5-physics in game (game development - umt spring 2017)

PhysicsinGame

FROM:HAFIZAMMARSIDDIQUI– COURSE:GAMEDEVELOPMENT– INSTITUTE:UNIVERSITYOFMANAGEMENTANDTECHNOLOGY

GamePhysics• Game physics adds laws of physics into a game

• Close approximation of real physicswhich is implementedwith discrete values

• Update the state of objects based on physical calculations

• Computemotion of objects in a scene

• Computemechanical interactions between objects in a scene


KinematicsandKinetics


Kinematics• Study of the motion of bodies without considering the mass and forces acting on them

(ignoring the forces that cause the motion)

• Focuses on position,speed, velocity and acceleration of bodies

• Speed: Rate of change of positionwith time (scalar)

• Velocity: Rate of change of positionwith time (vector)

• Acceleration: Rate of change of velocity with time (vector)


Kinetics• Study of the motion of bodies with regard to the mass and forces acting on them

(considering the forces that cause the motion)

• Focuses on mass and forces acting on bodies

•Mass: Amountof matter contained in a body (scalar)

• Force: Thatchanges or tends to change the state of rest or motion of a body (vector)


Kinetics(NewtonLaws)• A body will remain at rest or continue to move in a straight line at a constant speed

unless acted uponby a force

• The acceleration of a body is proportional to the resultant force acting on the body and

is in the same direction as the resultant force

• For every action, there is an equal and opposite reaction


RigidBodyandSoftBody


RigidBody• A systemof particles that remain at fixed distances fromone another

• Distance between any two points of a rigid body remains constant in time regardless of

external forces exerted on it

• Rigid body translates or rotates as a whole, no relative translation or rotation among

the particles of a rigid body

• It does not change its shapeduring its motion or when it encounters any collision


SoftBody• A systemof particles that can change their distances fromone another

• Distance between any two points of a soft body changes with respect to the external

forces exerted on it

• There is relative translation or rotation among the particles of a soft body

• It can change its shapeduring its motion or when it encounters any collision


CollisionDetectionandCollisionResponse


CollisionDetection• Process of determiningwhether two or morebodies have run into each other or not

• Computational geometry problem involving the calculation of whether and where two

or more bodies have collided or they are about to collide

• Discrete Collision: Determinewhether bodies are colliding at current time or not

• ContinuousCollision: Predict the exact point and time of collision between bodies


CollisionDetection


Nocollisionatcurrenttime

Collisionatcurrenttime

NocollisionatcurrenttimeUpcomingcollisioninfuture

Collisionatcurrenttime

DiscreteCollisionDetection Continuous CollisionDetection

CollisionResponse• How bodieswill react to collision

• Simulate what happenswhen a collision is detected between bodies

•Motion and shape of bodies after they have collided with respect to their properties

• Rigid Body Collision: Bodies can change their position and rotation but not shapes

• Soft Body Collision: Bodies can change their position, rotation and shapes


Reference• PhysicsforGameDevelopers- DavidMBourg,BryanBywalec


5-physics in game (game development - umt spring 2017)

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