How did Vin Diesel get Riddick?

How did the popular actor Vin Diesel come to be associated with the character of Riddick? Was it through a particular audition process or did he have a personal connection to the role? Did the filmmakers specifically approach him for the part, or did he express interest in the project? Did his performance in previous action-oriented films play a role in his casting? And, most importantly, what unique qualities does Vin Diesel possess that make him the perfect fit for the enigmatic and dangerous character of Riddick?