Cost Distance

Finds the least cost path from one or more origin pixels to one or more destination points.

The key to this transform is the "Cost Distance" raster which contains pixels that each contain the "cost" to move from one pixel to another back to the origin pixel. This is an accumulated cost from one of the origin pixels to the pixel being examined. When the Cost Distance raster is created a "Direction" raster is also created that contains the directions that were traveled from the Origin. This raster can be used to create a final "Least Cost Path" from a destination point back to one of the origin pixels.

The Cost Distance transform can also take a "Cost Raster" that contains the cost to move across each pixel in the area. In other words, each pixel in the Cost Raster contains the price to move across that pixel. If we're building a trail, the cost would be the cost to build the trail over the pixel from left to righ or top to bottom of the pixel. Moving diagonally is a little more expensive and is handled within the transform. If the Cost Raster is not provided, a value of 1 is assumed.

An example would be if we wanted to create a trail from a road to a point of interest in a park. The road would be the origin and would be converted to a raster using "To Raster". The point of interest would be the destination point.

Content Tab

Settings Tab

Origin Layer: The layer containing a raster with the origin pixels.

Cost Distance(optional): An optoinal layer for costs to cross the pixels.

Origin Value: The value of the origin pixels. If the pixels for the road in the example above are 1, set this to 1.

Tolerance: A value of 0 will give the most precise answer. For large rasters, the tolerance and be increased to improve performance.

Cost Distance Raster: The output raster containing the cost to return to one of the origin pixels.

Direction Raster: The output raster with the directions from the origin to move with the least cost to each other pixel in the area.