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PostPosted: Thu Sep 23, 2010 10:25 am 
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Joined: Sat Nov 11, 2006 1:45 pm
Posts: 2
To whom it may concern, snippet for simple trigger(ghost) implementation which working with bullet character controller

1. My character controller is copy of Bullet character with minor changes.
* For triggers
* btKinematicCharacterController::recoverFromPenetration,
Code:
btBroadphasePair* collisionPair = &m_ghostObject->getOverlappingPairCache()->getOverlappingPairArray()[i];

//for trigger filtering
if (!static_cast<btCollisionObject*>(collisionPair->m_pProxy0->m_clientObject)->hasContactResponse() ||
    !static_cast<btCollisionObject*>(collisionPair->m_pProxy1->m_clientObject)->hasContactResponse())
   continue;

* btKinematicClosestNotMeConvexResultCallback::addSingleResult at the begining
Code:
         
//for trigger filtering
if (!convexResult.m_hitCollisionObject->hasContactResponse())
   return btScalar(1.0);

* for more realistic fall (you need big character gravity for good look eg. gravity=50 jump-speed=15 fall-speed=50 for (0.5, 1.125) capsule)
* btKinematicCharacterController::stepDown
instead of:
Code:
if (downVelocity < m_stepHeight)
   downVelocity = m_stepHeight;

use
Code:
if(downVelocity > m_fallSpeed)
   downVelocity = m_fallSpeed;



2. Test program

* start simulation
^Y
|
5 [rigid box 1x1x1 (5,5,0)] [actor box 1x1x1 (0,5,0)]
|
|
1 [trigger 10x1x10(0,1,0)]
0 [plane up 0,1,0] ------------------------------------------------->x

* end symulation (ghost detect rigid and actor)
^Y
|
1 [trigger 10x1x10 (0,1,0)] [rigid box 1x1x1 (5,1,0)] [actor box 1x1x1 (0,1,0)]
0 [plane up 0,1,0] ------------------------------------------------->x

SOURCES

* oije_charactercontroller.h
Code:
/**
 * Orginal licence:
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2008 Erwin Coumans  http://bulletphysics.com

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it freely,
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/

#ifndef   H_OIJE_OIJE_CHARACTERCONTROLLER
#define H_OIJE_OIJE_CHARACTERCONTROLLER

#include <LinearMath/btVector3.h>
#include <BulletDynamics/Character/btCharacterControllerInterface.h>
#include <BulletCollision/BroadphaseCollision/btCollisionAlgorithm.h>


class btCollisionShape;
class btRigidBody;
class btCollisionWorld;
class btCollisionDispatcher;
class btPairCachingGhostObject;
class btConvexShape;

namespace OiJE{
//---------------------------------------------------------------------------------------
///btKinematicCharacterController is an object that supports a sliding motion in a world.
///It uses a ghost object and convex sweep test to test for upcoming collisions. This is combined with discrete collision detection to recover from penetrations.
///Interaction between btKinematicCharacterController and dynamic rigid bodies needs to be explicity implemented by the user.
class CharacterController: public btCharacterControllerInterface
{
protected:

   btScalar m_halfHeight;
   
   btPairCachingGhostObject* m_ghostObject;
   btConvexShape*   m_convexShape;//is also in m_ghostObject, but it needs to be convex, so we store it here to avoid upcast
   
   btScalar m_verticalVelocity;
   btScalar m_verticalOffset;
   btScalar m_fallSpeed;
   btScalar m_jumpSpeed;
   btScalar m_maxJumpHeight;
   btScalar m_maxSlopeRadians; // Slope angle that is set (used for returning the exact value)
   btScalar m_maxSlopeCosine;  // Cosine equivalent of m_maxSlopeRadians (calculated once when set, for optimization)
   btScalar m_gravity;

   btScalar m_turnAngle;
   
   btScalar m_stepHeight;

   btScalar   m_addedMargin;//@todo: remove this and fix the code

   ///this is the desired walk direction, set by the user
   btVector3   m_walkDirection;
   btVector3   m_normalizedDirection;

   //some internal variables
   btVector3 m_currentPosition;
   btScalar  m_currentStepOffset;
   btVector3 m_targetPosition;

   ///keep track of the contact manifolds
   btManifoldArray   m_manifoldArray;

   bool m_touchingContact;
   btVector3 m_touchingNormal;

   bool  m_wasOnGround;
   bool  m_wasJumping;
   bool   m_useGhostObjectSweepTest;
   bool   m_useWalkDirection;
   btScalar   m_velocityTimeInterval;
   int m_upAxis;

   static btVector3* getUpAxisDirections();

   btVector3 computeReflectionDirection (const btVector3& direction, const btVector3& normal);
   btVector3 parallelComponent (const btVector3& direction, const btVector3& normal);
   btVector3 perpindicularComponent (const btVector3& direction, const btVector3& normal);

   bool recoverFromPenetration ( btCollisionWorld* collisionWorld);
   void stepUp (btCollisionWorld* collisionWorld);
   void updateTargetPositionBasedOnCollision (const btVector3& hit_normal, btScalar tangentMag = btScalar(0.0), btScalar normalMag = btScalar(1.0));
   void stepForwardAndStrafe (btCollisionWorld* collisionWorld, const btVector3& walkMove);
   void stepDown (btCollisionWorld* collisionWorld, btScalar dt);
public:
   CharacterController(btPairCachingGhostObject* ghostObject,btConvexShape* convexShape,btScalar stepHeight, int upAxis = 1);
   ~CharacterController();

   ///btActionInterface interface
   virtual void updateAction( btCollisionWorld* collisionWorld,btScalar deltaTime)
   {
      preStep ( collisionWorld);
      playerStep (collisionWorld, deltaTime);
   }
   
   ///btActionInterface interface
   void   debugDraw(btIDebugDraw* debugDrawer);

   void setUpAxis (int axis)
   {
      if (axis < 0)
         axis = 0;
      if (axis > 2)
         axis = 2;
      m_upAxis = axis;
   }

   /// This should probably be called setPositionIncrementPerSimulatorStep.
   /// This is neither a direction nor a velocity, but the amount to
   ///   increment the position each simulation iteration, regardless
   ///   of dt.
   /// This call will reset any velocity set by setVelocityForTimeInterval().
   virtual void   setWalkDirection(const btVector3& walkDirection);

   /// Caller provides a velocity with which the character should move for
   ///   the given time period.  After the time period, velocity is reset
   ///   to zero.
   /// This call will reset any walk direction set by setWalkDirection().
   /// Negative time intervals will result in no motion.
   virtual void setVelocityForTimeInterval(const btVector3& velocity,
            btScalar timeInterval);


   void setTurnAngle(btScalar ang) { m_turnAngle = ang; };

   void reset ();
   void warp (const btVector3& origin);

   void preStep (  btCollisionWorld* collisionWorld);
   void playerStep ( btCollisionWorld* collisionWorld, btScalar dt);

   void setFallSpeed (btScalar fallSpeed)            { m_fallSpeed = btFabs(fallSpeed); }
   void setJumpSpeed (btScalar jumpSpeed)            { m_jumpSpeed = btFabs(jumpSpeed); }
   void setMaxJumpHeight (btScalar maxJumpHeight)      { m_maxJumpHeight = maxJumpHeight; }
   
   ///
   bool isJumping ()const                        { return m_wasJumping; }
   ///
   bool canJump() const                        { return onGround(); }
   
   void jump ();

   void setGravity(btScalar gravity)               { m_gravity = gravity; }
   btScalar getGravity() const                     { return m_gravity; }

   /// The max slope determines the maximum angle that the controller can walk up.
   /// The slope angle is measured in radians.
   void setMaxSlope(btScalar slopeRadians)            { m_maxSlopeRadians = slopeRadians; m_maxSlopeCosine = btCos(slopeRadians); }
   btScalar getMaxSlope() const                  { return m_maxSlopeRadians; }

   btPairCachingGhostObject* getGhostObject()         { return m_ghostObject; }
   void setUseGhostSweepTest(bool use)               { m_useGhostObjectSweepTest = use; }

   bool onGround () const                        { return m_verticalVelocity == 0.0 && m_verticalOffset == 0.0; }
};
//---------------------------------------------------------------------------------------

} //namespace OiJE
#endif // H_OIJE_OIJE_CHARACTERCONTROLLER

// oije_charactercontroller.h - End of file


* oije_charactercontroller.cpp
Code:
/**
 * Orginal licence:
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2008 Erwin Coumans  http://bulletphysics.com

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it freely,
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/

#include "oije_charactercontroller.h"

#include <LinearMath/btIDebugDraw.h>
#include <BulletCollision/CollisionDispatch/btGhostObject.h>
#include <BulletCollision/CollisionShapes/btMultiSphereShape.h>
#include <BulletCollision/BroadphaseCollision/btOverlappingPairCache.h>
#include <BulletCollision/BroadphaseCollision/btCollisionAlgorithm.h>
#include <BulletCollision/CollisionDispatch/btCollisionWorld.h>
#include <LinearMath/btDefaultMotionState.h>

#include <iostream>

using namespace OiJE;

//---------------------------------------------------------------------------------------
// static helper method
static btVector3 getNormalizedVector(const btVector3& v)
{
   btVector3 n = v.normalized();
   if (n.length() < SIMD_EPSILON) {
      n.setValue(0, 0, 0);
   }
   return n;
}
//---------------------------------------------------------------------------------------
///@todo Interact with dynamic objects,
///Ride kinematicly animated platforms properly
///More realistic (or maybe just a config option) falling
/// -> Should integrate falling velocity manually and use that in stepDown()
///Support jumping
///Support ducking
class btKinematicClosestNotMeRayResultCallback : public btCollisionWorld::ClosestRayResultCallback
{
public:
   btKinematicClosestNotMeRayResultCallback (btCollisionObject* me) : btCollisionWorld::ClosestRayResultCallback(btVector3(0.0, 0.0, 0.0), btVector3(0.0, 0.0, 0.0))
   {
      m_me = me;
   }

   virtual btScalar addSingleResult(btCollisionWorld::LocalRayResult& rayResult,bool normalInWorldSpace)
   {
      if (rayResult.m_collisionObject == m_me)
         return 1.0;

      return ClosestRayResultCallback::addSingleResult (rayResult, normalInWorldSpace);
   }
protected:
   btCollisionObject* m_me;
};
//---------------------------------------------------------------------------------------
class btKinematicClosestNotMeConvexResultCallback : public btCollisionWorld::ClosestConvexResultCallback
{
public:
   btKinematicClosestNotMeConvexResultCallback (btCollisionObject* me, const btVector3& up, btScalar minSlopeDot)
   : btCollisionWorld::ClosestConvexResultCallback(btVector3(0.0, 0.0, 0.0), btVector3(0.0, 0.0, 0.0))
   , m_me(me)
   , m_up(up)
   , m_minSlopeDot(minSlopeDot)
   {
   }

   virtual btScalar addSingleResult(btCollisionWorld::LocalConvexResult& convexResult,bool normalInWorldSpace)
   {
      if (convexResult.m_hitCollisionObject == m_me)
         return btScalar(1.0);
   
      //for trigger filtering
      if (!convexResult.m_hitCollisionObject->hasContactResponse())
         return btScalar(1.0);

      btVector3 hitNormalWorld;
      if (normalInWorldSpace)
      {
         hitNormalWorld = convexResult.m_hitNormalLocal;
      } else
      {
         ///need to transform normal into worldspace
         hitNormalWorld = convexResult.m_hitCollisionObject->getWorldTransform().getBasis()*convexResult.m_hitNormalLocal;
      }

      btScalar dotUp = m_up.dot(hitNormalWorld);
      if (dotUp < m_minSlopeDot) {
         return btScalar(1.0);
      }

      return ClosestConvexResultCallback::addSingleResult (convexResult, normalInWorldSpace);
   }
protected:
   btCollisionObject* m_me;
   const btVector3 m_up;
   btScalar m_minSlopeDot;
};
//---------------------------------------------------------------------------------------
/*
 * Returns the reflection direction of a ray going 'direction' hitting a surface with normal 'normal'
 *
 * from: http://www-cs-students.stanford.edu/~adityagp/final/node3.html
 */
btVector3 CharacterController::computeReflectionDirection (const btVector3& direction, const btVector3& normal)
{
   return direction - (btScalar(2.0) * direction.dot(normal)) * normal;
}
//---------------------------------------------------------------------------------------
/*
 * Returns the portion of 'direction' that is parallel to 'normal'
 */
btVector3 CharacterController::parallelComponent (const btVector3& direction, const btVector3& normal)
{
   btScalar magnitude = direction.dot(normal);
   return normal * magnitude;
}
//---------------------------------------------------------------------------------------
/*
 * Returns the portion of 'direction' that is perpindicular to 'normal'
 */
btVector3 CharacterController::perpindicularComponent (const btVector3& direction, const btVector3& normal)
{
   return direction - parallelComponent(direction, normal);
}
//---------------------------------------------------------------------------------------
CharacterController::CharacterController (btPairCachingGhostObject* ghostObject,btConvexShape* convexShape,btScalar stepHeight, int upAxis)
{
   m_upAxis = upAxis;
   m_addedMargin = 0.02f;
   m_walkDirection.setValue(0,0,0);
   m_useGhostObjectSweepTest = true;
   m_ghostObject = ghostObject;
   m_stepHeight = stepHeight;
   m_turnAngle = btScalar(0.0);
   m_convexShape=convexShape;   
   m_useWalkDirection = true;   // use walk direction by default, legacy behavior
   m_velocityTimeInterval = 0.0;
   m_verticalVelocity = 0.0;
   m_verticalOffset = 0.0;
   m_gravity = 9.8f * 3.0f ; // 3G acceleration.
   m_fallSpeed = 55.0f; // Terminal velocity of a sky diver in m/s.
   m_jumpSpeed = 10.0f; // ?
   m_wasOnGround = false;
   m_wasJumping = false;
   setMaxSlope(btRadians(45.0f));
}
//---------------------------------------------------------------------------------------
CharacterController::~CharacterController ()
{
}
//---------------------------------------------------------------------------------------
bool CharacterController::recoverFromPenetration ( btCollisionWorld* collisionWorld)
{

   bool penetration = false;

   collisionWorld->getDispatcher()->dispatchAllCollisionPairs(m_ghostObject->getOverlappingPairCache(), collisionWorld->getDispatchInfo(), collisionWorld->getDispatcher());

   m_currentPosition = m_ghostObject->getWorldTransform().getOrigin();
   
   btScalar maxPen = btScalar(0.0);
   for (int i = 0; i < m_ghostObject->getOverlappingPairCache()->getNumOverlappingPairs(); i++)
   {
      m_manifoldArray.resize(0);

      btBroadphasePair* collisionPair = &m_ghostObject->getOverlappingPairCache()->getOverlappingPairArray()[i];

      //for trigger filtering
      if (!static_cast<btCollisionObject*>(collisionPair->m_pProxy0->m_clientObject)->hasContactResponse()
         || !static_cast<btCollisionObject*>(collisionPair->m_pProxy1->m_clientObject)->hasContactResponse())
         continue;
      
      if (collisionPair->m_algorithm)
         collisionPair->m_algorithm->getAllContactManifolds(m_manifoldArray);
      
      for (int j=0;j<m_manifoldArray.size();j++)
      {
         btPersistentManifold* manifold = m_manifoldArray[j];
         btScalar directionSign = manifold->getBody0() == m_ghostObject ? btScalar(-1.0) : btScalar(1.0);
         for (int p=0;p<manifold->getNumContacts();p++)
         {
            const btManifoldPoint&pt = manifold->getContactPoint(p);

            btScalar dist = pt.getDistance();

            if (dist < 0.0)
            {
               if (dist < maxPen)
               {
                  maxPen = dist;
                  m_touchingNormal = pt.m_normalWorldOnB * directionSign;//??

               }
               m_currentPosition += pt.m_normalWorldOnB * directionSign * dist * btScalar(0.2);
               penetration = true;
            } else {
               //printf("touching %f\n", dist);
            }
         }
         
         //manifold->clearManifold();
      }
   }
   btTransform newTrans = m_ghostObject->getWorldTransform();
   newTrans.setOrigin(m_currentPosition);
   m_ghostObject->setWorldTransform(newTrans);
//   printf("m_touchingNormal = %f,%f,%f\n",m_touchingNormal[0],m_touchingNormal[1],m_touchingNormal[2]);
   return penetration;
}
//---------------------------------------------------------------------------------------
void CharacterController::stepUp ( btCollisionWorld* world)
{
   // phase 1: up
   btTransform start, end;
   m_targetPosition = m_currentPosition + getUpAxisDirections()[m_upAxis] * (m_stepHeight + (m_verticalOffset > 0.f?m_verticalOffset:0.f));

   start.setIdentity ();
   end.setIdentity ();

   /* FIXME: Handle penetration properly */
   start.setOrigin (m_currentPosition + getUpAxisDirections()[m_upAxis] * (m_convexShape->getMargin() + m_addedMargin));
   end.setOrigin (m_targetPosition);

   btKinematicClosestNotMeConvexResultCallback callback (m_ghostObject, -getUpAxisDirections()[m_upAxis], btScalar(0.7071));
   callback.m_collisionFilterGroup = getGhostObject()->getBroadphaseHandle()->m_collisionFilterGroup;
   callback.m_collisionFilterMask = getGhostObject()->getBroadphaseHandle()->m_collisionFilterMask;
   
   if (m_useGhostObjectSweepTest)
   {
      m_ghostObject->convexSweepTest (m_convexShape, start, end, callback, world->getDispatchInfo().m_allowedCcdPenetration);
   }
   else
   {
      world->convexSweepTest (m_convexShape, start, end, callback);
   }
   
   if (callback.hasHit())
   {
      // Only modify the position if the hit was a slope and not a wall or ceiling.
      if(callback.m_hitNormalWorld.dot(getUpAxisDirections()[m_upAxis]) > 0.0)
      {
         // we moved up only a fraction of the step height
         m_currentStepOffset = m_stepHeight * callback.m_closestHitFraction;
         m_currentPosition.setInterpolate3 (m_currentPosition, m_targetPosition, callback.m_closestHitFraction);
      }
      m_verticalVelocity = 0.0;
      m_verticalOffset = 0.0;
   } else {
      m_currentStepOffset = m_stepHeight;
      m_currentPosition = m_targetPosition;
   }
}
//---------------------------------------------------------------------------------------
void CharacterController::updateTargetPositionBasedOnCollision (const btVector3& hitNormal, btScalar tangentMag, btScalar normalMag)
{
   btVector3 movementDirection = m_targetPosition - m_currentPosition;
   btScalar movementLength = movementDirection.length();
   if (movementLength>SIMD_EPSILON)
   {
      movementDirection.normalize();

      btVector3 reflectDir = computeReflectionDirection (movementDirection, hitNormal);
      reflectDir.normalize();

      btVector3 parallelDir, perpindicularDir;

      parallelDir = parallelComponent (reflectDir, hitNormal);
      perpindicularDir = perpindicularComponent (reflectDir, hitNormal);

      m_targetPosition = m_currentPosition;
      if (0)//tangentMag != 0.0)
      {
         btVector3 parComponent = parallelDir * btScalar (tangentMag*movementLength);
//         printf("parComponent=%f,%f,%f\n",parComponent[0],parComponent[1],parComponent[2]);
         m_targetPosition +=  parComponent;
      }

      if (normalMag != 0.0)
      {
         btVector3 perpComponent = perpindicularDir * btScalar (normalMag*movementLength);
//         printf("perpComponent=%f,%f,%f\n",perpComponent[0],perpComponent[1],perpComponent[2]);
         m_targetPosition += perpComponent;
      }
   } else
   {
//      printf("movementLength don't normalize a zero vector\n");
   }
}
//---------------------------------------------------------------------------------------
void CharacterController::stepForwardAndStrafe ( btCollisionWorld* collisionWorld, const btVector3& walkMove)
{
   // printf("m_normalizedDirection=%f,%f,%f\n",
   //    m_normalizedDirection[0],m_normalizedDirection[1],m_normalizedDirection[2]);
   // phase 2: forward and strafe
   btTransform start, end;
   m_targetPosition = m_currentPosition + walkMove;

   start.setIdentity ();
   end.setIdentity ();
   
   btScalar fraction = 1.0;
   btScalar distance2 = (m_currentPosition-m_targetPosition).length2();
//   printf("distance2=%f\n",distance2);

   if (m_touchingContact)
   {
      if (m_normalizedDirection.dot(m_touchingNormal) > btScalar(0.0))
      {
         updateTargetPositionBasedOnCollision (m_touchingNormal);
      }
   }

   int maxIter = 10;

   while (fraction > btScalar(0.01) && maxIter-- > 0)
   {
      start.setOrigin (m_currentPosition);
      end.setOrigin (m_targetPosition);
      btVector3 sweepDirNegative(m_currentPosition - m_targetPosition);

      btKinematicClosestNotMeConvexResultCallback callback (m_ghostObject, sweepDirNegative, btScalar(0.0));
      callback.m_collisionFilterGroup = getGhostObject()->getBroadphaseHandle()->m_collisionFilterGroup;
      callback.m_collisionFilterMask = getGhostObject()->getBroadphaseHandle()->m_collisionFilterMask;


      btScalar margin = m_convexShape->getMargin();
      m_convexShape->setMargin(margin + m_addedMargin);


      if (m_useGhostObjectSweepTest)
      {
         m_ghostObject->convexSweepTest (m_convexShape, start, end, callback, collisionWorld->getDispatchInfo().m_allowedCcdPenetration);
      } else
      {
         collisionWorld->convexSweepTest (m_convexShape, start, end, callback, collisionWorld->getDispatchInfo().m_allowedCcdPenetration);
      }
      
      m_convexShape->setMargin(margin);

      
      fraction -= callback.m_closestHitFraction;

      if (callback.hasHit())
      {   
         // we moved only a fraction
         btScalar hitDistance;
         hitDistance = (callback.m_hitPointWorld - m_currentPosition).length();

//         m_currentPosition.setInterpolate3 (m_currentPosition, m_targetPosition, callback.m_closestHitFraction);

         updateTargetPositionBasedOnCollision (callback.m_hitNormalWorld);
         btVector3 currentDir = m_targetPosition - m_currentPosition;
         distance2 = currentDir.length2();
         if (distance2 > SIMD_EPSILON)
         {
            currentDir.normalize();
            /* See Quake2: "If velocity is against original velocity, stop ead to avoid tiny oscilations in sloping corners." */
            if (currentDir.dot(m_normalizedDirection) <= btScalar(0.0))
            {
               break;
            }
         } else
         {
//            printf("currentDir: don't normalize a zero vector\n");
            break;
         }

      } else {
         // we moved whole way
         m_currentPosition = m_targetPosition;
      }

   //   if (callback.m_closestHitFraction == 0.f)
   //      break;

   }
}
//---------------------------------------------------------------------------------------
void CharacterController::stepDown ( btCollisionWorld* collisionWorld, btScalar dt)
{
   btTransform start, end;

   // phase 3: down
   /*btScalar additionalDownStep = (m_wasOnGround && !onGround()) ? m_stepHeight : 0.0;
   btVector3 step_drop = getUpAxisDirections()[m_upAxis] * (m_currentStepOffset + additionalDownStep);
   btScalar downVelocity = (additionalDownStep == 0.0 && m_verticalVelocity<0.0?-m_verticalVelocity:0.0) * dt;
   btVector3 gravity_drop = getUpAxisDirections()[m_upAxis] * downVelocity;
   m_targetPosition -= (step_drop + gravity_drop);*/

   btScalar downVelocity = (m_verticalVelocity<0.f?-m_verticalVelocity:0.f) * dt;
   if(downVelocity > 0.0// && downVelocity < m_stepHeight //TEST
      && (m_wasOnGround || !m_wasJumping))
   {
      //if (downVelocity < m_stepHeight) //TODO to jak do ziemi <m_stepHeight
      //   downVelocity = m_stepHeight;
      ////TEST for better falling
         if(downVelocity > m_fallSpeed)
            downVelocity = m_fallSpeed;
      ////TEST END

      //downVelocity = m_stepHeight;
   }

   btVector3 step_drop = getUpAxisDirections()[m_upAxis] * (m_currentStepOffset + downVelocity);
   m_targetPosition -= step_drop;

   start.setIdentity ();
   end.setIdentity ();

   start.setOrigin (m_currentPosition);
   end.setOrigin (m_targetPosition);

   btKinematicClosestNotMeConvexResultCallback callback (m_ghostObject, getUpAxisDirections()[m_upAxis], m_maxSlopeCosine);
   callback.m_collisionFilterGroup = getGhostObject()->getBroadphaseHandle()->m_collisionFilterGroup;
   callback.m_collisionFilterMask = getGhostObject()->getBroadphaseHandle()->m_collisionFilterMask;
   
   if (m_useGhostObjectSweepTest)
   {
      m_ghostObject->convexSweepTest (m_convexShape, start, end, callback, collisionWorld->getDispatchInfo().m_allowedCcdPenetration);
   } else
   {
      collisionWorld->convexSweepTest (m_convexShape, start, end, callback, collisionWorld->getDispatchInfo().m_allowedCcdPenetration);
   }

   if (callback.hasHit())
   {
      // we dropped a fraction of the height -> hit floor
      m_currentPosition.setInterpolate3 (m_currentPosition, m_targetPosition, callback.m_closestHitFraction);
      m_verticalVelocity = 0.0;
      m_verticalOffset = 0.0;
      m_wasJumping = false;
   } else {
      // we dropped the full height
      
      m_currentPosition = m_targetPosition;
   }
}
//---------------------------------------------------------------------------------------
void CharacterController::setWalkDirection(const btVector3& walkDirection)
{
   m_useWalkDirection = true;
   m_walkDirection = walkDirection;
   m_normalizedDirection = getNormalizedVector(m_walkDirection);
}
//---------------------------------------------------------------------------------------
void CharacterController::setVelocityForTimeInterval(const btVector3& velocity, btScalar timeInterval)
{
//   printf("setVelocity!\n");
//   printf("  interval: %f\n", timeInterval);
//   printf("  velocity: (%f, %f, %f)\n",
//       velocity.x(), velocity.y(), velocity.z());

   m_useWalkDirection = false;
   m_walkDirection = velocity;
   m_normalizedDirection = getNormalizedVector(m_walkDirection);
   m_velocityTimeInterval = timeInterval;
}
//---------------------------------------------------------------------------------------
void CharacterController::reset ()
{
}
//---------------------------------------------------------------------------------------
void CharacterController::warp (const btVector3& origin)
{
   btTransform xform;
   xform.setIdentity();
   xform.setOrigin (origin);
   m_ghostObject->setWorldTransform (xform);
}
//---------------------------------------------------------------------------------------
void CharacterController::preStep (  btCollisionWorld* collisionWorld)
{
   
   int numPenetrationLoops = 0;
   m_touchingContact = false;
   while (recoverFromPenetration (collisionWorld))
   {
      numPenetrationLoops++;
      m_touchingContact = true;
      if (numPenetrationLoops > 4)
      {
         //printf("character could not recover from penetration = %d\n", numPenetrationLoops);
         break;
      }
   }

   m_currentPosition = m_ghostObject->getWorldTransform().getOrigin();
   m_targetPosition = m_currentPosition;
//   printf("m_targetPosition=%f,%f,%f\n",m_targetPosition[0],m_targetPosition[1],m_targetPosition[2]);
}
//---------------------------------------------------------------------------------------
//#include <stdio.h>

void CharacterController::playerStep (  btCollisionWorld* collisionWorld, btScalar dt)
{
//   printf("playerStep(): ");
//   printf("  dt = %f", dt);

   // quick check...
   if (!m_useWalkDirection && m_velocityTimeInterval <= 0.0) {
//      printf("\n");
      return;      // no motion
   }

   m_wasOnGround = onGround();

   // Update fall velocity.
   m_verticalVelocity -= m_gravity * dt;
   if(m_verticalVelocity > 0.0 && m_verticalVelocity > m_jumpSpeed)
   {
      m_verticalVelocity = m_jumpSpeed;
   }
   if(m_verticalVelocity < 0.0 && btFabs(m_verticalVelocity) > m_fallSpeed)
   {
      m_verticalVelocity = -m_fallSpeed;
   }
   m_verticalOffset = m_verticalVelocity * dt;


   btTransform xform;
   xform = m_ghostObject->getWorldTransform ();

//   printf("walkDirection(%f,%f,%f)\n",walkDirection[0],walkDirection[1],walkDirection[2]);
//   printf("walkSpeed=%f\n",walkSpeed);

   stepUp (collisionWorld);
   if (m_useWalkDirection) {
      stepForwardAndStrafe (collisionWorld, m_walkDirection);
   } else {
      //printf("  time: %f", m_velocityTimeInterval);
      // still have some time left for moving!
      btScalar dtMoving =
         (dt < m_velocityTimeInterval) ? dt : m_velocityTimeInterval;
      m_velocityTimeInterval -= dt;

      // how far will we move while we are moving?
      btVector3 move = m_walkDirection * dtMoving;

      //printf("  dtMoving: %f", dtMoving);

      // okay, step
      stepForwardAndStrafe(collisionWorld, move);
   }
   stepDown (collisionWorld, dt);

   // printf("\n");

   xform.setOrigin (m_currentPosition);
   m_ghostObject->setWorldTransform (xform);
}
//---------------------------------------------------------------------------------------
void CharacterController::jump ()
{
   if (!canJump())
      return;

   m_verticalVelocity = m_jumpSpeed;
   m_wasJumping = true;

#if 0
   currently no jumping.
   btTransform xform;
   m_rigidBody->getMotionState()->getWorldTransform (xform);
   btVector3 up = xform.getBasis()[1];
   up.normalize ();
   btScalar magnitude = (btScalar(1.0)/m_rigidBody->getInvMass()) * btScalar(8.0);
   m_rigidBody->applyCentralImpulse (up * magnitude);
#endif
}
//---------------------------------------------------------------------------------------
btVector3* CharacterController::getUpAxisDirections()
{
   static btVector3 sUpAxisDirection[3] = { btVector3(1.0f, 0.0f, 0.0f), btVector3(0.0f, 1.0f, 0.0f), btVector3(0.0f, 0.0f, 1.0f) };
   
   return sUpAxisDirection;
}
//---------------------------------------------------------------------------------------
void CharacterController::debugDraw(btIDebugDraw* debugDrawer)
{
   debugDrawer;
}
//---------------------------------------------------------------------------------------

// oije_charactercontroller.cpp - End of file


BulletTriggerTest.cpp
Code:
/**
 * BulletTriggerTest.cpp
 *
 * 2010 Marzena Gasidło (Ocelot).
 * http://www.ocelotsjungle.republika.pl/
 *
 * -----------------------------------------------------------------------------
 *
 * REVISION HISTORY:
 *
 *  12/07(Jul)/2010: Ocelot - Original creation
 *
 * -----------------------------------------------------------------------------
 *
 * Licence:
 *
 *   Bullet Continuous Collision Detection and Physics Library
 *   Copyright (c) 2003-2008 Erwin Coumans  http://bulletphysics.com
 *
 *   This software is provided 'as-is', without any express or implied warranty.
 *   In no event will the authors be held liable for any damages arising from the use of this software.
 *   Permission is granted to anyone to use this software for any purpose,
 *   including commercial applications, and to alter it and redistribute it freely,
 *   subject to the following restrictions:
 *
 *   1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
 *   2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
 *   3. This notice may not be removed or altered from any source distribution.
 */

#pragma warning( disable : 4100 4127 )
#include <btBulletDynamicsCommon.h>
#include <BulletCollision/CollisionDispatch/btGhostObject.h>
#include "oije_charactercontroller.h"
#pragma warning( default : 4100 4127 )
#include <iostream>
#include <vector>

#define LOG(t) std::cout<<t<<std::endl;

btDiscreteDynamicsWorld* dynamicsWorld=0;

//---------------------------------------------------------------------------------------
enum EPhysicsCollisionMask {

   E_Static   = 1 << 0,
   E_Riggid   = 1 << 1,
   E_Actor      = 1 << 2,
   E_Trigger   = 1 << 3,
   
   E_StaticGroup   = E_Riggid | E_Actor,
   E_ActorGroup   = E_Static | E_Riggid | E_Actor | E_Trigger,
   E_RiggidGroup   = E_Static | E_Riggid | E_Actor | E_Trigger ,
   E_TriggerGroup   = E_Riggid | E_Actor
};
//---------------------------------------------------------------------------------------
struct FilterCallback : public btOverlapFilterCallback {

   // return true when pairs need collision
   virtual bool needBroadphaseCollision(btBroadphaseProxy* proxy0, btBroadphaseProxy* proxy1) const override
   {
      bool collides = (proxy0->m_collisionFilterGroup & proxy1->m_collisionFilterMask) &&
                  (proxy1->m_collisionFilterGroup & proxy0->m_collisionFilterMask);
      //add some additional logic here that modified 'collides'
      return collides;
   }
};
//---------------------------------------------------------------------------------------
void checkGhost(btPairCachingGhostObject* ghostObject) {

   btManifoldArray   manifoldArray;
   btBroadphasePairArray& pairArray = ghostObject->getOverlappingPairCache()->getOverlappingPairArray();
   int numPairs = pairArray.size();

   for (int i=0;i<numPairs;i++)
   {
      manifoldArray.clear();

      const btBroadphasePair& pair = pairArray[i];

      //unless we manually perform collision detection on this pair, the contacts are in the dynamics world paircache:
      btBroadphasePair* collisionPair = dynamicsWorld->getPairCache()->findPair(pair.m_pProxy0,pair.m_pProxy1);
      if (!collisionPair)
         continue;
      if (collisionPair->m_algorithm)
         collisionPair->m_algorithm->getAllContactManifolds(manifoldArray);

      for (int j=0;j<manifoldArray.size();j++){
         btPersistentManifold* manifold = manifoldArray[j];
         if (manifold->getNumContacts()){
            int id = reinterpret_cast<int>((manifold->getBody0()!=ghostObject)?static_cast<btCollisionObject*>(manifold->getBody0())->getUserPointer():
                                                               static_cast<btCollisionObject*>(manifold->getBody1())->getUserPointer());
            LOG("\tcontact ("<<manifold->getNumContacts()<<") : "<<((id==1)?"box":"actor"));   
         }
      }
   }
}
//---------------------------------------------------------------------------------------
int main(int argc, char* argv[]) {

   btDefaultCollisionConfiguration* conf      = new btDefaultCollisionConfiguration();
   btCollisionDispatcher* dispatcher         = new btCollisionDispatcher(conf);
   btBroadphaseInterface* overlappingPairCache = new btDbvtBroadphase();
   btSequentialImpulseConstraintSolver* solver = new btSequentialImpulseConstraintSolver;

   //world
   dynamicsWorld = new btDiscreteDynamicsWorld(dispatcher, overlappingPairCache, solver, conf);
   dynamicsWorld->setGravity(btVector3(0,-10,0));

   // broadphase filter callback
   btOverlapFilterCallback * filterCallback = new FilterCallback();
   dynamicsWorld->getPairCache()->setOverlapFilterCallback(filterCallback);

   std::vector<btCollisionShape*> shapes;

   //------------------------------ ground - static plane ------------------------------
   btCollisionShape* groundShape = new btStaticPlaneShape(btVector3(0,1,0), 1);
   shapes.push_back(groundShape);
   btDefaultMotionState* groundMotionState = new btDefaultMotionState(btTransform(btQuaternion(0,0,0,1), btVector3(0,-1,0)));
   btRigidBody::btRigidBodyConstructionInfo groundRigidBodyCI(0, groundMotionState, groundShape, btVector3(0,0,0));
   btRigidBody* groundRigidBody = new btRigidBody(groundRigidBodyCI);
   dynamicsWorld->addRigidBody(groundRigidBody, E_Static, E_Riggid | E_Actor);
   
   //------------------------------ ghost ------------------------------
   btCollisionShape* ghostShape = new btBoxShape(btVector3(10, 1, 10));
   shapes.push_back(ghostShape);   
   
   btTransform transform;
   transform.setIdentity();
   transform.setOrigin(btVector3(0.0f, 1.0f, 0.0f));

   btPairCachingGhostObject* ghostObject = new btPairCachingGhostObject();
   ghostObject->setWorldTransform(transform);
   
   btGhostPairCallback* ghostPairCallback = new btGhostPairCallback();
   overlappingPairCache->getOverlappingPairCache()->setInternalGhostPairCallback(ghostPairCallback);

   ghostObject->setCollisionShape(ghostShape);
   ghostObject->setCollisionFlags(ghostObject->getCollisionFlags() | btCollisionObject::CF_NO_CONTACT_RESPONSE);

   //------------------------------ riggid box ------------------------------
   btCollisionShape* fallShape = new btBoxShape(btVector3(1.0, 1.0, 1.0));
   shapes.push_back(fallShape);

   btDefaultMotionState* fallMotionState = new btDefaultMotionState(btTransform(btQuaternion(0,0,0,1), btVector3(5,5,0)));
   btVector3 fallInertia(0,0,0);
   fallShape->calculateLocalInertia(1.0f, fallInertia);

   btRigidBody::btRigidBodyConstructionInfo fallRigidBodyCI(1.0f, fallMotionState, fallShape, fallInertia); // może być wspólne
   btRigidBody* fallRigidBody = new btRigidBody(fallRigidBodyCI);
   fallRigidBody->setUserPointer((void*)1);
   
   //------------------------------ character ------------------------------
   btTransform startTransform;
   startTransform.setIdentity();
   startTransform.setOrigin(btVector3(0, 5, 0)); // check

   btPairCachingGhostObject* actorGhost = new btPairCachingGhostObject();
   actorGhost->setUserPointer((void*)2);
   actorGhost->setWorldTransform(startTransform);
   
   btGhostPairCallback* actorGhostPairCallback = new btGhostPairCallback();
   overlappingPairCache->getOverlappingPairCache()->setInternalGhostPairCallback(actorGhostPairCallback);
   
   actorGhost->setCollisionShape(fallShape);
   actorGhost->setCollisionFlags(btCollisionObject::CF_CHARACTER_OBJECT);

   OiJE::CharacterController* character = new OiJE::CharacterController(actorGhost, static_cast<btConvexShape*>(fallShape), 0.5f);
   
   //------------------------------ add actor to the world ------------------------------
   dynamicsWorld->addCollisionObject(actorGhost, E_Actor, E_Static | E_Riggid | E_Actor | E_Trigger);
   dynamicsWorld->addAction(character);
   
   //------------------------------ add rigid to the world ------------------------------
   dynamicsWorld->addRigidBody(fallRigidBody, E_Riggid, E_Static | E_Riggid | E_Actor | E_Trigger);

   //------------------------------ add ghost to the world ------------------------------
   dynamicsWorld->addCollisionObject(ghostObject, E_Trigger, E_Riggid | E_Actor);

   //------------------------------------ simulation ------------------------------------
   for (int i=0 ; i<230 ; i++) {
      dynamicsWorld->stepSimulation(1/60.f,10);
      LOG(i);
      // --- check ghost
      checkGhost(ghostObject);
      btTransform trans = actorGhost->getWorldTransform();
   }
   //------------------------------------------------------------------------------------
   
   LOG("\nAfter simulation");
   btTransform trans;
   fallRigidBody->getMotionState()->getWorldTransform(trans);
   LOG("box position    should be (5, 1) is : " << trans.getOrigin().getX()<<", "<< trans.getOrigin().getY());
   trans = actorGhost->getWorldTransform();
   LOG("actor position  should be (0, 1) is : " << trans.getOrigin().getX()<<", "<< trans.getOrigin().getY());

   //************* cleanup in the reverse order of creation/initialization
   //remove the rigidbodies from the dynamics world and delete them
   for (int i=dynamicsWorld->getNumCollisionObjects()-1; i>=0 ;i--)   {
      btCollisionObject* obj = dynamicsWorld->getCollisionObjectArray()[i];
      btRigidBody* body = btRigidBody::upcast(obj);
      if (body && body->getMotionState())
         delete body->getMotionState();
      dynamicsWorld->removeCollisionObject( obj );
      delete obj;
   }
   //delete collision shapes
   for( int i=0; i<shapes.size(); ++i)
      delete shapes[i];
   delete dynamicsWorld;
   delete solver;
   delete overlappingPairCache;
   delete dispatcher;
   delete conf;

   LOG("Press <Enter> to end...");std::cin.get();
   return 0;
}
//---------------------------------------------------------------------------------------


Ocelot


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PostPosted: Thu Sep 30, 2010 4:26 pm 
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Joined: Mon Jul 26, 2010 8:03 am
Posts: 14
Thank you so much for putting this here. I was looking into how to start working with the Kinematic Character Controller today and stumbled across this. I don't exactly understand all of it yet (I am pretty new to physics engines as a whole), but a good portion of it makes plenty of sense. I added it to much project and I am working with it now to get it completely functional.

I do have a couple of questions though if you don't mind

1) So when I want to move the Character Controller, what should I be calling? From reading the code, I am assuming I need to call setWalkDirection() and pass it the direction my player is facing and then updateAction()?

2) You obviously know better than me, but in the update() function, isn't a for loop that repeats 230 times per frame a bit much?

3) This is more of a generic question but I will ask. My actual game has a Character class that controls all of the player information, such as the animation, camera, input + movement, etc. I believe what I want to do to add this is pass the CharacterController object to it after it is created, then control the movement of the controller based on the input. Then move the actual mesh and set the animations based on information from the CharacterController?


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PostPosted: Thu Sep 30, 2010 6:42 pm 
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Joined: Sun Sep 12, 2010 10:25 am
Posts: 32
If you scan these forums there are actually 3 or 4 different implementation "fix-ups" for the kinematic character controller. This one may or may not suit your needs (i.e. it still might not be able to climb steps properly with the more realistic fall speed). I believe it also can "push" other rigid bodies in the dynamics world around, but not sure. I have adapted a different character controller patch and am using that one. :)

Anyway, the way you use the character controller is actually a bit more subtle than calling update action yourself, and the original poster's update function was calling StepSimulation 230 times because this was a non-graphical simulation that doesn't run "frame-to-frame".

You "install" the character controller into the dynamics world and then simply step the simulation. As long as the walk direction is { 0, 0, 0 } the character doesn't move. To move them, just tie your game's input routines to adjusting the walk vector each frame and then tie your game camera to focusing on the character controller's position (use getWorldTransform() to read it back). Call StepSimulation in between the two calls.

By adding your action to the dynamics world, it will call update action on your behalf *IF* you call StepSimulation() each frame.

Code:
   m_dynamicsWorld->addCollisionObject(c->getGhostObject(),
                                      btBroadphaseProxy::CharacterFilter,
                              btBroadphaseProxy::StaticFilter | btBroadphaseProxy::DefaultFilter
                              );
   m_dynamicsWorld->addAction( c );


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PostPosted: Fri Oct 01, 2010 5:26 am 
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Joined: Mon Jul 26, 2010 8:03 am
Posts: 14
Thank you so much Steve. I switched to what I think is the same one you are using, and your answer definitely cleared a lot up for me setting up a CharacterController the second time around. I completely missed that before that it automatically moved as soon as you set a walk direction.


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PostPosted: Mon Oct 04, 2010 3:23 pm 
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Joined: Sun Feb 14, 2010 3:09 pm
Posts: 3
Location: Cracow, Poland
The code I post is copy of Bullet (2.77) character controller with some improvements for ghost - character collision, and fall.

Quote:
2) You obviously know better than me, but in the update() function, isn't a for loop that repeats 230 times per frame a bit much?


The test program is only for example of how you can make physics triggers, so delta time isn't realistic.


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PostPosted: Thu Jun 06, 2013 12:35 pm 
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Joined: Tue Jan 24, 2012 5:39 am
Posts: 17
Hey Ocelot,

Thank you so much! You've saved the day! I have fought this for so long. Your first two tweaks fixed it for me.

THANKS!


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PostPosted: Thu Jun 06, 2013 11:38 pm 
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Joined: Tue Jan 24, 2012 5:39 am
Posts: 17
I've logged this as Issue #719, and attached the changes as a patch


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