Attaching Al's Shoe Meshes to Sims2 Meshes
About the BodyChop Plugins
The Sims2 meshes use a "Skeleton", much like our human skeletons.
This skeleton is animated by the game to perform the various actions.
The vertices of the
Sim's "body" are connected to the Bones (or Joints) of this skeleton by vertex assignments - each vertex
will move in whatever way the bone it is assigned to moves.
But at places where the Sim's body will bend sharply, such as the knees, elbows,
where the leg meets the pelvis, and so on -
the parts close to this bend would move sharply,
creating a very obvious "crease" sort of look
which would give an overall sort of "blocky" look to the animations
as if you were bending the arms and legs of one of those plastic figures.
Maxis fixes this by allowing each vertex to actually be partially assigned
to up to 3 different "joints".
So, a vertex on the lower leg but close to the knee would be assigned
to the calf of course, but also with a secondary assignment to the thigh.
Now it will still mainly move as the calf bone does, but also it will be
influenced a bit by the position of the thigh - so the "bending" will look smoother,
it won't move up into the thigh sharply, but will have a more natural rounded
look where the bend is.
Our problem is that MilkShape doesn't allow for these secondary assignments.
The solution is Wes H's BodyChop plugins. When you import with this plugin,
you will see two mesh "groups" - the body group, as expected, plus a second
BODYMOD.1 group. Certain meshes (mainly nudes, underwear, and some swimsuits)
will also have a 3rd group for the "Pregnant" state of the mesh, but most meshes do
not carry a "Pregnant" state.
The first group is the "normal" body mesh, and has all the primary joint assignments.
The second group is the "fat" state of the Sim, and has all the secondary assignments.
Here I have hidden the "body" group, leaving only BODYMOD.1 showing.
I have selected the left_thigh joint, and clicked the [SelAssigned] button to show all the vertices that have a secondary assignment to the left thigh bone.
Notice that these include the ones by the knee as mentioned - but also notice that the ones in the center part of the skirt that are really closer to the right thigh also have a secondary assignment to the left thigh. So, as the Sim walks, her left and right legs will move away from each other, and so will the parts of the skirt assigned to them.
But, in the center, these vertices are also "influenced" by the opposite leg's motion, so they will not move quite as far, and will make a more natural looking bend
in the skirt rather than a sharp "crease"