We have our maps laid out using hydrography maps from NOAA. We had to run the graphics through several steps to create the water feature raster. I have a process that pulls in that raster, sets a start and end point, and computes a Polyline which provides my distance between points. But we were getting strange results that had to be figured out. I added the cost array to the map and it is a regular, circular growth from the target point out. In a few places it appears to follow rivers but mostly it ignores the existance of land.
It reports values as being between 0 and 17xx. I'm concerned about the cost value of 0 as I though no raster can have a value of 0. So is this because I need to convert 0 to NoData? And if that is the case how do I do the conversion?