Add vertices to lines
I am using QGis 1.8.0 I would like to densify a polilyne according to a particular length of segment (ex. 200 m). I know it is possible with other Gis. Is it possible in QGis?
Yes it is possible. Densify is located under the vector menu.
I assume what you mean by densify is effectively a buffer, where the line thickness is proportional to a function of the line length.
This can be achieved using a small amount of scripting. I am unable to write the script at present as I have no access to QGIS, however the pseudocode will be along the lines of: