vel.sample(interval)

Sample the underlying SVG element (it currently works only on paths - where it is most useful anyway). Return an array of objects of the form { x: Number, y: Number, distance: Number }. Each of these objects represent a point on the path. This basically creates a discrete representation of the path (which is possible a curve). The sampling interval defines the accuracy of the sampling. In other words, we travel from the beginning of the path to the end by interval distance (on the path, not between the resulting points) and collect the discrete points on the path. This is very useful in many situations. For example, SVG does not provide a built-in mechanism to find intersections between two paths. Using sampling, we can just generate bunch of points for each of the path and find the closest ones from each set.