Heads and helmets
Helmets and alternative heads use the same construction. The skinmesh has only the head faces, but there is a complete set of bones, which must exactly match those of the base figure which is to wear the helmet (or head). If there is any discrepancy the helmet will not "fit". The simplest way to do this is to start with the full figure and delete all non-head vertices from the skinmesh. This leaves the head vertex weighting unchanged. Then delete the faces covered by the helmet.
In order for the new head to join to the figure's mesh the vertices at the neck have to be defined on both the base figure and the head. This is done using the Neck Stitching tool in Siege MAX. Figures that do not change heads or helmets do not need a stitchable neck, so most monsters do not have these.
In addition to the boundary vertices, the faces that are deleted or
added are marked as "head" faces using the Aspect Tool Kit (Sub Mesh Tools).
The same mechanism handles boots and gloves, so there are selections for
feet and hands too. On a replacement head (or gloves, boots) nothing gets
replaced, so make sure these are all set to zero faces.
The faces of the helmet head also need to be assigned to two separate materials. Material 1 is the skin, and material 2 is the helmet. A replacement head will be all Material 1.
The vertices of the head must also be weighted onto the bones, so that
they will move when the bones are animated. If the head is rigid, as with
a helmet mesh, just select all the vertices of the helmet and assign a
weight of 1.0 for the Bip01_head bone.
If parts of the hair are movable, as with Lara's ponytail, paint weights
appropriately for the ponytail or similar bones. Remember that if you need
extra bones, they have to be added to all meshes used by
the character, including all other helmets, heads, gloves, boots and armor
variants. There are about 70 meshes involved, and you also have to remake
all the animations to determine how the new bones move!!
This example is from the first Lara Croft mod (which was just a new head
and skin textures) so the ponytail bones are the original farmgirl ones.
For Lara Mk II, I moved the bones to fit inside the ponytail, as well as
adding some new ones elsewhere in the body mesh.
