Try to allow cake and plunger to have collision callbacks

src/items/bowling.cpp

@@ -234,12 +234,6 @@ void Bowling::onFireFlyable()
     // this would disable gravity.
     setAdjustUpVelocity(false);
 
-    // unset no_contact_response flags, so that the ball
-    // will bounce off the track
-    int flag = getBody()->getCollisionFlags();
-    flag = flag & (~ btCollisionObject::CF_NO_CONTACT_RESPONSE);
-    getBody()->setCollisionFlags(flag);
-
     // should not live forever, auto-destruct after 20 seconds
     m_max_lifespan = stk_config->time2Ticks(20);
 }   // onFireFlyable

src/items/flyable.cpp

@@ -186,8 +186,6 @@ void Flyable::createPhysics(float forw_offset, const Vec3 &velocity,
         m_body->setLinearVelocity(v);
         if(!rotates) m_body->setAngularFactor(0.0f);   // prevent rotations
     }
-    m_body->setCollisionFlags(m_body->getCollisionFlags() |
-                              btCollisionObject::CF_NO_CONTACT_RESPONSE);
 }   // createPhysics
 
 // -----------------------------------------------------------------------------

src/items/rubber_ball.cpp

@@ -90,6 +90,12 @@ void RubberBall::onFireFlyable()
                   btVector3(.0f,.0f,.0f) /*gravity*/,
                   true /*rotates*/);
 
+    // add no_contact_response flags, so that the ball
+    // will not explode if hitting the track or objects
+    int flag = getBody()->getCollisionFlags();
+    flag |= btCollisionObject::CF_NO_CONTACT_RESPONSE;
+    getBody()->setCollisionFlags(flag);
+
     // Do not adjust the up velocity
     setAdjustUpVelocity(false);
     m_max_lifespan       = stk_config->time2Ticks(9999);