found better compliance

Source/PBDRobotics/Joint.cpp

@@ -41,7 +41,7 @@ void UJoint::SolvePosition(const double H) const{
 		const double W1 = L1->GetPositionalInverseMass(R1, N);
 		const double W2 = L2->GetPositionalInverseMass(R2, N);
 
-		constexpr double A = 1. / 10000000; // Compliance (inverse of stiffness)
+		constexpr double A = 1. / 1000000; // Compliance (inverse of stiffness)
 		const Vector3d P = -C / (W1 + W2 + A / (H * H)) * N;
 	
 		L1->Position += P / M1;