Physics Character Controller

Physical representation of a game character

Basicshttp://cg.iit.bme.hu/gamedev/KIC/

05_PhysicsEngine/05_02_Bullet_CharacterControl_Base.zipExtractRun: CharacterControl.slnSet include and library paths (if not correct)Set working directory (if not

$(SolutionDir)/bin)CompileRun

Run

ExerciseGive the character a physical representationUse a capsule shape as a bounding objectMake the capsule dynamicDisable rotationAdd forces to move it in the sceneThe physical representation of the scene is

already loaded (static boxes)(examine the source code!!)

Play with the parameters until the movement feels natural

(Next slides show one solution)

PlayerCharacter.h#include "btBulletDynamicsCommon.h"

class PlayerCharacter{public: PlayerCharacter(Ogre::SceneManager* sm, btDiscreteDynamicsWorld*

phyW);

protected: btRigidBody* mPhysicsController;

PlayerCharacter.cppPlayerCharacter::PlayerCharacter(Ogre::SceneManager* sm, btDiscreteDynamicsWorld* phyW){

… btCollisionShape* physicsShape = new btCapsuleShape(2.0,5.0);

btDefaultMotionState* physicsMotionState = new btDefaultMotionState(btTransform(btQuaternion(0,0,0,1), btVector3(0,5,0))); btScalar mass = 1; btVector3 inertia(0,0,0); physicsShape->calculateLocalInertia(mass,inertia);

btRigidBody::btRigidBodyConstructionInfo rigidBodyCI(mass, physicsMotionState, physicsShape, inertia); mPhysicsController = new btRigidBody(rigidBodyCI);

mPhysicsController->setAngularFactor(0); //disable rotation//mPhysicsController->setDamping(0.3,0);

phyW->addRigidBody(mPhysicsController);}

PlayerCharacter.cppvoid PlayerCharacter::update(float t, float dt){

… btTransform worldTrans;

mPhysicsController->getMotionState()->getWorldTransform(worldTrans); //we don’t need rotation as it is fixed

//btQuaternion rot = worldTrans.getRotation(); //node->setOrientation(rot.w(), rot.x(), rot.y(), rot.z());

node->setPosition(worldTrans.getOrigin().x(), worldTrans.getOrigin().y()-5, worldTrans.getOrigin().z());

mPhysicsController->setLinearVelocity(btVector3(0,0,0));

}

PlayerCharacter.cppvoid PlayerCharacter::move(float amount){

if(inAction())return;

Ogre::Vector3 m = amount * getDirection() * 150;Ogre::LogManager::getSingleton().logMessage("Applying force: " + Ogre::StringConverter::toString(m));mPhysicsController->activate(true);mPhysicsController->applyImpulse(btVector3(m.x,m.y,m.z), btVector3(0,-0.5,0));

if(hasWeapon)action = PA_WEAPON_HOLD;elseaction = PA_NONE;

pose = PP_RUN;}

OgreCharacter.cppplayerCharacter = new

PlayerCharacter(sceneManager, physxHandler->getScene());

Test

More physicsConstraints/jointsRay casting (bullets, terrain, vehicle)Complex geometries

ConvexConcaveHeight field

Collision filteringSoft bodiesParticles, fluids

The End