Physics_RigidBody.cpp

Go to the documentation of this file.

/*
===========================================================================

Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company. 

This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).  

Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Doom 3 Source Code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Doom 3 Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

===========================================================================
*/

#include "../../idlib/precompiled.h"
#pragma hdrstop

#include "../Game_local.h"

CLASS_DECLARATION( idPhysics_Base, idPhysics_RigidBody )
END_CLASS

const float STOP_SPEED          = 10.0f;


#undef RB_TIMINGS

#ifdef RB_TIMINGS
static int lastTimerReset = 0;
static int numRigidBodies = 0;
static idTimer timer_total, timer_collision;
#endif


/*
================
RigidBodyDerivatives
================
*/
void RigidBodyDerivatives( const float t, const void *clientData, const float *state, float *derivatives ) {
        const idPhysics_RigidBody *p = (idPhysics_RigidBody *) clientData;
        rigidBodyIState_t *s = (rigidBodyIState_t *) state;
        // NOTE: this struct should be build conform rigidBodyIState_t
        struct rigidBodyDerivatives_s {
                idVec3                          linearVelocity;
                idMat3                          angularMatrix;
                idVec3                          force;
                idVec3                          torque;
        } *d = (struct rigidBodyDerivatives_s *) derivatives;
        idVec3 angularVelocity;
        idMat3 inverseWorldInertiaTensor;

        inverseWorldInertiaTensor = s->orientation * p->inverseInertiaTensor * s->orientation.Transpose();
        angularVelocity = inverseWorldInertiaTensor * s->angularMomentum;
        // derivatives
        d->linearVelocity = p->inverseMass * s->linearMomentum;
        d->angularMatrix = SkewSymmetric( angularVelocity ) * s->orientation;
        d->force = - p->linearFriction * s->linearMomentum + p->current.externalForce;
        d->torque = - p->angularFriction * s->angularMomentum + p->current.externalTorque;
}

/*
================
idPhysics_RigidBody::Integrate

  Calculate next state from the current state using an integrator.
================
*/
void idPhysics_RigidBody::Integrate( float deltaTime, rigidBodyPState_t &next ) {
        idVec3 position;

        position = current.i.position;
        current.i.position += centerOfMass * current.i.orientation;

        current.i.orientation.TransposeSelf();

        integrator->Evaluate( (float *) &current.i, (float *) &next.i, 0, deltaTime );
        next.i.orientation.OrthoNormalizeSelf();

        // apply gravity
        next.i.linearMomentum += deltaTime * gravityVector * mass;

        current.i.orientation.TransposeSelf();
        next.i.orientation.TransposeSelf();

        current.i.position = position;
        next.i.position -= centerOfMass * next.i.orientation;

        next.atRest = current.atRest;
}

/*
================
idPhysics_RigidBody::CollisionImpulse

  Calculates the collision impulse using the velocity relative to the collision object.
  The current state should be set to the moment of impact.
================
*/
bool idPhysics_RigidBody::CollisionImpulse( const trace_t &collision, idVec3 &impulse ) {
        idVec3 r, linearVelocity, angularVelocity, velocity;
        idMat3 inverseWorldInertiaTensor;
        float impulseNumerator, impulseDenominator, vel;
        impactInfo_t info;
        idEntity *ent;

        // get info from other entity involved
        ent = gameLocal.entities[collision.c.entityNum];
        ent->GetImpactInfo( self, collision.c.id, collision.c.point, &info );

        // collision point relative to the body center of mass
        r = collision.c.point - ( current.i.position + centerOfMass * current.i.orientation );
        // the velocity at the collision point
        linearVelocity = inverseMass * current.i.linearMomentum;
        inverseWorldInertiaTensor = current.i.orientation.Transpose() * inverseInertiaTensor * current.i.orientation;
        angularVelocity = inverseWorldInertiaTensor * current.i.angularMomentum;
        velocity = linearVelocity + angularVelocity.Cross(r);
        // subtract velocity of other entity
        velocity -= info.velocity;

        // velocity in normal direction
        vel = velocity * collision.c.normal;

        if ( vel > -STOP_SPEED ) {
                impulseNumerator = STOP_SPEED;
        }
        else {
                impulseNumerator = -( 1.0f + bouncyness ) * vel;
        }
        impulseDenominator = inverseMass + ( ( inverseWorldInertiaTensor * r.Cross( collision.c.normal ) ).Cross( r ) * collision.c.normal );
        if ( info.invMass ) {
                impulseDenominator += info.invMass + ( ( info.invInertiaTensor * info.position.Cross( collision.c.normal ) ).Cross( info.position ) * collision.c.normal );
        }
        impulse = (impulseNumerator / impulseDenominator) * collision.c.normal;

        // update linear and angular momentum with impulse
        current.i.linearMomentum += impulse;
        current.i.angularMomentum += r.Cross(impulse);

        // if no movement at all don't blow up
        if ( collision.fraction < 0.0001f ) {
                current.i.linearMomentum *= 0.5f;
                current.i.angularMomentum *= 0.5f;
        }

        // callback to self to let the entity know about the collision
        return self->Collide( collision, velocity );
}

/*
================
idPhysics_RigidBody::CheckForCollisions

  Check for collisions between the current and next state.
  If there is a collision the next state is set to the state at the moment of impact.
================
*/
bool idPhysics_RigidBody::CheckForCollisions( const float deltaTime, rigidBodyPState_t &next, trace_t &collision ) {
//#define TEST_COLLISION_DETECTION
        idMat3 axis;
        idRotation rotation;
        bool collided = false;

#ifdef TEST_COLLISION_DETECTION
        bool startsolid;
        if ( gameLocal.clip.Contents( current.i.position, clipModel, current.i.orientation, clipMask, self ) ) {
                startsolid = true;
        }
#endif

        TransposeMultiply( current.i.orientation, next.i.orientation, axis );
        rotation = axis.ToRotation();
        rotation.SetOrigin( current.i.position );

        // if there was a collision
        if ( gameLocal.clip.Motion( collision, current.i.position, next.i.position, rotation, clipModel, current.i.orientation, clipMask, self ) ) {
                // set the next state to the state at the moment of impact
                next.i.position = collision.endpos;
                next.i.orientation = collision.endAxis;
                next.i.linearMomentum = current.i.linearMomentum;
                next.i.angularMomentum = current.i.angularMomentum;
                collided = true;
        }

#ifdef TEST_COLLISION_DETECTION
        if ( gameLocal.clip.Contents( next.i.position, clipModel, next.i.orientation, clipMask, self ) ) {
                if ( !startsolid ) {
                        int bah = 1;
                }
        }
#endif
        return collided;
}

/*
================
idPhysics_RigidBody::ContactFriction

  Does not solve friction for multiple simultaneous contacts but applies contact friction in isolation.
  Uses absolute velocity at the contact points instead of the velocity relative to the contact object.
================
*/
void idPhysics_RigidBody::ContactFriction( float deltaTime ) {
        int i;
        float magnitude, impulseNumerator, impulseDenominator;
        idMat3 inverseWorldInertiaTensor;
        idVec3 linearVelocity, angularVelocity;
        idVec3 massCenter, r, velocity, normal, impulse, normalVelocity;

        inverseWorldInertiaTensor = current.i.orientation.Transpose() * inverseInertiaTensor * current.i.orientation;

        massCenter = current.i.position + centerOfMass * current.i.orientation;

        for ( i = 0; i < contacts.Num(); i++ ) {

                r = contacts[i].point - massCenter;

                // calculate velocity at contact point
                linearVelocity = inverseMass * current.i.linearMomentum;
                angularVelocity = inverseWorldInertiaTensor * current.i.angularMomentum;
                velocity = linearVelocity + angularVelocity.Cross(r);

                // velocity along normal vector
                normalVelocity = ( velocity * contacts[i].normal ) * contacts[i].normal;

                // calculate friction impulse
                normal = -( velocity - normalVelocity );
                magnitude = normal.Normalize();
                impulseNumerator = contactFriction * magnitude;
                impulseDenominator = inverseMass + ( ( inverseWorldInertiaTensor * r.Cross( normal ) ).Cross( r ) * normal );
                impulse = (impulseNumerator / impulseDenominator) * normal;

                // apply friction impulse
                current.i.linearMomentum += impulse;
                current.i.angularMomentum += r.Cross(impulse);

                // if moving towards the surface at the contact point
                if ( normalVelocity * contacts[i].normal < 0.0f ) {
                        // calculate impulse
                        normal = -normalVelocity;
                        impulseNumerator = normal.Normalize();
                        impulseDenominator = inverseMass + ( ( inverseWorldInertiaTensor * r.Cross( normal ) ).Cross( r ) * normal );
                        impulse = (impulseNumerator / impulseDenominator) * normal;

                        // apply impulse
                        current.i.linearMomentum += impulse;
                        current.i.angularMomentum += r.Cross( impulse );
                }
        }
}

/*
================
idPhysics_RigidBody::TestIfAtRest

  Returns true if the body is considered at rest.
  Does not catch all cases where the body is at rest but is generally good enough.
================
*/
bool idPhysics_RigidBody::TestIfAtRest( void ) const {
        int i;
        float gv;
        idVec3 v, av, normal, point;
        idMat3 inverseWorldInertiaTensor;
        idFixedWinding contactWinding;

        if ( current.atRest >= 0 ) {
                return true;
        }

        // need at least 3 contact points to come to rest
        if ( contacts.Num() < 3 ) {
                return false;
        }

        // get average contact plane normal
        normal.Zero();
        for ( i = 0; i < contacts.Num(); i++ ) {
                normal += contacts[i].normal;
        }
        normal /= (float) contacts.Num();
        normal.Normalize();

        // if on a too steep surface
        if ( (normal * gravityNormal) > -0.7f ) {
                return false;
        }

        // create bounds for contact points
        contactWinding.Clear();
        for ( i = 0; i < contacts.Num(); i++ ) {
                // project point onto plane through origin orthogonal to the gravity
                point = contacts[i].point - (contacts[i].point * gravityNormal) * gravityNormal;
                contactWinding.AddToConvexHull( point, gravityNormal );
        }

        // need at least 3 contact points to come to rest
        if ( contactWinding.GetNumPoints() < 3 ) {
                return false;
        }

        // center of mass in world space
        point = current.i.position + centerOfMass * current.i.orientation;
        point -= (point * gravityNormal) * gravityNormal;

        // if the point is not inside the winding
        if ( !contactWinding.PointInside( gravityNormal, point, 0 ) ) {
                return false;
        }

        // linear velocity of body
        v = inverseMass * current.i.linearMomentum;
        // linear velocity in gravity direction
        gv = v * gravityNormal;
        // linear velocity orthogonal to gravity direction
        v -= gv * gravityNormal;

        // if too much velocity orthogonal to gravity direction
        if ( v.Length() > STOP_SPEED ) {
                return false;
        }
        // if too much velocity in gravity direction
        if ( gv > 2.0f * STOP_SPEED || gv < -2.0f * STOP_SPEED ) {
                return false;
        }

        // calculate rotational velocity
        inverseWorldInertiaTensor = current.i.orientation * inverseInertiaTensor * current.i.orientation.Transpose();
        av = inverseWorldInertiaTensor * current.i.angularMomentum;

        // if too much rotational velocity
        if ( av.LengthSqr() > STOP_SPEED ) {
                return false;
        }

        return true;
}

/*
================
idPhysics_RigidBody::DropToFloorAndRest

  Drops the object straight down to the floor and verifies if the object is at rest on the floor.
================
*/
void idPhysics_RigidBody::DropToFloorAndRest( void ) {
        idVec3 down;
        trace_t tr;

        if ( testSolid ) {

                testSolid = false;

                if ( gameLocal.clip.Contents( current.i.position, clipModel, current.i.orientation, clipMask, self ) ) {
                        gameLocal.DWarning( "rigid body in solid for entity '%s' type '%s' at (%s)",
                                                                self->name.c_str(), self->GetType()->classname, current.i.position.ToString(0) );
                        Rest();
                        dropToFloor = false;
                        return;
                }
        }

        // put the body on the floor
        down = current.i.position + gravityNormal * 128.0f;
        gameLocal.clip.Translation( tr, current.i.position, down, clipModel, current.i.orientation, clipMask, self );
        current.i.position = tr.endpos;
        clipModel->Link( gameLocal.clip, self, clipModel->GetId(), tr.endpos, current.i.orientation );

        // if on the floor already
        if ( tr.fraction == 0.0f ) {
                // test if we are really at rest
                EvaluateContacts();
                if ( !TestIfAtRest() ) {
                        gameLocal.DWarning( "rigid body not at rest for entity '%s' type '%s' at (%s)",
                                                                self->name.c_str(), self->GetType()->classname, current.i.position.ToString(0) );
                }
                Rest();
                dropToFloor = false;
        } else if ( IsOutsideWorld() ) {
                gameLocal.Warning( "rigid body outside world bounds for entity '%s' type '%s' at (%s)",
                                                        self->name.c_str(), self->GetType()->classname, current.i.position.ToString(0) );
                Rest();
                dropToFloor = false;
        }
}

/*
================
idPhysics_RigidBody::DebugDraw
================
*/
void idPhysics_RigidBody::DebugDraw( void ) {

        if ( rb_showBodies.GetBool() || ( rb_showActive.GetBool() && current.atRest < 0 ) ) {
                collisionModelManager->DrawModel( clipModel->Handle(), clipModel->GetOrigin(), clipModel->GetAxis(), vec3_origin, 0.0f );
        }

        if ( rb_showMass.GetBool() ) {
                gameRenderWorld->DrawText( va( "\n%1.2f", mass ), current.i.position, 0.08f, colorCyan, gameLocal.GetLocalPlayer()->viewAngles.ToMat3(), 1 );
        }

        if ( rb_showInertia.GetBool() ) {
                idMat3 &I = inertiaTensor;
                gameRenderWorld->DrawText( va( "\n\n\n( %.1f %.1f %.1f )\n( %.1f %.1f %.1f )\n( %.1f %.1f %.1f )",
                                                                        I[0].x, I[0].y, I[0].z,
                                                                        I[1].x, I[1].y, I[1].z,
                                                                        I[2].x, I[2].y, I[2].z ),
                                                                        current.i.position, 0.05f, colorCyan, gameLocal.GetLocalPlayer()->viewAngles.ToMat3(), 1 );
        }

        if ( rb_showVelocity.GetBool() ) {
                DrawVelocity( clipModel->GetId(), 0.1f, 4.0f );
        }
}

/*
================
idPhysics_RigidBody::idPhysics_RigidBody
================
*/
idPhysics_RigidBody::idPhysics_RigidBody( void ) {

        // set default rigid body properties
        SetClipMask( MASK_SOLID );
        SetBouncyness( 0.6f );
        SetFriction( 0.6f, 0.6f, 0.0f );
        clipModel = NULL;

        memset( &current, 0, sizeof( current ) );

        current.atRest = -1;
        current.lastTimeStep = USERCMD_MSEC;

        current.i.position.Zero();
        current.i.orientation.Identity();

        current.i.linearMomentum.Zero();
        current.i.angularMomentum.Zero();

        saved = current;

        mass = 1.0f;
        inverseMass = 1.0f;
        centerOfMass.Zero();
        inertiaTensor.Identity();
        inverseInertiaTensor.Identity();

        // use the least expensive euler integrator
        integrator = new idODE_Euler( sizeof(rigidBodyIState_t) / sizeof(float), RigidBodyDerivatives, this );

        dropToFloor = false;
        noImpact = false;
        noContact = false;

        hasMaster = false;
        isOrientated = false;

#ifdef RB_TIMINGS
        lastTimerReset = 0;
#endif
}

/*
================
idPhysics_RigidBody::~idPhysics_RigidBody
================
*/
idPhysics_RigidBody::~idPhysics_RigidBody( void ) {
        if ( clipModel ) {
                delete clipModel;
                clipModel = NULL;
        }
        delete integrator;
}

/*
================
idPhysics_RigidBody_SavePState
================
*/
void idPhysics_RigidBody_SavePState( idSaveGame *savefile, const rigidBodyPState_t &state ) {
        savefile->WriteInt( state.atRest );
        savefile->WriteFloat( state.lastTimeStep );
        savefile->WriteVec3( state.localOrigin );
        savefile->WriteMat3( state.localAxis );
        savefile->WriteVec6( state.pushVelocity );
        savefile->WriteVec3( state.externalForce );
        savefile->WriteVec3( state.externalTorque );

        savefile->WriteVec3( state.i.position );
        savefile->WriteMat3( state.i.orientation );
        savefile->WriteVec3( state.i.linearMomentum );
        savefile->WriteVec3( state.i.angularMomentum );
}

/*
================
idPhysics_RigidBody_RestorePState
================
*/
void idPhysics_RigidBody_RestorePState( idRestoreGame *savefile, rigidBodyPState_t &state ) {
        savefile->ReadInt( state.atRest );
        savefile->ReadFloat( state.lastTimeStep );
        savefile->ReadVec3( state.localOrigin );
        savefile->ReadMat3( state.localAxis );
        savefile->ReadVec6( state.pushVelocity );
        savefile->ReadVec3( state.externalForce );
        savefile->ReadVec3( state.externalTorque );

        savefile->ReadVec3( state.i.position );
        savefile->ReadMat3( state.i.orientation );
        savefile->ReadVec3( state.i.linearMomentum );
        savefile->ReadVec3( state.i.angularMomentum );
}

/*
================
idPhysics_RigidBody::Save
================
*/
void idPhysics_RigidBody::Save( idSaveGame *savefile ) const {

        idPhysics_RigidBody_SavePState( savefile, current );
        idPhysics_RigidBody_SavePState( savefile, saved );

        savefile->WriteFloat( linearFriction );
        savefile->WriteFloat( angularFriction );
        savefile->WriteFloat( contactFriction );
        savefile->WriteFloat( bouncyness );
        savefile->WriteClipModel( clipModel );

        savefile->WriteFloat( mass );
        savefile->WriteFloat( inverseMass );
        savefile->WriteVec3( centerOfMass );
        savefile->WriteMat3( inertiaTensor );
        savefile->WriteMat3( inverseInertiaTensor );

        savefile->WriteBool( dropToFloor );
        savefile->WriteBool( testSolid );
        savefile->WriteBool( noImpact );
        savefile->WriteBool( noContact );

        savefile->WriteBool( hasMaster );
        savefile->WriteBool( isOrientated );
}

/*
================
idPhysics_RigidBody::Restore
================
*/
void idPhysics_RigidBody::Restore( idRestoreGame *savefile ) {

        idPhysics_RigidBody_RestorePState( savefile, current );
        idPhysics_RigidBody_RestorePState( savefile, saved );

        savefile->ReadFloat( linearFriction );
        savefile->ReadFloat( angularFriction );
        savefile->ReadFloat( contactFriction );
        savefile->ReadFloat( bouncyness );
        savefile->ReadClipModel( clipModel );

        savefile->ReadFloat( mass );
        savefile->ReadFloat( inverseMass );
        savefile->ReadVec3( centerOfMass );
        savefile->ReadMat3( inertiaTensor );
        savefile->ReadMat3( inverseInertiaTensor );

        savefile->ReadBool( dropToFloor );
        savefile->ReadBool( testSolid );
        savefile->ReadBool( noImpact );
        savefile->ReadBool( noContact );

        savefile->ReadBool( hasMaster );
        savefile->ReadBool( isOrientated );
}

/*
================
idPhysics_RigidBody::SetClipModel
================
*/
#define MAX_INERTIA_SCALE               10.0f

void idPhysics_RigidBody::SetClipModel( idClipModel *model, const float density, int id, bool freeOld ) {
        int minIndex;
        idMat3 inertiaScale;

        assert( self );
        assert( model );                                        // we need a clip model
        assert( model->IsTraceModel() );        // and it should be a trace model
        assert( density > 0.0f );                       // density should be valid

        if ( clipModel && clipModel != model && freeOld ) {
                delete clipModel;
        }
        clipModel = model;
        clipModel->Link( gameLocal.clip, self, 0, current.i.position, current.i.orientation );

        // get mass properties from the trace model
        clipModel->GetMassProperties( density, mass, centerOfMass, inertiaTensor );

        // check whether or not the clip model has valid mass properties
        if ( mass <= 0.0f || FLOAT_IS_NAN( mass ) ) {
                gameLocal.Warning( "idPhysics_RigidBody::SetClipModel: invalid mass for entity '%s' type '%s'",
                                                        self->name.c_str(), self->GetType()->classname );
                mass = 1.0f;
                centerOfMass.Zero();
                inertiaTensor.Identity();
        }

        // check whether or not the inertia tensor is balanced
        minIndex = Min3Index( inertiaTensor[0][0], inertiaTensor[1][1], inertiaTensor[2][2] );
        inertiaScale.Identity();
        inertiaScale[0][0] = inertiaTensor[0][0] / inertiaTensor[minIndex][minIndex];
        inertiaScale[1][1] = inertiaTensor[1][1] / inertiaTensor[minIndex][minIndex];
        inertiaScale[2][2] = inertiaTensor[2][2] / inertiaTensor[minIndex][minIndex];

        if ( inertiaScale[0][0] > MAX_INERTIA_SCALE || inertiaScale[1][1] > MAX_INERTIA_SCALE || inertiaScale[2][2] > MAX_INERTIA_SCALE ) {
                gameLocal.DWarning( "idPhysics_RigidBody::SetClipModel: unbalanced inertia tensor for entity '%s' type '%s'",
                                                        self->name.c_str(), self->GetType()->classname );
                float min = inertiaTensor[minIndex][minIndex] * MAX_INERTIA_SCALE;
                inertiaScale[(minIndex+1)%3][(minIndex+1)%3] = min / inertiaTensor[(minIndex+1)%3][(minIndex+1)%3];
                inertiaScale[(minIndex+2)%3][(minIndex+2)%3] = min / inertiaTensor[(minIndex+2)%3][(minIndex+2)%3];
                inertiaTensor *= inertiaScale;
        }

        inverseMass = 1.0f / mass;
        inverseInertiaTensor = inertiaTensor.Inverse() * ( 1.0f / 6.0f );

        current.i.linearMomentum.Zero();
        current.i.angularMomentum.Zero();
}

/*
================
idPhysics_RigidBody::GetClipModel
================
*/
idClipModel *idPhysics_RigidBody::GetClipModel( int id ) const {
        return clipModel;
}

/*
================
idPhysics_RigidBody::GetNumClipModels
================
*/
int idPhysics_RigidBody::GetNumClipModels( void ) const {
        return 1;
}

/*
================
idPhysics_RigidBody::SetMass
================
*/
void idPhysics_RigidBody::SetMass( float mass, int id ) {
        assert( mass > 0.0f );
        inertiaTensor *= mass / this->mass;
        inverseInertiaTensor = inertiaTensor.Inverse() * (1.0f / 6.0f);
        this->mass = mass;
        inverseMass = 1.0f / mass;
}

/*
================
idPhysics_RigidBody::GetMass
================
*/
float idPhysics_RigidBody::GetMass( int id ) const {
        return mass;
}

/*
================
idPhysics_RigidBody::SetFriction
================
*/
void idPhysics_RigidBody::SetFriction( const float linear, const float angular, const float contact ) {
        if (    linear < 0.0f || linear > 1.0f ||
                        angular < 0.0f || angular > 1.0f ||
                        contact < 0.0f || contact > 1.0f ) {
                return;
        }
        linearFriction = linear;
        angularFriction = angular;
        contactFriction = contact;
}

/*
================
idPhysics_RigidBody::SetBouncyness
================
*/
void idPhysics_RigidBody::SetBouncyness( const float b ) {
        if ( b < 0.0f || b > 1.0f ) {
                return;
        }
        bouncyness = b;
}

/*
================
idPhysics_RigidBody::Rest
================
*/
void idPhysics_RigidBody::Rest( void ) {
        current.atRest = gameLocal.time;
        current.i.linearMomentum.Zero();
        current.i.angularMomentum.Zero();
        self->BecomeInactive( TH_PHYSICS );
}

/*
================
idPhysics_RigidBody::DropToFloor
================
*/
void idPhysics_RigidBody::DropToFloor( void ) {
        dropToFloor = true;
        testSolid = true;
}

/*
================
idPhysics_RigidBody::NoContact
================
*/
void idPhysics_RigidBody::NoContact( void ) {
        noContact = true;
}

/*
================
idPhysics_RigidBody::Activate
================
*/
void idPhysics_RigidBody::Activate( void ) {
        current.atRest = -1;
        self->BecomeActive( TH_PHYSICS );
}

/*
================
idPhysics_RigidBody::PutToRest

  put to rest untill something collides with this physics object
================
*/
void idPhysics_RigidBody::PutToRest( void ) {
        Rest();
}

/*
================
idPhysics_RigidBody::EnableImpact
================
*/
void idPhysics_RigidBody::EnableImpact( void ) {
        noImpact = false;
}

/*
================
idPhysics_RigidBody::DisableImpact
================
*/
void idPhysics_RigidBody::DisableImpact( void ) {
        noImpact = true;
}

/*
================
idPhysics_RigidBody::SetContents
================
*/
void idPhysics_RigidBody::SetContents( int contents, int id ) {
        clipModel->SetContents( contents );
}

/*
================
idPhysics_RigidBody::GetContents
================
*/
int idPhysics_RigidBody::GetContents( int id ) const {
        return clipModel->GetContents();
}

/*
================
idPhysics_RigidBody::GetBounds
================
*/
const idBounds &idPhysics_RigidBody::GetBounds( int id ) const {
        return clipModel->GetBounds();
}

/*
================
idPhysics_RigidBody::GetAbsBounds
================
*/
const idBounds &idPhysics_RigidBody::GetAbsBounds( int id ) const {
        return clipModel->GetAbsBounds();
}

/*
================
idPhysics_RigidBody::Evaluate

  Evaluate the impulse based rigid body physics.
  When a collision occurs an impulse is applied at the moment of impact but
  the remaining time after the collision is ignored.
================
*/
bool idPhysics_RigidBody::Evaluate( int timeStepMSec, int endTimeMSec ) {
        rigidBodyPState_t next;
        idAngles angles;
        trace_t collision;
        idVec3 impulse;
        idEntity *ent;
        idVec3 oldOrigin, masterOrigin;
        idMat3 oldAxis, masterAxis;
        float timeStep;
        bool collided, cameToRest = false;

        timeStep = MS2SEC( timeStepMSec );
        current.lastTimeStep = timeStep;

        if ( hasMaster ) {
                oldOrigin = current.i.position;
                oldAxis = current.i.orientation;
                self->GetMasterPosition( masterOrigin, masterAxis );
                current.i.position = masterOrigin + current.localOrigin * masterAxis;
                if ( isOrientated ) {
                        current.i.orientation = current.localAxis * masterAxis;
                }
                else {
                        current.i.orientation = current.localAxis;
                }
                clipModel->Link( gameLocal.clip, self, clipModel->GetId(), current.i.position, current.i.orientation );
                current.i.linearMomentum = mass * ( ( current.i.position - oldOrigin ) / timeStep );
                current.i.angularMomentum = inertiaTensor * ( ( current.i.orientation * oldAxis.Transpose() ).ToAngularVelocity() / timeStep );
                current.externalForce.Zero();
                current.externalTorque.Zero();

                return ( current.i.position != oldOrigin || current.i.orientation != oldAxis );
        }

        // if the body is at rest
        if ( current.atRest >= 0 || timeStep <= 0.0f ) {
                DebugDraw();
                return false;
        }

        // if putting the body to rest
        if ( dropToFloor ) {
                DropToFloorAndRest();
                current.externalForce.Zero();
                current.externalTorque.Zero();
                return true;
        }

#ifdef RB_TIMINGS
        timer_total.Start();
#endif

        // move the rigid body velocity into the frame of a pusher
//      current.i.linearMomentum -= current.pushVelocity.SubVec3( 0 ) * mass;
//      current.i.angularMomentum -= current.pushVelocity.SubVec3( 1 ) * inertiaTensor;

        clipModel->Unlink();

        next = current;

        // calculate next position and orientation
        Integrate( timeStep, next );

#ifdef RB_TIMINGS
        timer_collision.Start();
#endif

        // check for collisions from the current to the next state
        collided = CheckForCollisions( timeStep, next, collision );

#ifdef RB_TIMINGS
        timer_collision.Stop();
#endif

        // set the new state
        current = next;

        if ( collided ) {
                // apply collision impulse
                if ( CollisionImpulse( collision, impulse ) ) {
                        current.atRest = gameLocal.time;
                }
        }

        // update the position of the clip model
        clipModel->Link( gameLocal.clip, self, clipModel->GetId(), current.i.position, current.i.orientation );

        DebugDraw();

        if ( !noContact ) {

#ifdef RB_TIMINGS
                timer_collision.Start();
#endif
                // get contacts
                EvaluateContacts();

#ifdef RB_TIMINGS
                timer_collision.Stop();
#endif

                // check if the body has come to rest
                if ( TestIfAtRest() ) {
                        // put to rest
                        Rest();
                        cameToRest = true;
                }  else {
                        // apply contact friction
                        ContactFriction( timeStep );
                }
        }

        if ( current.atRest < 0 ) {
                ActivateContactEntities();
        }

        if ( collided ) {
                // if the rigid body didn't come to rest or the other entity is not at rest
                ent = gameLocal.entities[collision.c.entityNum];
                if ( ent && ( !cameToRest || !ent->IsAtRest() ) ) {
                        // apply impact to other entity
                        ent->ApplyImpulse( self, collision.c.id, collision.c.point, -impulse );
                }
        }

        // move the rigid body velocity back into the world frame
//      current.i.linearMomentum += current.pushVelocity.SubVec3( 0 ) * mass;
//      current.i.angularMomentum += current.pushVelocity.SubVec3( 1 ) * inertiaTensor;
        current.pushVelocity.Zero();

        current.lastTimeStep = timeStep;
        current.externalForce.Zero();
        current.externalTorque.Zero();

        if ( IsOutsideWorld() ) {
                gameLocal.Warning( "rigid body moved outside world bounds for entity '%s' type '%s' at (%s)",
                                        self->name.c_str(), self->GetType()->classname, current.i.position.ToString(0) );
                Rest();
        }

#ifdef RB_TIMINGS
        timer_total.Stop();

        if ( rb_showTimings->integer == 1 ) {
                gameLocal.Printf( "%12s: t %1.4f cd %1.4f\n",
                                                self->name.c_str(),
                                                timer_total.Milliseconds(), timer_collision.Milliseconds() );
                lastTimerReset = 0;
        }
        else if ( rb_showTimings->integer == 2 ) {
                numRigidBodies++;
                if ( endTimeMSec > lastTimerReset ) {
                        gameLocal.Printf( "rb %d: t %1.4f cd %1.4f\n",
                                                        numRigidBodies,
                                                        timer_total.Milliseconds(), timer_collision.Milliseconds() );
                }
        }
        if ( endTimeMSec > lastTimerReset ) {
                lastTimerReset = endTimeMSec;
                numRigidBodies = 0;
                timer_total.Clear();
                timer_collision.Clear();
        }
#endif

        return true;
}

/*
================
idPhysics_RigidBody::UpdateTime
================
*/
void idPhysics_RigidBody::UpdateTime( int endTimeMSec ) {
}

/*
================
idPhysics_RigidBody::GetTime
================
*/
int idPhysics_RigidBody::GetTime( void ) const {
        return gameLocal.time;
}

/*
================
idPhysics_RigidBody::GetImpactInfo
================
*/
void idPhysics_RigidBody::GetImpactInfo( const int id, const idVec3 &point, impactInfo_t *info ) const {
        idVec3 linearVelocity, angularVelocity;
        idMat3 inverseWorldInertiaTensor;

        linearVelocity = inverseMass * current.i.linearMomentum;
        inverseWorldInertiaTensor = current.i.orientation.Transpose() * inverseInertiaTensor * current.i.orientation;
        angularVelocity = inverseWorldInertiaTensor * current.i.angularMomentum;

        info->invMass = inverseMass;
        info->invInertiaTensor = inverseWorldInertiaTensor;
        info->position = point - ( current.i.position + centerOfMass * current.i.orientation );
        info->velocity = linearVelocity + angularVelocity.Cross( info->position );
}

/*
================
idPhysics_RigidBody::ApplyImpulse
================
*/
void idPhysics_RigidBody::ApplyImpulse( const int id, const idVec3 &point, const idVec3 &impulse ) {
        if ( noImpact ) {
                return;
        }
        current.i.linearMomentum += impulse;
        current.i.angularMomentum += ( point - ( current.i.position + centerOfMass * current.i.orientation ) ).Cross( impulse );
        Activate();
}

/*
================
idPhysics_RigidBody::AddForce
================
*/
void idPhysics_RigidBody::AddForce( const int id, const idVec3 &point, const idVec3 &force ) {
        if ( noImpact ) {
                return;
        }
        current.externalForce += force;
        current.externalTorque += ( point - ( current.i.position + centerOfMass * current.i.orientation ) ).Cross( force );
        Activate();
}

/*
================
idPhysics_RigidBody::IsAtRest
================
*/
bool idPhysics_RigidBody::IsAtRest( void ) const {
        return current.atRest >= 0;
}

/*
================
idPhysics_RigidBody::GetRestStartTime
================
*/
int idPhysics_RigidBody::GetRestStartTime( void ) const {
        return current.atRest;
}

/*
================
idPhysics_RigidBody::IsPushable
================
*/
bool idPhysics_RigidBody::IsPushable( void ) const {
        return ( !noImpact && !hasMaster );
}

/*
================
idPhysics_RigidBody::SaveState
================
*/
void idPhysics_RigidBody::SaveState( void ) {
        saved = current;
}

/*
================
idPhysics_RigidBody::RestoreState
================
*/
void idPhysics_RigidBody::RestoreState( void ) {
        current = saved;

        clipModel->Link( gameLocal.clip, self, clipModel->GetId(), current.i.position, current.i.orientation );

        EvaluateContacts();
}

/*
================
idPhysics::SetOrigin
================
*/
void idPhysics_RigidBody::SetOrigin( const idVec3 &newOrigin, int id ) {
        idVec3 masterOrigin;
        idMat3 masterAxis;

        current.localOrigin = newOrigin;
        if ( hasMaster ) {
                self->GetMasterPosition( masterOrigin, masterAxis );
                current.i.position = masterOrigin + newOrigin * masterAxis;
        }
        else {
                current.i.position = newOrigin;
        }

        clipModel->Link( gameLocal.clip, self, clipModel->GetId(), current.i.position, clipModel->GetAxis() );

        Activate();
}

/*
================
idPhysics::SetAxis
================
*/
void idPhysics_RigidBody::SetAxis( const idMat3 &newAxis, int id ) {
        idVec3 masterOrigin;
        idMat3 masterAxis;

        current.localAxis = newAxis;
        if ( hasMaster && isOrientated ) {
                self->GetMasterPosition( masterOrigin, masterAxis );
                current.i.orientation = newAxis * masterAxis;
        }
        else {
                current.i.orientation = newAxis;
        }

        clipModel->Link( gameLocal.clip, self, clipModel->GetId(), clipModel->GetOrigin(), current.i.orientation );

        Activate();
}

/*
================
idPhysics::Move
================
*/
void idPhysics_RigidBody::Translate( const idVec3 &translation, int id ) {

        current.localOrigin += translation;
        current.i.position += translation;

        clipModel->Link( gameLocal.clip, self, clipModel->GetId(), current.i.position, clipModel->GetAxis() );

        Activate();
}

/*
================
idPhysics::Rotate
================
*/
void idPhysics_RigidBody::Rotate( const idRotation &rotation, int id ) {
        idVec3 masterOrigin;
        idMat3 masterAxis;

        current.i.orientation *= rotation.ToMat3();
        current.i.position *= rotation;

        if ( hasMaster ) {
                self->GetMasterPosition( masterOrigin, masterAxis );
                current.localAxis *= rotation.ToMat3();
                current.localOrigin = ( current.i.position - masterOrigin ) * masterAxis.Transpose();
        }
        else {
                current.localAxis = current.i.orientation;
                current.localOrigin = current.i.position;
        }

        clipModel->Link( gameLocal.clip, self, clipModel->GetId(), current.i.position, current.i.orientation );

        Activate();
}

/*
================
idPhysics_RigidBody::GetOrigin
================
*/
const idVec3 &idPhysics_RigidBody::GetOrigin( int id ) const {
        return current.i.position;
}

/*
================
idPhysics_RigidBody::GetAxis
================
*/
const idMat3 &idPhysics_RigidBody::GetAxis( int id ) const {
        return current.i.orientation;
}

/*
================
idPhysics_RigidBody::SetLinearVelocity
================
*/
void idPhysics_RigidBody::SetLinearVelocity( const idVec3 &newLinearVelocity, int id ) {
        current.i.linearMomentum = newLinearVelocity * mass;
        Activate();
}

/*
================
idPhysics_RigidBody::SetAngularVelocity
================
*/
void idPhysics_RigidBody::SetAngularVelocity( const idVec3 &newAngularVelocity, int id ) {
        current.i.angularMomentum = newAngularVelocity * inertiaTensor;
        Activate();
}

/*
================
idPhysics_RigidBody::GetLinearVelocity
================
*/
const idVec3 &idPhysics_RigidBody::GetLinearVelocity( int id ) const {
        static idVec3 curLinearVelocity;
        curLinearVelocity = current.i.linearMomentum * inverseMass;
        return curLinearVelocity;
}

/*
================
idPhysics_RigidBody::GetAngularVelocity
================
*/
const idVec3 &idPhysics_RigidBody::GetAngularVelocity( int id ) const {
        static idVec3 curAngularVelocity;
        idMat3 inverseWorldInertiaTensor;

        inverseWorldInertiaTensor = current.i.orientation.Transpose() * inverseInertiaTensor * current.i.orientation;
        curAngularVelocity = inverseWorldInertiaTensor * current.i.angularMomentum;
        return curAngularVelocity;
}

/*
================
idPhysics_RigidBody::ClipTranslation
================
*/
void idPhysics_RigidBody::ClipTranslation( trace_t &results, const idVec3 &translation, const idClipModel *model ) const {
        if ( model ) {
                gameLocal.clip.TranslationModel( results, clipModel->GetOrigin(), clipModel->GetOrigin() + translation,
                                                                                        clipModel, clipModel->GetAxis(), clipMask,
                                                                                        model->Handle(), model->GetOrigin(), model->GetAxis() );
        }
        else {
                gameLocal.clip.Translation( results, clipModel->GetOrigin(), clipModel->GetOrigin() + translation,
                                                                                        clipModel, clipModel->GetAxis(), clipMask, self );
        }
}

/*
================
idPhysics_RigidBody::ClipRotation
================
*/
void idPhysics_RigidBody::ClipRotation( trace_t &results, const idRotation &rotation, const idClipModel *model ) const {
        if ( model ) {
                gameLocal.clip.RotationModel( results, clipModel->GetOrigin(), rotation,
                                                                                        clipModel, clipModel->GetAxis(), clipMask,
                                                                                        model->Handle(), model->GetOrigin(), model->GetAxis() );
        }
        else {
                gameLocal.clip.Rotation( results, clipModel->GetOrigin(), rotation,
                                                                                        clipModel, clipModel->GetAxis(), clipMask, self );
        }
}

/*
================
idPhysics_RigidBody::ClipContents
================
*/
int idPhysics_RigidBody::ClipContents( const idClipModel *model ) const {
        if ( model ) {
                return gameLocal.clip.ContentsModel( clipModel->GetOrigin(), clipModel, clipModel->GetAxis(), -1,
                                                                        model->Handle(), model->GetOrigin(), model->GetAxis() );
        }
        else {
                return gameLocal.clip.Contents( clipModel->GetOrigin(), clipModel, clipModel->GetAxis(), -1, NULL );
        }
}

/*
================
idPhysics_RigidBody::DisableClip
================
*/
void idPhysics_RigidBody::DisableClip( void ) {
        clipModel->Disable();
}

/*
================
idPhysics_RigidBody::EnableClip
================
*/
void idPhysics_RigidBody::EnableClip( void ) {
        clipModel->Enable();
}

/*
================
idPhysics_RigidBody::UnlinkClip
================
*/
void idPhysics_RigidBody::UnlinkClip( void ) {
        clipModel->Unlink();
}

/*
================
idPhysics_RigidBody::LinkClip
================
*/
void idPhysics_RigidBody::LinkClip( void ) {
        clipModel->Link( gameLocal.clip, self, clipModel->GetId(), current.i.position, current.i.orientation );
}

/*
================
idPhysics_RigidBody::EvaluateContacts
================
*/
bool idPhysics_RigidBody::EvaluateContacts( void ) {
        idVec6 dir;
        int num;

        ClearContacts();

        contacts.SetNum( 10, false );

        dir.SubVec3(0) = current.i.linearMomentum + current.lastTimeStep * gravityVector * mass;
        dir.SubVec3(1) = current.i.angularMomentum;
        dir.SubVec3(0).Normalize();
        dir.SubVec3(1).Normalize();
        num = gameLocal.clip.Contacts( &contacts[0], 10, clipModel->GetOrigin(),
                                        dir, CONTACT_EPSILON, clipModel, clipModel->GetAxis(), clipMask, self );
        contacts.SetNum( num, false );

        AddContactEntitiesForContacts();

        return ( contacts.Num() != 0 );
}

/*
================
idPhysics_RigidBody::SetPushed
================
*/
void idPhysics_RigidBody::SetPushed( int deltaTime ) {
        idRotation rotation;

        rotation = ( saved.i.orientation * current.i.orientation ).ToRotation();

        // velocity with which the af is pushed
        current.pushVelocity.SubVec3(0) += ( current.i.position - saved.i.position ) / ( deltaTime * idMath::M_MS2SEC );
        current.pushVelocity.SubVec3(1) += rotation.GetVec() * -DEG2RAD( rotation.GetAngle() ) / ( deltaTime * idMath::M_MS2SEC );
}

/*
================
idPhysics_RigidBody::GetPushedLinearVelocity
================
*/
const idVec3 &idPhysics_RigidBody::GetPushedLinearVelocity( const int id ) const {
        return current.pushVelocity.SubVec3(0);
}

/*
================
idPhysics_RigidBody::GetPushedAngularVelocity
================
*/
const idVec3 &idPhysics_RigidBody::GetPushedAngularVelocity( const int id ) const {
        return current.pushVelocity.SubVec3(1);
}

/*
================
idPhysics_RigidBody::SetMaster
================
*/
void idPhysics_RigidBody::SetMaster( idEntity *master, const bool orientated ) {
        idVec3 masterOrigin;
        idMat3 masterAxis;

        if ( master ) {
                if ( !hasMaster ) {
                        // transform from world space to master space
                        self->GetMasterPosition( masterOrigin, masterAxis );
                        current.localOrigin = ( current.i.position - masterOrigin ) * masterAxis.Transpose();
                        if ( orientated ) {
                                current.localAxis = current.i.orientation * masterAxis.Transpose();
                        }
                        else {
                                current.localAxis = current.i.orientation;
                        }
                        hasMaster = true;
                        isOrientated = orientated;
                        ClearContacts();
                }
        }
        else {
                if ( hasMaster ) {
                        hasMaster = false;
                        Activate();
                }
        }
}

const float     RB_VELOCITY_MAX                         = 16000;
const int       RB_VELOCITY_TOTAL_BITS          = 16;
const int       RB_VELOCITY_EXPONENT_BITS       = idMath::BitsForInteger( idMath::BitsForFloat( RB_VELOCITY_MAX ) ) + 1;
const int       RB_VELOCITY_MANTISSA_BITS       = RB_VELOCITY_TOTAL_BITS - 1 - RB_VELOCITY_EXPONENT_BITS;
const float     RB_MOMENTUM_MAX                         = 1e20f;
const int       RB_MOMENTUM_TOTAL_BITS          = 16;
const int       RB_MOMENTUM_EXPONENT_BITS       = idMath::BitsForInteger( idMath::BitsForFloat( RB_MOMENTUM_MAX ) ) + 1;
const int       RB_MOMENTUM_MANTISSA_BITS       = RB_MOMENTUM_TOTAL_BITS - 1 - RB_MOMENTUM_EXPONENT_BITS;
const float     RB_FORCE_MAX                            = 1e20f;
const int       RB_FORCE_TOTAL_BITS                     = 16;
const int       RB_FORCE_EXPONENT_BITS          = idMath::BitsForInteger( idMath::BitsForFloat( RB_FORCE_MAX ) ) + 1;
const int       RB_FORCE_MANTISSA_BITS          = RB_FORCE_TOTAL_BITS - 1 - RB_FORCE_EXPONENT_BITS;

/*
================
idPhysics_RigidBody::WriteToSnapshot
================
*/
void idPhysics_RigidBody::WriteToSnapshot( idBitMsgDelta &msg ) const {
        idCQuat quat, localQuat;

        quat = current.i.orientation.ToCQuat();
        localQuat = current.localAxis.ToCQuat();

        msg.WriteLong( current.atRest );
        msg.WriteFloat( current.i.position[0] );
        msg.WriteFloat( current.i.position[1] );
        msg.WriteFloat( current.i.position[2] );
        msg.WriteFloat( quat.x );
        msg.WriteFloat( quat.y );
        msg.WriteFloat( quat.z );
        msg.WriteFloat( current.i.linearMomentum[0], RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        msg.WriteFloat( current.i.linearMomentum[1], RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        msg.WriteFloat( current.i.linearMomentum[2], RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        msg.WriteFloat( current.i.angularMomentum[0], RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        msg.WriteFloat( current.i.angularMomentum[1], RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        msg.WriteFloat( current.i.angularMomentum[2], RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        msg.WriteDeltaFloat( current.i.position[0], current.localOrigin[0] );
        msg.WriteDeltaFloat( current.i.position[1], current.localOrigin[1] );
        msg.WriteDeltaFloat( current.i.position[2], current.localOrigin[2] );
        msg.WriteDeltaFloat( quat.x, localQuat.x );
        msg.WriteDeltaFloat( quat.y, localQuat.y );
        msg.WriteDeltaFloat( quat.z, localQuat.z );
        msg.WriteDeltaFloat( 0.0f, current.pushVelocity[0], RB_VELOCITY_EXPONENT_BITS, RB_VELOCITY_MANTISSA_BITS );
        msg.WriteDeltaFloat( 0.0f, current.pushVelocity[1], RB_VELOCITY_EXPONENT_BITS, RB_VELOCITY_MANTISSA_BITS );
        msg.WriteDeltaFloat( 0.0f, current.pushVelocity[2], RB_VELOCITY_EXPONENT_BITS, RB_VELOCITY_MANTISSA_BITS );
        msg.WriteDeltaFloat( 0.0f, current.externalForce[0], RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        msg.WriteDeltaFloat( 0.0f, current.externalForce[1], RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        msg.WriteDeltaFloat( 0.0f, current.externalForce[2], RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        msg.WriteDeltaFloat( 0.0f, current.externalTorque[0], RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        msg.WriteDeltaFloat( 0.0f, current.externalTorque[1], RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        msg.WriteDeltaFloat( 0.0f, current.externalTorque[2], RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
}

/*
================
idPhysics_RigidBody::ReadFromSnapshot
================
*/
void idPhysics_RigidBody::ReadFromSnapshot( const idBitMsgDelta &msg ) {
        idCQuat quat, localQuat;

        current.atRest = msg.ReadLong();
        current.i.position[0] = msg.ReadFloat();
        current.i.position[1] = msg.ReadFloat();
        current.i.position[2] = msg.ReadFloat();
        quat.x = msg.ReadFloat();
        quat.y = msg.ReadFloat();
        quat.z = msg.ReadFloat();
        current.i.linearMomentum[0] = msg.ReadFloat( RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        current.i.linearMomentum[1] = msg.ReadFloat( RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        current.i.linearMomentum[2] = msg.ReadFloat( RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        current.i.angularMomentum[0] = msg.ReadFloat( RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        current.i.angularMomentum[1] = msg.ReadFloat( RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        current.i.angularMomentum[2] = msg.ReadFloat( RB_MOMENTUM_EXPONENT_BITS, RB_MOMENTUM_MANTISSA_BITS );
        current.localOrigin[0] = msg.ReadDeltaFloat( current.i.position[0] );
        current.localOrigin[1] = msg.ReadDeltaFloat( current.i.position[1] );
        current.localOrigin[2] = msg.ReadDeltaFloat( current.i.position[2] );
        localQuat.x = msg.ReadDeltaFloat( quat.x );
        localQuat.y = msg.ReadDeltaFloat( quat.y );
        localQuat.z = msg.ReadDeltaFloat( quat.z );
        current.pushVelocity[0] = msg.ReadDeltaFloat( 0.0f, RB_VELOCITY_EXPONENT_BITS, RB_VELOCITY_MANTISSA_BITS );
        current.pushVelocity[1] = msg.ReadDeltaFloat( 0.0f, RB_VELOCITY_EXPONENT_BITS, RB_VELOCITY_MANTISSA_BITS );
        current.pushVelocity[2] = msg.ReadDeltaFloat( 0.0f, RB_VELOCITY_EXPONENT_BITS, RB_VELOCITY_MANTISSA_BITS );
        current.externalForce[0] = msg.ReadDeltaFloat( 0.0f, RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        current.externalForce[1] = msg.ReadDeltaFloat( 0.0f, RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        current.externalForce[2] = msg.ReadDeltaFloat( 0.0f, RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        current.externalTorque[0] = msg.ReadDeltaFloat( 0.0f, RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        current.externalTorque[1] = msg.ReadDeltaFloat( 0.0f, RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );
        current.externalTorque[2] = msg.ReadDeltaFloat( 0.0f, RB_FORCE_EXPONENT_BITS, RB_FORCE_MANTISSA_BITS );

        current.i.orientation = quat.ToMat3();
        current.localAxis = localQuat.ToMat3();

        if ( clipModel ) {
                clipModel->Link( gameLocal.clip, self, clipModel->GetId(), current.i.position, current.i.orientation );
        }
}