Good practices
1. Placing the mice in boxes
It is important that from the moment the start frame is passed, nothing obstructs the view of the given box.
When you place your mice, make sure that you won’t pass your arm in front of the box again to place another mouse.
For example, let’s say that you have for boxes B1, B2, B3 & B4 placed from left to right. And you are standing on the left.
In this case, you will have to place the mice in the order: B4, B3, B2, B1. Otherwise, if you place B2 and then B3, your arm will pass in front of B2 when you place B3.
2. Drawing the polygons
The only rule to draw the polygons is to make sure they don’t overlap with each other.
If they overflow from a box, it doesn’t matter.
If you want to account for a mouse only if its hips passed the door, instead of drawing a huge polygon for the mouse area, just draw a shorter box. Note that you are not limited to a rectangle for your boxes.