OK before we can start painting our texture, there are a few things we need to know about working in 3D (isn't that always the way?). By now, if you have done the first part of my tutorial, you will be familiar with the three elements that make up a 3D model in 3DS Max. These are Vertices, Edges and Faces. But there is a forth element, which we haven't talked about yet! This is the 'mapping coordinates'. What are these mysterious things? Well putting it in as simple terms as I can, mapping coordinates determine what position a face will lie within a texture map. Initially a face does not have any mapping coordinates, you must apply them, thus telling 3DS Max where you'd like the face to lie on a texture map that you may provide.
There are various ways of applying mapping coordinates in 3DS Max, the simplest being during the creation of a primitive object by selecting the "Apply Mapping Coordinates" option within the object creation dialog. This automatically places mapping coordinates on all the primitives faces. You can edit these later, if you want. This is quite handy, but character models generally are more complex than a simple primitive, so a more gutsy manual method of applying mapping coordinates is needed.
The first step to manually applying mapping coordinates, to our body model, is to select the faces that you'd like to apply coordinates too. You do this from an "Editable Mesh" using "Sub-Object Face" with "Ignore Backfacing" ON.
Select all the front faces on the full body model.
Arc rotating around the model, in the "Perspective" viewport, so you can see that indeed the front faces are all that is selected.
In the UVW Map Parameters roll up that appears, Select the "Planar" type of coordinates, which keeps the coordinates to a flat plane. It is easier to work with many flat planes (or as close to a plane as possible) within the model, rather than try and map the whole model at once.
The whole front of our model is close enough to a flat plane for now. We can work with more detail later.
Once the Planar coordinates are applied, a rectangle called a Gizmo appears around the selected faces, which represents the boundary of the texture map. Make UVW Map a Sub-Object and you will see the Gizmo go from orange to mostly yellow. Ensure the green side of the Gizmo is on the right and the side with the small line sticking out is at the top, otherwise you are looking at the back and/or upside down, which can give undesirable results later on.
With the UVW Map Gizmo in Sub-Object mode you can move, rotate or scale the coordinates in any direction, repositioning the selected faces within the texture map.
We will scale the coordinates up and move them so the selected faces are moved to the top left corner of the map.
There is reason to our madness which will become obvious soon.