[OSGeo-Discuss] Thoughts on how to use elevation in routing

[Bill Thoen]

Stephen Woodbridge wrote:
> Hi all,
>
> (This is cross posting from the pgrouting list, sorry for the dups.)
>
> I have preprocessed some shapefile data and added elevation 
> information in the Z value of the coordinates. I'm wondering how to 
> best utilize that in routes and would like any thoughts or ideas you 
> might be willing to share.
>
> The obvious answer is to wrap the elevation data into the cost values 
> as this is simple and straight forward and does not require code 
> changes. This brings me to what have other people done or thought 
> about doing in this regard?
Since you seem to enjoy large database problems, have you considered 
loading  the DEM data together with the roads and sample the viewshed 
every few km? You could then create an objective cost factor for 
"scenic," proportional to the amount of land visible, with some 
adjusting factor that distinguishes morphology, land cover, or other 
weighted factors from each sample point. Creating a scale of  "scenic" 
and "picturesque" as it goes form "ho-hum flatland" to "precipitous, 
brake-burning, wheel-gripping  adventurous" might be fun all by itself.

If you're looking for 3D ideas, there's a GIS  consulting company across 
the hall from me that specializes in 3D information, visualization and 
analysis, and I know they are working on web services to deliver the 
sort of data that an application like yours would consume. Their website 
is full of 3D imagery, articles and examples that you might want to 
check out for ideas or inspiration  There's a particularly good 
demonstration of using fog instead of shadow to create a visual 
representation of ridge lines, if your 're using those to determine a 
topographic index (see http://ctmap.com/serendipity/index.php).

*Bill Thoen*
GISnet - www.gisnet.com <http://www.gisnet.com/>
1401 Walnut St., Suite C
Boulder, CO 80302
303-786-9961 tel
303-443-4856 fax
bthoen at gisnet.com