He knows that you love him no matter what - his security with your unconditional love is a good thing - even though it's not manifesting itself in a desirable way right now.
You have to make pooping in the potty a cause for celebration and a positive thing. I used the Dr. Phil mthod which he promised would work in 2-3 days, and amazingly it did. I am a huge skeptic of this kind of thing but it worked.
You know what thrills your son - thomas the tank train, rescue heros, transformers, a favorite uncle or teenage cousin, whatever. Tell him that when don't need to uses diapers anymore we're going to have a party to celebrate and his favorite person will even call him to tell him how proud he is of this accomplishment. When he poops on the potty at home have a little party - cupcake, streamers, confetti in the air. Then call his favorite person and "leave him a message" that "Sammy used the potty at home - he pooped in the potty - please give _____ that message". Have your actor - or real person call your son. Let him get on the phone - his favorite person will congratulate him over the phone, tell him how proud he is of this great feat. My son was called by "Billy Blazes", the fireman rescue hero (my husband who was at work at the time).
Then for the next 2 or 3 days whenever he uses the potty praise him, give him a cupcake, or a few m&ms, a visit to his favorite playground (right away delayed gratification doesn't work on 3 yr olds). When he doesn't use the potty just clean him up, no negative comments. Be matter of fact - remind him - next time he uses the potty he gets whatever small trinket you've promised.
Finally when you can throw away the diapers have another small party. Have grandma & grandpa over and have pizza or McD's and another cupcake. It's all about positive reinforcement to make it something he WANTS to do.
This worked like a charm for my 3 yr 3 mos old boy 8 years ago! Best of luck - it's so freeing to get rid of those diapers!