I worked on the Assembly Line shot with my animation students. I decided to create an assignment where they would break apart a robotic character and move the individual pieces to create the motion. That is what I did in this shot with one of the robotic arms, The base does not move but I broke it into the foreground base and background base. The Upper Arm segment rotated from a round hinge at the base, then the forearm moved at the elbow.
This type of animation can be done in After Effects by assembling a forward kinematics skeleton, but I didn’t want to take the time to set up such a complicated rig. Forward kinematics is where you can move the wrist and the other sections of the arm will follow along with the action.
Instead I animated each section independently. The scene is only 25 frames long so that could be done fairly quickly. An issue that came up is that the center of rotation had to be moved into position for each frame. I placed that center pretty consistently but when the slow in became close there was some jiggling which had to be smoothed out.
I also used the robotic arm to teach anticipation which is when an object moves in the opposite direction a bit before moving forward. The forearm rotates s light bit down before the arm thrusts forward. Anyway animating with the cut out parts did create a robotic feeling animation which is what I needed.
The robotic arm thrusts screen left and then the guy in the hazmat suit moves his arm. I animated that arm move with the students. I had him raise his hand. But in 25 frames I had to end the action before he could place his hand anywhere. That animation that I abandoned made it look like he might slap the woman. I threw out some of the drawings to reduce the speed of the action. During the lunch break, I threw out that animation entirely and decided that he already had his hand on the woman’s forehead and he would draw his hand back and drop it to this side. I decided that was a much more compassionate gesture.
There is tons more action that could be added to the scene since the beds could lurch down the assembly line track, but the robotic arm and gentle touch are all I feel are needed.