TYPE: SOP
TITLE: Inflate SOP

Inflate deforms the points in the first input to make room for the
inflation tool.  The first input is inflated by taking a number of
inflation points.  From each inflation point, the surrounding geometry
is moved away from the inflation point so as to account for the shape
of the inflation tool.  The inflation points do not have to be inside
the tool geometry, but if they are outside, the tool geometry will be
implicitly expanded to contain the inflation points.

If two inputs are given, the second input is the inflation tool.  If
three are given, the third input is the rest position of the
inflation tool.  If a rest position is given, the rest inflation
points are used to determine sidedness of the inflation points.  If
the current inflation point is on the other side of the geometry
compared to the corresponding rest inflation point, it will be moved
back to lie within the geometry.  The Min Surf Distance controls this
behaviour.

For each point to inflate, one single inflation point is calculated
and the inflation is done with respect to that point.  Instead of, or
in addition to, inflation points, inflation primitives may be
specified.  Closed polygons will be assumed convex and planar, and the
inflation point will be the minimum point to the polygon.  Open polylines
will create an inflation point for the minimum point on each line
segment.  The set of inflation points found will then be interpolated.
Those within Center Overlap of the closest will be blended according
to the Blend Exponent.

Parameters:

    Group		- Points to be affected by the inflation.
    Tool Group		- The primitives in the inflation tool that
		    	  will be used as the tool geometry.
    Center Group	- The points in the inflation tool that will
			  be used as inflation points.
    Center Overlap	- Controls the width of the band where
		      	  inflation points will interact.
    Blend Exponent	- The fall off rate for the Center Overlap.
    Min Surf Distance   - This is the closest which the current
			  inflation points can get to the first inputs
			  surface, as measured along a line between
			  the rest inflation point and the current
			  inflation point.  If disabled, no clipping
			  is done.
    Tightness		- This controls the falloff of the inflation.
			  A value of 3 will approximately preserve
			  volume.  A value of 2 will preserve area if
			  the inflation is occurring inside a plane.
    Inflate to Farthest - Normally the inflation stops when it hits
			  the first outgoing surface in the tool
			  geometry.  This option will cause it to
			  inflate using the farthest intersection.
			  This will produce bad results if the geometry
			  is not convex with respect to the inflation
			  point, but can allow the use of multiple
			  overlapped geometry.
    Maximum Inflation Distance - This can be used to minimize the bad
			  effects of Inflate to Farthest when working
			  with non-convex geometry.  It specifies the
			  maximum distance which can be considerd a
			  valid inflation - any geometry farther than
			  that is ignored.

See Also: Bulge
