Motion Capture vs. Keyframe Animation
According to Gerry Anderson himself, the new Captain Scarlet episodes have about 80% of the character animation produced by motion capture [1]. That is definitely understandable because of the large number of characters multiplied by the amount of movement and again multiplied by the number of episodes that have to be released in a certain timeframe. This would take a very long time to animate using traditional keyframe animation techniques and even then the final 
product wouldn't look nearly as natural as it does right now. For example, in the image on the right (14:20) we can see that the pose of the character in the middle looks very natural and relaxed. Also little subtleties such as the character bouncing just a bit while stepping down the stairs just add to the realism which would be difficult and time consuming to achieve using just keyframe animation. Another difficulty in keyframe animation is getting the speed of movement correct. Often the animations end up looking too slow or too fast, the characters don't seem to have weight to them and look like they are floating or gliding. None of those problems are present here thanks to the proper use of motion capture. For example, the middle character quickly coming down the stairs looks very realistic, the speed is right (quick but correct), the hips are moving correctly, the arms are responding correctly to the rest of the body and the head is behaves the way it should.
However, the other 20% of character movement had to be animated using keyframe animation. This I would say mostly pertains to specific situations where motion capture is difficult or not necessary. For instance, the animation of characters in vehicles was probably done using keyframing because the motion isn't very complex, the bodies are in a fixed position (eliminating the reaction of head and arms to the body movement) 
and usually they are visible at most down to the waist. Even though the animation in those shots is minimal it is still obvious that keyframing was used. For example in the shot on the right (12:56) her torso is barely moving and it looks a bit stiff while the head looks acceptable. One wouldn't actually expect the body to move much in a fighter plane but that idea could be visually supported with maybe a seatbelt harness holding her tightly in the seat. Also in another shot where Captain Scarlet's vehicle shakes violently due to a nearby explosion, his body reacts to that sudden movement. 
The fact that it reacts to it at all is important and shows the attention was given to detail however, in the image on the left (13:17) it is noticeable that the effect was achieved using keyframing. Something doesn't "look right" with his arms in relation to his head and body. It just doesn't seem like one's arms would end up in that position in such case. On the other hand, the head movement looks a bit more plausible. It actually lags behind the body which is what you would expect in a sudden jerk.
Overall, the motion capture data was used (really) successfully which makes the keyframe animations look significantly worse in comparison. Even still, the keyframing manages to fill the gaps and the details are not that noticeable in fast moving scenes such as this one.
Facial Animation
Facial animation is probably the most difficult aspect of animating human characters but the animators seem to have put some effort towards giving characters facial expressions. 
Some basic changes in mood are present such as a feeling of satisfaction in the image on the left (12:42) and focus on the right (13:09). The fact that the eyes and the eyelids move helps the realism even more and it is less often the case that the character seems to look "through" things instead of looking at them. Facial expression also gives characters a personality which is crucial in a show like this where emphasis is placed on interaction between characters. For example the Commander always seems to have a grin on his face which is what we've come to expect in movies. On the other hand, the main female character has a very likeable, friendly face and comes through as such in the episodes. The interesting thing is that the main character's face actually doesn't show that much personality and looks the most generic. This may, however, be on purpose since he is a replica.
Hair Animation
There actually is none. The hair is static and moves directly with the head. Nobody has long, 
wavy or puffy hair but rather short and stiff hair and the characters often wear hats.All of this eliminates the need to animate hair which can be quite complicated if one wanted to make it look right. Of course this doesn't look very realistic but then again since the hair is so short or because of the hats it doesn't stand out. This seems like an appropriate simplification since time is better spent on something that will be more perceptible to the viewer.
Clothing
This is very similar to hair in a sense that some rules have been employed in order to minimize the need for realistic looking clothing. For example, all of the characters wear either form fitting, tight suits or have stiff armour over them. This allows the form fitting clothing to move directly with the body or the armour to stay fixed to the torso and allow the arms to move independently.
[1] Questions for Gerry Anderson.
<<< back forward >>>