BUG: Set default value for PBDModelConfig to fix non-deterministic behaviors

Source/Constraint/PbdConstraints/imstkPbdConstraint.h

@@ -83,6 +83,6 @@ public:
 
 protected:
     std::vector<size_t> m_vertexIds;   ///> index of points for the constraint
-    double m_epsilon = 1.0e-6;         ///> Tolerance used for the costraints
+    double m_epsilon = 1.0e-16;        ///> Tolerance used for the costraints
 };
 }

Source/DynamicalModels/ObjectModels/imstkPbdModel.h

@@ -42,20 +42,20 @@ struct PBDModelConfig
     double m_viscousDampingCoeff = 0.01;     ///> Viscous damping coefficient [0, 1]
 
     double m_contactStiffness = 1.0;         ///> Contact stiffness for collisions
-    double m_proximity;                      ///> Proximity for collisions
+    double m_proximity = 0.1;                ///> Proximity for collisions
 
-    unsigned int m_maxIter;                 ///> Max. pbd iterations
-    double m_dt;                            ///> Time step size
-    double m_DefaultDt;                     ///> Default Time step size
+    unsigned int m_maxIter = 10;                 ///> Max. pbd iterations
+    double m_dt = 0.01;                          ///> Time step size
+    double m_DefaultDt = 0.01;                   ///> Default Time step size
 
     std::vector<std::size_t> m_fixedNodeIds; ///> Nodal IDs of the nodes that are fixed
-    Vec3r m_gravity;                         ///> Gravity
+    Vec3r m_gravity = Vec3r(0, -9.81, 0);                         ///> Gravity
 
-    double m_mu;           ///> Lame constant, if constraint type is FEM
-    double m_lambda;       ///> Lame constant, if constraint type is FEM
+    double m_mu = 0;           ///> Lame constant, if constraint type is FEM
+    double m_lambda = 0;       ///> Lame constant, if constraint type is FEM
 
-    double m_YoungModulus; ///> FEM parameter, if constraint type is FEM
-    double m_PoissonRatio; ///> FEM parameter, if constraint type is FEM
+    double m_YoungModulus = 1000; ///> FEM parameter, if constraint type is FEM
+    double m_PoissonRatio = 0.2;  ///> FEM parameter, if constraint type is FEM
 
     std::vector<std::pair<PbdConstraint::Type, double>>    m_RegularConstraints; ///> Constraints except FEM
     std::vector<std::pair<PbdConstraint::Type,