The technique for modeling a human head was excerpted from Peter Ratner's book 3-D Human Modeling and Animation. In this example, we will model a head using vertical open splines to outline the front and side contours of the head, add additional splines to define the full shape of the head, and then surface these splines using Modeler's Loft tool to form the mesh that encompasses the head. This technique can also be used to model the torso or most organic shapes.

Step 1 - Using Templates To Create The Outline Of The Head

The front and side views of the head shown in Fig. 1 will be used as templates to define the contour of the front and the side of the head. To start, since it is the most complex part, use the side view in Fig. 1 of the head to define the contour of the front of the head. This will be the spline that will be duplicated to form the rest of the face. This also insures that all the splines used in defining the shape of the head will have the same number of vertices.

Fig. 1 - Face templates

Start at the crown of the skull and place enough vertices along the contours of the front part of the face and neck to to make the spline fit the contour accurately as shown in Fig 2.

Duplicate the newly created spline, reshape the spline to fit the contour of the back of the head as shown in Fig 3. When duplicating splines, set a rotation point at the top and rotate the duplicate around that point.

Fig. 2 - Front Outline	Fig. 3 - Back Outlines	Fig. 4 - Side Outline

Use the front view of the head in Fig. 1 to define the left side of the head. Duplicate the newest spline, reshape the spline to fit the contour of the right side of the head as shown in Fig. 4. Since the face is symmetrical, only one set of splines is needed for the sides of the face. The other half will be made up of duplicates that have been mirrored.

The three splines shown in figures 2, 3, and 4 are shown in Fig. 5 as they appear in the top, front, and right side views.

Fig. 5 - Top, front, and right side views of the three splines

The next step is to add splines between the existing ones to start shaping the rest of the head. You can now add an extra spline between the back and sides ones as shown in Fig. 6. Another spline can be added between the side and front splines. Test the shape of the splines by skinning (lofting in Modeleer) part of the head. If you see places that need fixing, shape the mesh and then bend the splines to follow the form of the fixed mesh.

Fig. 6 - Top, front, and right side views of the three splines

The next stage of the face is shown in Fig. 7. Three extra splines are added to the front of the face. These will be used to refine the features such as the eye, nose mouth areas. Test the new splines by skinning them. Reshape the mesh if you need to and curve the splines along the fixed outlines of the mesh.

Fig. 7 - Top, front, and right side views of the three splines

Skin all the splines for half of the face to check for any flaws. Fix the mesh if needed and shape the original splines along the mesh's new structure. Duplicate all the splines and mirror them for the other side of the face as shown in Fig. 8. Organize the grouping of the splines in the group table so that they follow a logical order such as starting from the back, proceeding to the front and ending with the back. Make the extra front and back splines invisible or delete them.

Fig. 8 - Top, front, and right side views of the three splines

Select every spline in a logical order. You could start with the back spline, work around to the front one and then finish with the back one that you started with. Perform a skinning operation on the splines. The process should make a complete sweep around the head creating a spline-meshed shape as shown in Fig. 9.

Fig. 9 - Top, front, and right side views of the three splines

If you have been testing out the mesh previous to the final skinning, you will not have to reshape the mesh except for a few minor adjustments. If you would like to add extra detail such as nostrils, you could insert extra splines in those places. Again, as mentioned before, only add splines if it is crucial. Too many splines will make the face too complicated to model. Insert an extra horizontal spline in the middle of the lips and pull the resulting vertices at the lips back. Curve these splines to shape the hollow of the mouth.