simplified Aabb management for GhostObject

libraries/physics/src/CharacterController.cpp

@@ -11,6 +11,8 @@
 
 #include "CharacterController.h"
 
+//#include <BulletCollision/BroadphaseCollision/btBroadphaseProxy.h>
+
 #include <NumericalConstants.h>
 
 #include "ObjectMotionState.h"
@@ -121,7 +123,9 @@ void CharacterController::setDynamicsWorld(btDynamicsWorld* world) {
             _dynamicsWorld->addAction(this);
             // restore gravity settings
             _rigidBody->setGravity(oldGravity);
-            _ghost.setCollisionShape(_rigidBody->getCollisionShape()); // KINEMATIC_CONTROLLER_HACK
+            btCollisionShape* shape = _rigidBody->getCollisionShape();
+            assert(shape && shape->getShapeType() == CAPSULE_SHAPE_PROXYTYPE);
+            _ghost.setCharacterShape(static_cast<btCapsuleShape*>(shape)); // KINEMATIC_CONTROLLER_HACK
         }
         // KINEMATIC_CONTROLLER_HACK
         _ghost.setCollisionGroupAndMask(_collisionGroup, BULLET_COLLISION_MASK_MY_AVATAR & (~ _collisionGroup));

libraries/physics/src/CharacterGhostObject.cpp

@@ -13,6 +13,7 @@
 
 #include <assert.h>
 
+#include "CharacterGhostShape.h"
 #include "CharacterRayResult.h"
 
 const btScalar DEFAULT_STEP_UP_HEIGHT = 0.5f;
@@ -20,7 +21,11 @@ const btScalar DEFAULT_STEP_UP_HEIGHT = 0.5f;
 
 CharacterGhostObject::~CharacterGhostObject() {
     removeFromWorld();
-    setCollisionShape(nullptr);
+    if (_ghostShape) {
+        delete _ghostShape;
+        _ghostShape = nullptr;
+        setCollisionShape(nullptr);
+    }
 }
 
 void CharacterGhostObject::setCollisionGroupAndMask(int16_t group, int16_t mask) {
@@ -50,17 +55,14 @@ void CharacterGhostObject::setMotorVelocity(const btVector3& velocity) {
 }
 
 // override of btCollisionObject::setCollisionShape()
-void CharacterGhostObject::setCollisionShape(btCollisionShape* shape) {
-    assert(!shape || shape->isConvex()); // if shape is valid then please make it convex
-    if (shape != getCollisionShape()) {
-        bool wasInWorld = _inWorld;
-        removeFromWorld();
-        btCollisionObject::setCollisionShape(shape);
-        if (wasInWorld) {
-            assert(shape); // please remove from world before setting null shape
-            addToWorld();
-        }
+void CharacterGhostObject::setCharacterShape(btCapsuleShape* capsule) {
+    assert(capsule);
+    // we create our own CharacterGhostShape which has a larger Aabb for more reliable sweep tests
+    if (_ghostShape) {
+        delete _ghostShape;
     }
+    _ghostShape = new CharacterGhostShape(capsule->getRadius(), 2.0f * capsule->getHalfHeight());
+    setCollisionShape(_ghostShape);
 }
 
 void CharacterGhostObject::setCollisionWorld(btCollisionWorld* world) {
@@ -125,20 +127,6 @@ void CharacterGhostObject::move(btScalar dt, btScalar overshoot) {
     btScalar longSweepDistance = stepDistance + overshoot;
     forwardSweep *= longSweepDistance / stepDistance;
 
-    // expand this object's Aabb in the broadphase and
-    // update the pairCache for the sweepTests we intend to do
-    btVector3 minAabb, maxAabb;
-    getCollisionShape()->getAabb(getWorldTransform(), minAabb, maxAabb);
-    minAabb.setMin(minAabb - btVector3(margin, margin, margin));
-    maxAabb.setMax(maxAabb + btVector3(margin, margin, margin));
-    minAabb.setMin(minAabb + forwardSweep);
-    maxAabb.setMax(maxAabb + forwardSweep);
-    minAabb.setMin(minAabb + _maxStepHeight * _upDirection);
-    maxAabb.setMax(maxAabb + _maxStepHeight * _upDirection);
-
-    // this updates both pairCaches: world broadphase and ghostobject
-    _world->getBroadphase()->setAabb(getBroadphaseHandle(), minAabb, maxAabb, _world->getDispatcher());
-
     // step forward
     CharacterSweepResult result(this);
     btTransform startTransform = getWorldTransform();
@@ -338,7 +326,6 @@ void CharacterGhostObject::refreshOverlappingPairCache() {
     assert(_world && _inWorld);
     btVector3 minAabb, maxAabb;
     getCollisionShape()->getAabb(getWorldTransform(), minAabb, maxAabb);
-
     // this updates both pairCaches: world broadphase and ghostobject
     _world->getBroadphase()->setAabb(getBroadphaseHandle(), minAabb, maxAabb, _world->getDispatcher());
 }

libraries/physics/src/CharacterGhostObject.h

@@ -18,6 +18,7 @@
 #include "CharacterSweepResult.h"
 #include "CharacterRayResult.h"
 
+class CharacterGhostShape;
 
 class CharacterGhostObject : public btPairCachingGhostObject {
 public:
@@ -36,7 +37,7 @@ public:
 
     const btVector3& getLinearVelocity() const { return _linearVelocity; }
 
-    void setCollisionShape(btCollisionShape* shape) override;
+    void setCharacterShape(btCapsuleShape* capsule);
 
     void setCollisionWorld(btCollisionWorld* world);
 
@@ -72,10 +73,12 @@ protected:
     btScalar _gravity { 0.0f }; // input, amplitude of gravity along _upDirection (should be negative)
     btScalar _maxWallNormalUpComponent { 0.0f }; // input: max vertical component of wall normal
     btScalar _maxStepHeight { 0.0f }; // input, max step height the character can climb
+    btCapsuleShape* _characterShape { nullptr }; // input, shape of character
+    CharacterGhostShape* _ghostShape{ nullptr }; // internal, shape whose Aabb is used for overlap cache
     int16_t _collisionFilterGroup { 0 };
     int16_t _collisionFilterMask { 0 };
     bool _inWorld { false }; // internal, was added to world
-    bool _hovering { false }; // internal, 
+    bool _hovering { false }; // internal,
     bool _onFloor { false }; // output, is actually standing on floor
     bool _hasFloor { false }; // output, has floor underneath to fall on
 };

libraries/physics/src/CharacterGhostShape.cpp

@@ -0,0 +1,20 @@
+//
+//  CharacterGhostShape.cpp
+//  libraries/physcis/src
+//
+//  Created by Andrew Meadows 2016.09.14
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "CharacterGhostShape.h"
+
+void CharacterGhostShape::getAabb (const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const {
+    btCapsuleShape::getAabb(t, aabbMin, aabbMax);
+    // double the size of the Aabb by expanding both corners by half the extent
+    btVector3 expansion = 0.5f * (aabbMax - aabbMin);
+    aabbMin -= expansion;
+    aabbMax += expansion;
+}

libraries/physics/src/CharacterGhostShape.h

@@ -0,0 +1,26 @@
+//
+//  CharacterGhostShape.h
+//  libraries/physcis/src
+//
+//  Created by Andrew Meadows 2016.09.14
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#ifndef hifi_CharacterGhostShape_h
+#define hifi_CharacterGhostShape_h
+
+#include <BulletCollision/CollisionShapes/btCapsuleShape.h>
+
+class CharacterGhostShape : public btCapsuleShape {
+    // Same as btCapsuleShape but reports an expanded Aabb for larger ghost overlap cache
+public:
+    CharacterGhostShape(btScalar radius, btScalar height) : btCapsuleShape(radius, height) {
+    }
+
+    virtual void getAabb (const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const override;
+};
+
+#endif // hifi_CharacterGhostShape_h