I’ve haven’t used Mocha in a couple years and had a project with phone screen replacements. Out of the several shots, most of it came back and I was able to easily to everything except one shot is more difficult. Right now, I’m just use Mocha AE.
In the clip below, I can do the opening part including the thumb and the end section. It’s the part when the phone gets close to the shoulder and turns that’s proving to be an issue for me. My main weakness with Mocha has always been the Adjust Track function. Not sure if that’s where I need to watch more videos to solve this or not. Thanks in advance.
Difficult Track
Hi, yes, because a large part of the screen is going out of frame, it would require some manual correction and AdjustTrack is the way to go. Here’s the most complete video about it
Speaking of your particular shot, you do not have tracking markers or clear features to place the points. However, there’s a trick you can do. Enable the Planar Grid, and adjust it’s size and number of columns to match that black area on the screen as close as possible. Now you can use the grid as a guide, just by looking at it, as you align the surface with the Adjust Track.
Here’s a rough representation of what I mean. I marked the area that you have to pay attention in Yellow.
And surely you would want to avoid the shoulder and fingers with occlusion masks.
I wonder if this shot is under NDA or is it available for maybe making into a Quick Tip tutorial on this technique later on?
Thanks for the reply. Yes, I’m good with the occlusions and masking those. Many hours of watching the Ginger Mocha Wonder, Mary. ha. I’ll watch the video and post an update soon. I’ve gotten so used to Mocha be so good at tracking the texture, that I usually just say "give me something on the screen, some tape or nothing. I’ve done them all, but the turn and off-screen on this one is tricky since I’ve been away.
I’ll also inquire about using that clip. That would be great.
That was a good move, ha! Most likely some section of this clip would feel more like a manual animation rather than tracking. Hope you can figure it
Great video by the way. Only one critique, smile more! 
I’m in the trap you showed in the video of trying to manually move those corners that I can’t see, but there is always a wobble in the motion. I’m hitting my head on the desk.
Are you tracking with all the motion types turned on? Try leaving only the Translation tracking on that hardest bit, and keyframe the rest. Manual track could be painfull sometimes 
