3ds Max 2012 Bible - Kelly L. Murdock [362]
FIGURE 33.23
The lion toy face cluster is displayed after moving and pinning vertices.
If you find that moving the vertices isn't helping, you can always click the Reset Peel button to start over. This automatically removes all pins and resets the cluster layout.
Using Pelt mapping
Pelts remind me of early turn-of-the-century explorers and trappers who captured and skinned critters such as foxes and wolves and preserved their fur pelts on a circular rack. These furs were valuable commodities that could be traded for whatever the trapper needed. The market for such furs has diminished significantly, but the concept works well for the virtual world as a mapping method for applying textures to 3D objects.
Another automatic mapping method available in the Peel rollout of the Command Panel is Pelt mapping. Consider mapping a complex mesh like the human head. Using traditional mapping methods, you would divide the head into sections based on planar projections like those in Figure 33.24. The UVs for this head include planar views of the front and back of the head. These provide good UV coordinates for features that are straight on with the projection, but the ears and the sides of the nose are all wrong using this method. You could divide the mesh into more projections, including one for each side of the head and for under the chin, but then you need to deal with matching the seams between the different parts, which is a tough challenge.
FIGURE 33.24
Planar mapping isn't a good solution for a complex head mesh.
Pelt mapping overcomes these difficulties by allowing the user to define the seams for the mesh. These seams can be located along material boundaries or along mesh borders. The vertices along these defined seams are then positioned around the edges of a circle called the Stretcher and pulled until the mesh UVs are pulled flat. This results in clearly displaying and flattening all the UVs for the selected part, allowing you to easily paint and apply a texture map.
After the seams are defined, select all the faces that are to be mapped and click the Pelt button in the Peel rollout in the Command Panel. This opens the Edit UVW window along with the Pelt Map panel, shown in Figure 33.25.
FIGURE 33.25
The Pelt Map dialog box includes commands for stretching the pelt mapping.
The Edit UVWs window opens with the front projection displayed, and all seam points are positioned in a circle around the selected faces, as shown in Figure 33.26. The circle of seam points is called the Stretcher, and the lines connecting the Stretcher points to the selected faces are springs.
FIGURE 33.26
Pelt mapping positions all seam points in a circle around the selected faces.
The Start Pelt button causes the springs to pull at the selected UV faces, causing them to stretch toward the Stretcher using the defined spring properties. The stretching continues until you click the Stop Pelt button. If you enable the Show Local Distortion option, all UVs that are severely distorted appear in red. Figure 33.27 shows the UV faces after being stretched.
FIGURE 33.27
After being stretched, the UV faces are lined up quite well.
In the Pelt Options rollout are settings for altering the stretcher locations. The Select Stretcher and Select Pelt UVs buttons let you select and manipulate both the selected faces and the Stretcher points. You also can straighten and mirror the stretcher or have the UVs snap to seams. The Snap to Seams button is especially helpful if you have an object like a hand that curves back in on itself. If you Snap to Seams before stretching, the stretcher assumes the shape of the seams.
If you get confused, the Reset Stretcher button returns the mapping to its starting positions. The Relax