Fix entity density not setting and not updating for motion states

interface/src/avatar/AvatarMotionState.cpp

@@ -27,6 +27,10 @@ void AvatarMotionState::handleEasyChanges(uint32_t& flags) {
     if (flags & Simulation::DIRTY_PHYSICS_ACTIVATION && !_body->isActive()) {
         _body->activate();
     }
+
+    if (flags & Simulation::DIRTY_MASS) {
+        updateBodyMassProperties();
+    }
 }
 
 AvatarMotionState::~AvatarMotionState() {

interface/src/avatar/DetailedMotionState.cpp

@@ -31,6 +31,10 @@ void DetailedMotionState::handleEasyChanges(uint32_t& flags) {
     if (flags & Simulation::DIRTY_PHYSICS_ACTIVATION && !_body->isActive()) {
         _body->activate();
     }
+
+    if (flags & Simulation::DIRTY_MASS) {
+        updateBodyMassProperties();
+    }
 }
 
 DetailedMotionState::~DetailedMotionState() {

libraries/entities/src/EntityItemPropertiesDefaults.h

@@ -57,9 +57,9 @@ const glm::vec3 ENTITY_ITEM_DEFAULT_DIMENSIONS = glm::vec3(ENTITY_ITEM_DEFAULT_W
 const float ENTITY_ITEM_DEFAULT_VOLUME = ENTITY_ITEM_DEFAULT_WIDTH * ENTITY_ITEM_DEFAULT_WIDTH * ENTITY_ITEM_DEFAULT_WIDTH;
 const float ENTITY_ITEM_MIN_VOLUME = ENTITY_ITEM_MIN_DIMENSION * ENTITY_ITEM_MIN_DIMENSION * ENTITY_ITEM_MIN_DIMENSION;
 
-const float ENTITY_ITEM_MAX_DENSITY = 10000.0f; // kg/m^3 density of silver
+const float ENTITY_ITEM_MAX_DENSITY = 100000.0f; // kg/m^3 more than 5 times density of tungsten.
-const float ENTITY_ITEM_MIN_DENSITY = 100.0f; // kg/m^3 density of balsa wood
+const float ENTITY_ITEM_MIN_DENSITY = 0.1f; // kg/m^3 ten times less than air density.
-const float ENTITY_ITEM_DEFAULT_DENSITY = 1000.0f;   // density of water
+const float ENTITY_ITEM_DEFAULT_DENSITY = 1000.0f;   // density of water.
 const float ENTITY_ITEM_DEFAULT_MASS = ENTITY_ITEM_DEFAULT_DENSITY * ENTITY_ITEM_DEFAULT_VOLUME;
 
 const glm::vec3 ENTITY_ITEM_DEFAULT_VELOCITY = ENTITY_ITEM_ZERO_VEC3;

libraries/physics/src/EntityMotionState.cpp

@@ -57,10 +57,10 @@ EntityMotionState::EntityMotionState(btCollisionShape* shape, EntityItemPointer
 
     _type = MOTIONSTATE_TYPE_ENTITY;
     assert(_entity);
-    setMass(_entity->computeMass());
     // we need the side-effects of EntityMotionState::setShape() so we call it explicitly here
     // rather than pass the legit shape pointer to the ObjectMotionState ctor above.
     setShape(shape);
+    setMass(_entity->computeMass());
 
     if (_entity->isAvatarEntity() && !_entity->isMyAvatarEntity()) {
         // avatar entities are always thus, so we cache this fact in _ownershipState
@@ -178,6 +178,11 @@ void EntityMotionState::handleEasyChanges(uint32_t& flags) {
             _body->activate();
         }
     }
+
+    if (flags & Simulation::DIRTY_MASS) {
+        setMass(_entity->computeMass());
+        updateBodyMassProperties();
+    }
 }
 
 

libraries/physics/src/ObjectMotionState.cpp

@@ -284,10 +284,6 @@ void ObjectMotionState::handleEasyChanges(uint32_t& flags) {
     if (flags & Simulation::DIRTY_MATERIAL) {
         updateBodyMaterialProperties();
     }
-
-    if (flags & Simulation::DIRTY_MASS) {
-        updateBodyMassProperties();
-    }
 }
 
 void ObjectMotionState::updateBodyMaterialProperties() {