I have in my possession four sets of shapefiles:
1. Locations (points), around 1000
2. Roads (lines), each road has a speed attribute
3. Terrain (polygons), each zone also has a speed attribute
4. Rivers (lines), each river has a crossing delay time attribute
How can I construct a Voronoi diagram for my location using travel time as a distance metric? I could have used pgRouting if I had roads only, but I am not sure how to approach different off-road terrain and rivers. I'm willing to code this, but I've spent enough time trying to come up with an algorithm, but to no avail.
My current plan is to dump it all into a sufficiently large raster and create 1000 distance maps out of it, then use them to calculate the Voronoi cells, but I have a suspicion that a sufficiently large raster will take too long to process. Is there a better vector-based algorithm?