, is used commonly in 3D detection of collision as the algorithm that will be used is costly when it is done in 3D.

## Separating axis theorem is used mostly in 2D collision detection.

It is much easier to visualize and conceptualize. Collision Response Once objects are determined to collide, they must have a reaction to it of some way of reaction. Most of this will be dependent on the mechanics of the game. When a bullet is fired at a character it should cause some damage. A missile, on the other hand, should cause some damage and should than explode. For now, we'll look at a very physical response the first one is two boxes knocking into each other than bouncing away. When two hard objects collide, the momentum of the two objects does not change. Real objects are not hard to a level of perfection, so we than introduce a fudge factor known as the coefficient of restitution, which simply models the elasticity of the collision.