Use the more accurate, but slightly slower, gjk ray test by default, instead of the sub-simplex convex cast.

Set the rayCallback.m_flag  btTriangleRaycastCallback::kF_UseSubSimplexConvexCastRaytest to enable the previous approximate/faster ray test.

src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp

@@ -294,10 +294,10 @@ void	btCollisionWorld::rayTestSingleInternal(const btTransform& rayFromTrans,con
 		//btContinuousConvexCollision convexCaster(castShape,convexShape,&simplexSolver,0);
 		bool condition = true;
 		btConvexCast* convexCasterPtr = 0;
-		if (resultCallback.m_flags & btTriangleRaycastCallback::kF_UseGjkConvexRaytest)
-			convexCasterPtr = &gjkConvexCaster;
-		else
+		if (resultCallback.m_flags & btTriangleRaycastCallback::kF_UseSubSimplexConvexCastRaytest)
 			convexCasterPtr = &subSimplexConvexCaster;
+		else
+			convexCasterPtr = &gjkConvexCaster;
 		
 		btConvexCast& convexCaster = *convexCasterPtr;
 

src/BulletCollision/NarrowPhaseCollision/btRaycastCallback.h

@@ -35,7 +35,7 @@ public:
       kF_None                 = 0,
       kF_FilterBackfaces      = 1 << 0,
       kF_KeepUnflippedNormal  = 1 << 1,   // Prevents returned face normal getting flipped when a ray hits a back-facing triangle
-	  kF_UseGjkConvexRaytest =  1 << 2,   // Uses a more accurate but slightly slower ray versus convex algorithm
+	  kF_UseSubSimplexConvexCastRaytest =  1 << 2,   // Uses an approximate but faster ray versus convex intersection algorithm
       kF_Terminator        = 0xFFFFFFFF
    };
    unsigned int m_flags;