Path 
Template options
that compute closest path analytics, similar to the Distance
tools in ESRI's Spatial Analyst toolset. The transform provides
three basic Path types.
Each of those can compute results in three different Output
types, providing a total of nine
different combinations of Path
type and Output
type.
The Path transform should
be launched with the focus on an image layer in a map that also
contains a vector drawing layer that provides points for starting
locations. Points used in path computations can be restricted
to only those selected, using the Start
from selection only check box. The Path
transform allows a choice of Channel
to use in multichannel images.
Path type options:
 cost  Measure
distance through a lowest cost pixeltopixel
route, taking the value of each pixel as its cost, which might
not be direct, from each pixel to the closest point.
Avoids
pixels with NULL values. Checking the Use equal
costs box
(the default) uses the same cost for all pixels. The
overall length of the path is thus the cost of the path, with
the shortest pixeltopixel path being the least cost. Unchecking
the Use
equal costs box
counts the value of each pixel as the cost of that pixel,
and adds up the costs of pixels that the path goes through
to get the total cost of the path.
 cost for slope 
First calculate slopes for the raster,
and then compute lowestcost path distances using the slope for each
pixel where going downhill on a slope has lower cost than
going uphill.
 Euclidean  Measure
distance by simple, straight line, Euclidean distance
from each pixel to the closest
point. When the Use barriers box is checked, Euclidean templates will find
the shortest route using straight line segments which avoids
NULL pixels, called barriers, .
Output type options:
 direction  Report
the direction from
the pixel to the closest point.
 distance  Report
the distance from
the pixel to the closest point.
 value  (Formerly
known as Source Z value)
Fill each pixel with the same value, either taken from a field
value for the closest point, or with a sequential value.
Value options:
 (sequential values)
 Assign a sequential integer value (zero based counting)
to pixels closest to each point. If there are three
points, all pixels closest to the first point will be assigned
the value 0, those
pixels closest to the next point will be assigned a value
of 1, and those pixels
closest to the third point will be assigned a value of 2.
 <choose a field>
 Choose a field from which the value will be assigned to
all pixels associated with that point as a closest point.
Parameters for cost for slope:
 Min slope, Max slope
 Allowed minimum and maximum slopes in degrees. The
path will be routed around any pixels that have a slope value
less than the minimum slope or greater than the maximum slope.
The slope of a given pixel can be interpreted as a negative
slope or a positive slope depending on the direction we are
travelling. The
default values of 90 and 90 mean
to use pixels with all slopes. A more realistic scenario
is not to walk off a cliff (90) or to attempt to scale a
cliff (90). We can specify the minimum and maximum
slopes acceptable, such as not descending by any slopes steeper
than 30 degrees, or ascending by any slopes greater than
30 degrees.
 Min slope cost, Max slope cost  The cost
of a pixel in the path, based on the slope of the pixel and
the Min cost and Max cost values. The Min
slope cost value is the cost for pixels that have the
specified Min slope value of slope. The Max
slope cost value is the cost for pixels that have the
specified Max slope value of slope. The costs
of all other pixels are interpolated, based on their slopes,
between the Min slope cost and Max slope cost values.
The
default value of 0 for Min
slope cost in most cases will be replaced by 1,
so that all pixels have at least some cost. The
default value of 2 for Max
slope cost in most cases will be replaced by a larger
number, such as 100,
to allow for a greater range of values between minimum and
maximum costs.
Flat
Cost  The per pixel cost
of a path over flat, that is, zero slope, terrain. It
makes sense to make this about halfway between the Min
cost and Max cost values.
Reverse path  Paths in cost for slope operations
are computed by default from each pixel in the raster to the
source point. Checking the Reverse
path box switches directionality to compute paths
from source points to each raster pixel in their domain. The
direction matters because a downward slope path is shorter,
that is, lower cost, than the reverse upward path.
Launch the template by choosing
a Tile field and then doubleclicking
the Path
template. When the template launches we can specify options.
See the Raster
Paths topic for a detailed discussion and examples.
