[GRASS-user] v.to.rast question

Hi all,

I was wondering if anyone could enlighten me about how exactly the v.to.rast function works. I would like to turn a vector layer of polygons into a raster layer. Basically, my layer shows where a species occurs (the value for the areas where they occur is 1). When I transform this vector into a raster file, how does v.to.rast decide what raster cell becomes 1 versus which becomes a 0? Does it depend on what percentage of the raster cell is covered by the polygon, or does the cell get a 1 assigned to it as soon as the polygon transects it at all?

Thank you for any help given!

~ Anke