Function nannou::geom::tri::vertices_from_iter

Important traits for VerticesFromIter<I, V>

impl<I, V> Iterator for VerticesFromIter<I, V> where
    I: Iterator<Item = Tri<V>>,
    V: Vertex,  type Item = V;

pub fn vertices_from_iter<I, V>(tris: I) -> VerticesFromIter<I::IntoIter, V> where
    I: IntoIterator<Item = Tri<V>>, 

Produce an iterator that flattens the given iterator yielding triangles into its vertices.