[Bsod-mentors] proposal for armature documentation

[rob c]

I'd like to propose that I write a complete documentation of armatures
as they are in blender cvs for the BSoD. In this proposal, I will
refer to a single male user, instead of saying things such as "they",
or "them", or "he/she"... or "it". =D.

I would assume the reader has already gone through the blender UI
introduction and understands the basics of the UI, such as 3D space
navigation, object creation, deletion, and window manipulation.

Overview:

The goal of my documentation would be to take a person who has
basically no understanding of armatures at all, and teach him
everything he needs to know about them to build professional quality
rigs that behave exactly as they are expected to. Animation is outside
the scope of my documentation. To lump animation and character setup
together, is to skip a tremendous amount of information that would
greatly improve the quality of the reader's character setups.
Character animation deserves it's own BSoD grant alone.

After I have covered all of the basics and all the armature features,
I'd like to take the user through a couple different rigging
scenarios: Spines, and Legs. The point of these scenarios is to get
the user thinking about the many, many ways with which constraint
systems can be used to create controls that will greatly simplify the
animation process.

Legs:
Human legs are pretty straight forward, it's the foot rig that a lot
of people put a good amount of thought into. I use the same foot rig
as demonstrated by Bassam in last year's blender conference, so I
would describe that design. Controlling the direction of the knee is
not too difficult, if one knows how to do it properly. Things can get
more interesting when you change the type of leg though. After having
the user build a rig for a human leg, I would have him build a rig for
a two-jointed, chicken-type leg.

Spines:
Spines will be a more lengthy topic. There are four designs I'd like
to present to the reader, starting with the most simplistic, and
ending with the most complicated.
1. Using a single B-Bone. Very simple, but b-bones elongate with
increasing bend angle.
2. Using a chain of bones that copy the local rotation of the root
bone, causing the rotation to propagate down the chain.
3. Using IK constraints on each bone of the spine to targets along the
length of a single bone that is rotated to induce spinal articulations
(this one is used in the robot shown in the pieces of work I've
submitted, only one bone is manipulated to create all of his various
torso positions, unless you consider his hips--a second bone--which
can be rotated or translated as well and the spine will still bend
naturally).
4. Using IK constraints on each bone of the spine, targeted to empties
that are parented to the vertices of a mesh that is deformed on a
curve, causing the spine to follow the curve. This is the design that
offers the animator the most options, since essentially any pattern of
movement can be generated on the curve and the spine will follow.
Rotations--or twisting, can also be done on the bones of the spine
while it continues to follow the curve.
www.exenex.com/wavez/twisty.jpg
www.exenex.com/wavez/twisty.avi

My Documentation in Abbreviated Form:

I would start with an introduction to armatures by having the reader
create one and I would make comparisons between it and other similar
objects, in that they both have an object center, an object mode and
an edit mode, and I would of course introduce the pose mode as the
extra mode that is needed to facilitate the animation process. Before
explaining how any of these modes work, I would continue the armature
introduction, with and explanation of why armatures are needed:
organic characters require a single mesh character model and thus, a
sub-mesh hierarchy is needed in order to give the character movement.
I'll try to keep this all in simple terms though.

>From there I would explain how to work with edit mode and I would have
the reader build hierarchies and then rotate the hierarchies in pose
mode.

Here I would introduce the various draw modes and all of the other fun
tools that are found in that same panel.

>From there I would transition to the methods with which blender
attaches meshes to armatures. I would start by explaining the two ways
to connect a mesh to an armature; modifier and parented relationship.
I will direct the user to use modifiers, and I'll explain that the
parented relationship is an old approach that lacks the new features
of modifiers. I would then cover weight maps, then envelopes, and then
their areas of overlap and use together.

To allow the user to move directly into character weight assignment, I
would supply a ginger bread man scene and have the reader build the
armature and weight the mesh to it.

I compile blender from CVS, so my documentation will be extremely current.

Here is some of my work:

Spider-Man:
http://blenderartists.org/forum/showthread.php?t=56833&highlight=spider-man
http://www.exenex.com/wavez/
Spider-Man is incomplete due to frustrations that I have with lattice
objects when being used in the way that I am trying to do.

Robot:
www.exenex.com/wavez/robot1.jpg
www.exenex.com/wavez/robot2.jpg
www.exenex.com/wavez/robot3.jpg

I have been working with blender since 2.32 or 2.33. I am now 21 and I
have been involved in computer graphics and games since I was 12.

Thank you for giving all of us this opportunity.
-Robert R. Christian