TYPE: SOP
TITLE: BlendShapes SOP

BlendShapes computes a 3D metamorphosis between shapes with the same topology.
It can blend between its inputs using average weights of each input's
respective channel. It interpolates point colors and/or texture co-ordinates
between shapes.

Parameters:

    Group           - Points or primitives in the first input to be blended.
    Differencing    - Exaggerates morphs between objects where values above 
		      1 or less than 0 will result in over-scaled shapes.
    Selection Index - Specifies which input to use when generating the
		      cooked selection.                       /selectionidx
    Blend Position  - Enables blending of point positions.
    Blend Colors    - Enables blending of point colors and alphas.
    Blend Normals   - Enables blending of point normals.
    Blend Texture   - Enables blending of texture coordinates.
    Assume Only Coordinate Changes In Input - This accelerates the blend
			 speed when there exists an animated input
			 that only has changing point positions.
			 Unpredictable results will occur with this
			 enabled if attributes or topology changes.
    Assume Morph Network Setup - This accelerates the blend speed when the
			 inputs have the particular wiring the Morph tool
			 creates.  The blend speed can be accelerated when
			 the following three properties are true: 1. all
			 of the inputs to the BlendShapes SOP after the first
			 input are Edit SOPs  2. the first input to the
			 BlendShapes SOP is the same as the first input to all
			 of the Edit SOPs  3. if the Edit SOPs have a second
			 input, they must all be the same
    Blends          - Controls contribution of geometry inputs.
		      /shape0 /shape1 /shape2 /...

See also: Sequence Blend(sblend)
