3d object not following its mask. Please Help!

[WatchDogMan1777]

Im following an after effects tuturial and you have to place a 3d object on a camera track point. From there youre supposed to mask the solid object so that it fits exactly onto the phone screen. When I masked the solid object, it doesnt conform exactly to it, it kind of blurs around the edges. Does anyone know why this is? The size of the solid is magnifyed and it is set to add.

[WatchDogMan1777]

SOLVED! By me. Turn on continuous rasterization. Who figures.

[Rick Gerard]

It is hard to tell anything about your problem from that cropped screenshot but 3D Camera Tracking is the very last thing I would use to replace the screen on that phone. What tutorial are you following?  Most of the newer tutorials I see that give folks problems are presented by enthusiasts that have discovered some recipe that works for their specific problem. Always post a link to the tutorial so we can help you figure out where the workflow went wrong. 

I really am curious. Sticking a 3D layer to a phone in someone's hand using AE's built-in trackers is going to be problematic more times than it is going to be successful.