Whilst the mouth was the most complicated section in terms of morpher and modelling, the arms (and more specifically, the hands) require the greatest level of accuracy and finesse in terms of rigging and movement. Nothing will ruin the final video more than a poorly constructed hand which can barely grip a chess piece, let alone incorporate the smaller digit movements I wish to include!
As before - Punch a hole into Carl and build the body part onto it.
The arm started life as a simple cylinder. However, the important detail was that it specifically had just 8 sides. The reason for this was to allow the arm to connect perfectly to the shoulder joint. If you look at the first image, you will notice that the shoulder has 8 vertices making up the border. In lieu of this, the arm itself also has 8 vertices, so that both can be fused together without any leftover vertices causing a nuisance. The arm was also broken into several segments: 1 small segment added to one end for the shoulder joint - 3 edges added near the centre to form the elbow joint - and 3 at the end to form the wrist. It's these vital edges which will hold the key changes in shape when the bones are added.
The hand started life as a simple cuboid. It's structure was very specific, however: 3 segments high, 3 long and 5 wide. The reason why is shown below:
If you look closely, the fingers are extended from the cuboid, with tiny gaps in between. This is where the width of 5 segments comes in. 2 of them are very thin bridges between the other 3, which host the fingers. The length of 3 is required so that the thumb can be built in the middle of the hand (Note: This is later changed to the end segment by the wrist). The height of 3 also allows the hand to host contours, rather than retain a cuboid shape. The intricate details of the digits are outlined below:
The fingers are made of 2 sections (Later upgraded to 3), and the thumb comprises of 1 (Later upgraded to 2), all of which are bridged with 3 tiny edges. The reason for the 3 edges is to allow them to fold in on each other during motion, rather than have a single edge which will act like an elastic band and create a 'pinch' in the middle of the bend.
Before moving on, it made sense to fully test the rigging of the hand (After all, it would be a waste of time to build unusable hands, only to discover so after the model was finished!). The bones were dutifully added to the hand, and were given the simple task of bending the fingers slightly. So far so good.
It was at this time I also started to get to grips with the 'Envelope' tool. After you use the 'Skin' modifier to attach bones, you can alter the area of effect (AoE) of each bone with the 'Edit Envelopes' option. This allows you to select each bone, and see the radius and strength of its impact.
To cut a long process short: Using the handles located around it: Move the envelope 'cage' until the areas affected are the only ones you want them to. The AoE is denoted by the colour on the mesh. With red being strong influence and blue being minor. As a rule of thumb - You do not want to even see blue in any area you do not wish for the bone to move. Blue should only be seen on edges where it meets other bones (And the influence is thus divided between them)
These are some of the shapes pulled after correctly moving the envelopes around. It was at this point that the low number of finger-thumb segments became apparent. For the time being, however, it was passable and the bends relatively clean.
With the mesh completed, the final step was to weld it all to the initial frame. Luckily, the octagonal cylinder made the connections an easy process. Each corner of the octagon was linked with the corresponding edge of the shoulder joint. A quick application of the 'Weld' tool fused the work together.
And there's one arm all connected up to the body.
The next step was to connect the hand to the wrist. As with the shoulder joint, the hand needed to contain the same number of vertices as the wrist (8) to create the clean join. It took a bit of trial-and-error: But the above solution created an 8-sided hole to connect to the wrist.
And it was from here that the wrist was extruded and linked together (In the same fashion as the shoulder joint), and subsequently welded.
And here are the finished limbs! Note: This was created before I went to the lecture where we learnt how to create hands properly. It was during then that I incorporated the 3 segments into the fingers, and re-created the thumb from scratch in a more realistic location and with 2 segments.
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