Rendering and its issues.

Like usual, rendering was a bit of hell for me, I always get so much more stressed out and frustrated when rendering. It starts slow, and then it gets even slower and I just lose a tiny bit of hope every time. At first I rendered the geometry layer. This way I would have a film to show even if the hair word render catastrophically. It took 1.5 days but all the frames were finally rendered. When I wanted to check on the frames that night, I already met two problems.

Firstly was this: this is the beginning of the second camera angle. I rendered the first 50 frames on the first day after finishing the first camera angle because I had to wait anyway, so I thought I'd already render another batch. When starting rendering the following morning I probably made a mistake by scrolling whilst in the second camera angle, causing the view to be more zoomed out. This meant I had to re-render the first batch, since the hair layer (if this would be rendered correctly) would fit on the second part.

The second problem I encountered is that the alarm clock suddenly disappeared. There are two alarm clocks in the scene, one before and while it gets picked up and the moment it gets put down, the first one goes invisible and the second one appears. I did this because I had a bit of an issue with the constraints and after putting it down, the alarm wouldn't stay in its place. When I made a playblast before I started rendering, it was still there, so something must've gone wrong right before I started rendering, because in the file of the scene I created especially for rendering the alarm disappears, but it's still there in the former file. 

I tackled the alarm clock issue by rendering a single frame of camera angle 3, 4 and 5 so I could composite the alarm into the scene. With a pen tool-mask I singled out the alarm in the frame so it could be placed on top of the image sequence. Since the girl is in front of the alarm sometime I had to either alter the frame with the alarm or alter the sequence. I decided to duplicate the image sequences and place them on top of the alarmfiles. Using the roto-brush tool I singled out the pieces of her that cover the alarm and by layering those sequences on top of the alarm it was fixed again.

How to prevent the first problem is to better check the cameras before I start rendering, I'm lucky this time it was only 50-something frames that needed to be re-rendered, so it wasn't that much extra work and effort.
Since I'm not sure how it's possible that the alarm disappeared since it's still on "visible" in the scene itself, but I couldn't find it anywhere in the scene, I'm not really sure how to fix this problem. In the first place it's better to check the scene thoroughly before rendering to see if everything is still in its right place, and if something is off, it's better to check and fix it before hand than having to put extra effort in post-production.