Compute the fat AABB by adding a percentage of the size of the initial AABB instead of using a constant offset. Do not use linear displacement anymore in inflate the AABB in direction of the motion in the broad-phase

src/collision/broadphase/DynamicAABBTree.cpp

@@ -35,8 +35,8 @@ using namespace reactphysics3d;
 const int32 TreeNode::NULL_TREE_NODE = -1;
 
 // Constructor
-DynamicAABBTree::DynamicAABBTree(MemoryAllocator& allocator, decimal extraAABBGap)
+DynamicAABBTree::DynamicAABBTree(MemoryAllocator& allocator, decimal fatAABBInflatePercentage)
-                : mAllocator(allocator), mExtraAABBGap(extraAABBGap) {
+                : mAllocator(allocator), mFatAABBInflatePercentage(fatAABBInflatePercentage) {
 
     init();
 }
@@ -135,8 +135,8 @@ int32 DynamicAABBTree::addObjectInternal(const AABB& aabb) {
     // Get the next available node (or allocate new ones if necessary)
     int32 nodeID = allocateNode();
 
-    // Create the fat aabb to use in the tree
+    // Create the fat aabb to use in the tree (inflate the aabb by a constant percentage of its size)
-    const Vector3 gap(mExtraAABBGap, mExtraAABBGap, mExtraAABBGap);
+    const Vector3 gap(aabb.getExtent() * mFatAABBInflatePercentage * decimal(0.5f));
     mNodes[nodeID].aabb.setMin(aabb.getMin() - gap);
     mNodes[nodeID].aabb.setMax(aabb.getMax() + gap);
 
@@ -167,12 +167,11 @@ void DynamicAABBTree::removeObject(int32 nodeID) {
 // Update the dynamic tree after an object has moved.
 /// If the new AABB of the object that has moved is still inside its fat AABB, then
 /// nothing is done. Otherwise, the corresponding node is removed and reinserted into the tree.
-/// The method returns true if the object has been reinserted into the tree. The "displacement"
+/// The method returns true if the object has been reinserted into the tree.
-/// argument is the linear velocity of the AABB multiplied by the elapsed time between two
+/// If the "forceReInsert" parameter is true, we force the existing AABB to take the size
-/// frames. If the "forceReInsert" parameter is true, we force the existing AABB to take the size
 /// of the "newAABB" parameter even if it is larger than "newAABB". This can be used to shrink the
 /// AABB in the tree for instance if the corresponding collision shape has been shrunk.
-bool DynamicAABBTree::updateObject(int32 nodeID, const AABB& newAABB, const Vector3& displacement, bool forceReinsert) {
+bool DynamicAABBTree::updateObject(int32 nodeID, const AABB& newAABB, bool forceReinsert) {
 
     RP3D_PROFILE("DynamicAABBTree::updateObject()", mProfiler);
 
@@ -188,32 +187,12 @@ bool DynamicAABBTree::updateObject(int32 nodeID, const AABB& newAABB, const Vect
     // If the new AABB is outside the fat AABB, we remove the corresponding node
     removeLeafNode(nodeID);
 
-    // Compute the fat AABB by inflating the AABB with a constant gap
+    // Compute the fat AABB by inflating the AABB with by a constant percentage of the size of the AABB
     mNodes[nodeID].aabb = newAABB;
-    const Vector3 gap(mExtraAABBGap, mExtraAABBGap, mExtraAABBGap);
+    const Vector3 gap(newAABB.getExtent() * mFatAABBInflatePercentage * decimal(0.5f));
     mNodes[nodeID].aabb.mMinCoordinates -= gap;
     mNodes[nodeID].aabb.mMaxCoordinates += gap;
 
-    // Inflate the fat AABB in direction of the linear motion of the AABB
-    if (displacement.x < decimal(0.0)) {
-      mNodes[nodeID].aabb.mMinCoordinates.x += DYNAMIC_TREE_AABB_LIN_GAP_MULTIPLIER * displacement.x;
-    }
-    else {
-      mNodes[nodeID].aabb.mMaxCoordinates.x += DYNAMIC_TREE_AABB_LIN_GAP_MULTIPLIER * displacement.x;
-    }
-    if (displacement.y < decimal(0.0)) {
-      mNodes[nodeID].aabb.mMinCoordinates.y += DYNAMIC_TREE_AABB_LIN_GAP_MULTIPLIER * displacement.y;
-    }
-    else {
-      mNodes[nodeID].aabb.mMaxCoordinates.y += DYNAMIC_TREE_AABB_LIN_GAP_MULTIPLIER * displacement.y;
-    }
-    if (displacement.z < decimal(0.0)) {
-      mNodes[nodeID].aabb.mMinCoordinates.z += DYNAMIC_TREE_AABB_LIN_GAP_MULTIPLIER * displacement.z;
-    }
-    else {
-      mNodes[nodeID].aabb.mMaxCoordinates.z += DYNAMIC_TREE_AABB_LIN_GAP_MULTIPLIER * displacement.z;
-    }
-
     assert(mNodes[nodeID].aabb.contains(newAABB));
 
     // Reinsert the node into the tree

src/collision/broadphase/DynamicAABBTree.h

@@ -158,9 +158,8 @@ class DynamicAABBTree {
         /// Number of nodes in the tree
         int32 mNbNodes;
 
-        /// Extra AABB Gap used to allow the collision shape to move a little bit
+        /// The fat AABB is the initial AABB inflated by a given percentage of its size.
-        /// without triggering a large modification of the tree which can be costly
+        decimal mFatAABBInflatePercentage;
-        decimal mExtraAABBGap;
 
 #ifdef IS_PROFILING_ACTIVE
 
@@ -210,7 +209,7 @@ class DynamicAABBTree {
         // -------------------- Methods -------------------- //
 
         /// Constructor
-        DynamicAABBTree(MemoryAllocator& allocator, decimal extraAABBGap = decimal(0.0));
+        DynamicAABBTree(MemoryAllocator& allocator, decimal fatAABBInflatePercentage = decimal(0.0));
 
         /// Destructor
         ~DynamicAABBTree();
@@ -225,8 +224,7 @@ class DynamicAABBTree {
         void removeObject(int32 nodeID);
 
         /// Update the dynamic tree after an object has moved.
-        bool updateObject(int32 nodeID, const AABB& newAABB, const Vector3& displacement,
+        bool updateObject(int32 nodeID, const AABB& newAABB, bool forceReinsert = false);
-                          bool forceReinsert = false);
 
         /// Return the fat AABB corresponding to a given node ID
         const AABB& getFatAABB(int32 nodeID) const;

src/configuration.h

@@ -100,14 +100,9 @@ constexpr decimal PI = decimal(3.14159265);
 constexpr decimal PI_TIMES_2 = decimal(6.28318530);
 
 /// In the broad-phase collision detection (dynamic AABB tree), the AABBs are
-/// inflated with a constant gap to allow the collision shape to move a little bit
+/// inflated by a constant percentage of its size to allow the collision shape to move a little bit
-/// without triggering a large modification of the tree which can be costly
+/// without triggering a large modification of the tree each frame which can be costly
-constexpr decimal DYNAMIC_TREE_AABB_GAP = decimal(0.1);
+constexpr decimal DYNAMIC_TREE_FAT_AABB_INFLATE_PERCENTAGE = decimal(0.08);
-
-/// In the broad-phase collision detection (dynamic AABB tree), the AABBs are
-/// also inflated in direction of the linear motion of the body by mutliplying the
-/// followin constant with the linear velocity and the elapsed time between two frames.
-constexpr decimal DYNAMIC_TREE_AABB_LIN_GAP_MULTIPLIER = decimal(1.7);
 
 /// Current version of ReactPhysics3D
 const std::string RP3D_VERSION = std::string("0.7.1");

src/systems/BroadPhaseSystem.cpp

@@ -36,8 +36,8 @@ using namespace reactphysics3d;
 
 // Constructor
 BroadPhaseSystem::BroadPhaseSystem(CollisionDetectionSystem& collisionDetection, ColliderComponents& collidersComponents,
-                                   TransformComponents& transformComponents, RigidBodyComponents &rigidBodyComponents)
+                                   TransformComponents& transformComponents, RigidBodyComponents& rigidBodyComponents)
-                    :mDynamicAABBTree(collisionDetection.getMemoryManager().getPoolAllocator(), DYNAMIC_TREE_AABB_GAP),
+                    :mDynamicAABBTree(collisionDetection.getMemoryManager().getPoolAllocator(), DYNAMIC_TREE_FAT_AABB_INFLATE_PERCENTAGE),
                      mCollidersComponents(collidersComponents), mTransformsComponents(transformComponents),
                      mRigidBodyComponents(rigidBodyComponents), mMovedShapes(collisionDetection.getMemoryManager().getPoolAllocator()),
                      mCollisionDetection(collisionDetection) {
@@ -133,13 +133,13 @@ void BroadPhaseSystem::updateColliders(decimal timeStep) {
 }
 
 // Notify the broad-phase that a collision shape has moved and need to be updated
-void BroadPhaseSystem::updateColliderInternal(int32 broadPhaseId, Collider* collider, const AABB& aabb, const Vector3& displacement,
+void BroadPhaseSystem::updateColliderInternal(int32 broadPhaseId, Collider* collider, const AABB& aabb,
                                               bool forceReInsert) {
 
     assert(broadPhaseId >= 0);
 
     // Update the dynamic AABB tree according to the movement of the collision shape
-    bool hasBeenReInserted = mDynamicAABBTree.updateObject(broadPhaseId, aabb, displacement, forceReInsert);
+    bool hasBeenReInserted = mDynamicAABBTree.updateObject(broadPhaseId, aabb, forceReInsert);
 
     // If the collision shape has moved out of its fat AABB (and therefore has been reinserted
     // into the tree).
@@ -176,16 +176,6 @@ void BroadPhaseSystem::updateCollidersComponents(uint32 startIndex, uint32 nbIte
             const Entity& bodyEntity = mCollidersComponents.mBodiesEntities[i];
             const Transform& transform = mTransformsComponents.getTransform(bodyEntity);
 
-            // If there is a dynamics component for the current entity
-            Vector3 displacement(0, 0, 0);
-            if (mRigidBodyComponents.hasComponent(bodyEntity)) {
-
-                // Get the linear velocity from the dynamics component
-                const Vector3& linearVelocity = mRigidBodyComponents.getLinearVelocity(bodyEntity);
-
-                displacement = timeStep * linearVelocity;
-            }
-
             // Recompute the world-space AABB of the collision shape
             AABB aabb;
             mCollidersComponents.mCollisionShapes[i]->computeAABB(aabb, transform * mCollidersComponents.mLocalToBodyTransforms[i]);
@@ -195,7 +185,7 @@ void BroadPhaseSystem::updateCollidersComponents(uint32 startIndex, uint32 nbIte
             const bool forceReInsert = mCollidersComponents.mHasCollisionShapeChangedSize[i];
 
             // Update the broad-phase state of the collider
-            updateColliderInternal(broadPhaseId, mCollidersComponents.mColliders[i], aabb, displacement, forceReInsert);
+            updateColliderInternal(broadPhaseId, mCollidersComponents.mColliders[i], aabb, forceReInsert);
 
             mCollidersComponents.mHasCollisionShapeChangedSize[i] = false;
         }

src/systems/BroadPhaseSystem.h

@@ -140,7 +140,7 @@ class BroadPhaseSystem {
         // -------------------- Methods -------------------- //
 
         /// Notify the Dynamic AABB tree that a collider needs to be updated
-        void updateColliderInternal(int32 broadPhaseId, Collider* collider, const AABB& aabb, const Vector3& displacement,
+        void updateColliderInternal(int32 broadPhaseId, Collider* collider, const AABB& aabb,
                                     bool forceReInsert);
 
         /// Update the broad-phase state of some colliders components

test/tests/collision/TestDynamicAABBTree.h

@@ -238,10 +238,10 @@ class TestDynamicAABBTree : public Test {
 
             // ---- Update the object AABBs with the initial AABBs (no reinsertion) ----- //
 
-            tree.updateObject(object1Id, aabb1, Vector3::zero());
+            tree.updateObject(object1Id, aabb1);
-            tree.updateObject(object2Id, aabb2, Vector3::zero());
+            tree.updateObject(object2Id, aabb2);
-            tree.updateObject(object3Id, aabb3, Vector3::zero());
+            tree.updateObject(object3Id, aabb3);
-            tree.updateObject(object4Id, aabb4, Vector3::zero());
+            tree.updateObject(object4Id, aabb4);
 
             // AABB overlapping nothing
             overlappingNodes.clear();
@@ -285,10 +285,10 @@ class TestDynamicAABBTree : public Test {
 
             // ---- Update the object AABBs with the initial AABBs (with reinsertion) ----- //
 
-            tree.updateObject(object1Id, aabb1, Vector3::zero());
+            tree.updateObject(object1Id, aabb1);
-            tree.updateObject(object2Id, aabb2, Vector3::zero());
+            tree.updateObject(object2Id, aabb2);
-            tree.updateObject(object3Id, aabb3, Vector3::zero());
+            tree.updateObject(object3Id, aabb3);
-            tree.updateObject(object4Id, aabb4, Vector3::zero());
+            tree.updateObject(object4Id, aabb4);
 
             // AABB overlapping nothing
             overlappingNodes.clear();
@@ -333,10 +333,10 @@ class TestDynamicAABBTree : public Test {
             // ---- Move objects 2 and 3 ----- //
 
             AABB newAABB2(Vector3(-7, 10, -3), Vector3(1, 13, 3));
-            tree.updateObject(object2Id, newAABB2, Vector3::zero());
+            tree.updateObject(object2Id, newAABB2);
 
             AABB newAABB3(Vector3(7, -6, -3), Vector3(9, 1, 3));
-            tree.updateObject(object3Id, newAABB3, Vector3::zero());
+            tree.updateObject(object3Id, newAABB3);
 
             // AABB overlapping object 3
             overlappingNodes.clear();
@@ -424,10 +424,10 @@ class TestDynamicAABBTree : public Test {
 
             // ---- Update the object AABBs with the initial AABBs (no reinsertion) ----- //
 
-            tree.updateObject(object1Id, aabb1, Vector3::zero());
+            tree.updateObject(object1Id, aabb1);
-            tree.updateObject(object2Id, aabb2, Vector3::zero());
+            tree.updateObject(object2Id, aabb2);
-            tree.updateObject(object3Id, aabb3, Vector3::zero());
+            tree.updateObject(object3Id, aabb3);
-            tree.updateObject(object4Id, aabb4, Vector3::zero());
+            tree.updateObject(object4Id, aabb4);
 
             // Ray with no hits
             mRaycastCallback.reset();
@@ -463,10 +463,10 @@ class TestDynamicAABBTree : public Test {
 
             // ---- Update the object AABBs with the initial AABBs (with reinsertion) ----- //
 
-            tree.updateObject(object1Id, aabb1, Vector3::zero());
+            tree.updateObject(object1Id, aabb1);
-            tree.updateObject(object2Id, aabb2, Vector3::zero());
+            tree.updateObject(object2Id, aabb2);
-            tree.updateObject(object3Id, aabb3, Vector3::zero());
+            tree.updateObject(object3Id, aabb3);
-            tree.updateObject(object4Id, aabb4, Vector3::zero());
+            tree.updateObject(object4Id, aabb4);
 
             // Ray with no hits
             mRaycastCallback.reset();
@@ -503,10 +503,10 @@ class TestDynamicAABBTree : public Test {
             // ---- Move objects 2 and 3 ----- //
 
             AABB newAABB2(Vector3(-7, 10, -3), Vector3(1, 13, 3));
-            tree.updateObject(object2Id, newAABB2, Vector3::zero());
+            tree.updateObject(object2Id, newAABB2);
 
             AABB newAABB3(Vector3(7, -6, -3), Vector3(9, 1, 3));
-            tree.updateObject(object3Id, newAABB3, Vector3::zero());
+            tree.updateObject(object3Id, newAABB3);
 
             // Ray that hits object 1, 2
             Ray ray5(Vector3(-4, -5, 0), Vector3(-4, 12, 0));