Heisserer, who directed Walker in his film 'Hours', said he recalls being won over by the actor's acting skills despite thinking earlier that he wasn't suitable for the role, the New York Daily News reported.
The director said that the 40-year-old actor was a real sweetheart and that they would share silly animal pictures in an attempt to crack each other up.
He added that since the 'Fast and Furious' star's death, he has been a "spaghetti bowl of emotions".
Walker died in a fatal crash when the Porsche Carrera GT he was travelling in crashed into a pole and burst into flames.
--ANI (Posted on 15-12-2013)