Connecting
and animating bones is one of the fundamental skills
required for making computer-generated animation. This
tutorial will how to do it and in spoonodelic style,
nonetheless.
The following tutorial works best
if you have a character that you have created and would
now like to animate. If you don't have a character,
the following 3DSMax file will provide you with something
to practice on. Please right click and Save As... this
link. This tutorial will go through the motions of
applying a simple IK Bone Setup and key frame animation.
Part One: Laying Down The Bones
Creating bones is a fairly simple
process, however, it is important to remember that
you can only create things on the home Grid. If you
attempt to create bones from the perspective viewport
without a Grid directly behind your character (or limb),
then the bones will be placed in areas you did not
think they would end up.
 Go
to the Command Panel>Create Tab>Systems and choose
Bones.
 Select
the display window that displays your limb and the
grid directly behind it. The following uses the Left
Viewport as a correct choice, and the Perspective as
the wrong choice.
 Click
and drag for each bone you want to create. This is
a fairly simplistic IK chain and will only require
four bones, for the hip, knee, ankle, and toes. Right-click
to end the chain.
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Part Two: Creating the IK Chain
 If
you try moving any of the bones, they will swivel from
the bone above it and the bones below will remain locked.
However, 3DSMax will do a lot of the work necessary
to constrain the bones to bend more naturally. Select
the bone between the toe and the ankle so that it is
highlighted.
 Select
the Animation>IK Solvers>HI Solver from the top
menu (6th from the right)
Before continuing, make sure that the mesh editing
selection tools are unselected. Just as the image above
shows that the vertices are chosen (in yellow), they
must be clicked again to shut it off (and removing
the yellow highlight.)
 Complete
the creation of the IK Chain by selecting the top most
bone.
 Complete
the creation of the IK Chain by selecting the top most
bone.
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Part Three: Skinning and Envelopes
The final portion of this animation
will skin the bones to the limb so that when you move
the cross-hair, the leg will move in the same way.
However, even though it should work 'out-of-the-box'
it never does and some tweaking will need to take place.
This is where Envelopes will come in.
 Select
the limb and then select Modify on the Command Panel.
 Click
the Modifier List and scroll down to the Skin option.
 In
the Parameters Rollout click the Add Bone and choose
the all the bones and the IK Chain. Click the Select
button when done.
Try moving the IK Chain (the blue
cross) now. The limb will probably move, but there
is something obviously wrong!
 Leave
the leg out of position so that you can see the stretching.
 Select
the limb once again and select Modify and then Edit
Envelopes
 Select
any of the bones and it will provide you a highlighted
area of the leg. These highlighted areas are envelopes
that control how much strength and control each bone
has on a limb. Wherever two envelopes overlap, a bending
will occur that is much softer and create the movement
expected at a joint in the body.
 Both
ends of each Envelope has handles. By adjusting the
coverage of these handles the bones will highlight
vertices with red, blue, and yellow colours. The red
is unyielding, yellow is a shared control between two
Envelopes, and blue shows minimal control.
 The
final result will allow your limb a normal movement
without any stretching or abnormalities. The bones
can be taken further by examining the Skin modifier
properties. By selecting Skin so that it is highlighted,
gizmo's can be setup for muscle and joint movement.
Imagine having the muscle bulge when flexed! Below
is what it should look like.
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