--- a/pkg/octree/vertex.go	Sat Sep 22 21:58:15 2018 +0200
+++ b/pkg/octree/vertex.go	Sat Sep 22 22:14:31 2018 +0200
@@ -154,7 +154,20 @@
 	return points
 }
 
-func (v *Vertex) read(r io.Reader) error {
+func (v *Vertex) Write(w io.Writer) error {
+	if err := binary.Write(
+		w, binary.LittleEndian, math.Float64bits(v.X)); err != nil {
+		return err
+	}
+	if err := binary.Write(
+		w, binary.LittleEndian, math.Float64bits(v.Y)); err != nil {
+		return err
+	}
+	return binary.Write(
+		w, binary.LittleEndian, math.Float64bits(v.Z))
+}
+
+func (v *Vertex) Read(r io.Reader) error {
 	var buf [8]byte
 	b := buf[:]
 	if _, err := io.ReadFull(r, b); err != nil {