TYPE: SOP
TITLE: UVPelt SOP

UVPelt assigns texture UV coordinates to the Source geometry for use in 
texture and bump mapping.  UVPelt operates very similar to how a tanner
creates a pelt.  Cuts are made to the geometry to produce a surface
topologically equivalent to a disc.  The boundaries of this surface are
connected to a frame and stretched out.

Any closed face can be used as a frame for the pelt.  A circle is used if
no frame is specified.  A hint polygon is used to specify which section of
the geometry to pelt after performing the cuts.  The boundary with an edge
closest to the hint polygon is the one connected to the frame.  The frame is
parameterized to the range [0, 1).  The boundary points are spaced around
the frame at distances in the frame's parameterization that are proportional
to the edge length with the neighbouring boundary point.

The effect of this operation is best visualized in the UV viewport.

UVPelt creates the UV texture attribute if it does not already exist.
The attribute class (Vertices or Points) is determined by the Target Type.
It is recommended that UVs be applied to vertices, since this allows fine
control on polygonal geometry and the ability to fix seams at the boundary
of a texture.

Note: UVPelt only operates on polygons.  Other geometry type such as Bezier
and NURBS surfaces can be converted to polygons using a Convert operation
prior to applying UVPelt.

Parameters:

    Group               - Edges to cuts.                          /group
    Target Type         - The attribute class (Verticies or Points) that
                          will receive the UV attributes.         /target
    Frame               - The primitive to use for the frame.     /frame
    Create Output Group - Indicates a primitive group should be created
                          for the polygons making up the the pelt.
			                                          /outputtoggle
    Output Group        - Name of the primitive group to create.  /outputgroup

    Iterations          - Specifies the number of iterations of the algorithm
			  for solving the UV positions.           /iters
    Boundary Springs    - The strength of the springs connecting the pelt
                          boundary to the frame.                  /k
    Stiffness Attribute - Specifies an attribute of the input geometry's
			  points that will be used to scale the strength of
			  the springs connected to the point.     /stiffness
    Hint Primitive      - The primitive specifying which section of the
                          geometry forms the pelt.                /hintprim

    U From              - The attribute of the frame used for the U
                          coordinate.                             /ufrom
    V From              - The attribute of the frame used for the V
                          coordinate.                             /vfrom
    Use Range           - Indicates the UV coordinates should be moved to the
                          ranges specified with U Range and V Range.
			                                          /userange
    U Range             - The location of the left and right edges,
                          respectively, of the texture            /urange
    V Range             - The location of the bottom and top edges,
                          respectively, of the texture            /vrange
    Orientation         - Specifies where on the frame to position the first
                          boundary point (the boundary point closest to the
			  hint polygon).                          /orientation
    Weight Attribute    - Specifies an attribute of the frame's points that
			  will guide the process of connecting boundary points
			  to the frame.                           /weight

See also: UVTexture(texture), UVUnwrap, UVProject
