Hi people,
It was expected for a long time, so here is it : the brand new LineSystem.
This allow you to create a single mesh with as many lines you want. Just pass an array populated with lines, each line being an array of successive Vector3.
var nbLines = 30;
var nbPoints = 100;
var lines = [];
for (var l = 0; l < nbLines; l++) {
var points = [];
for (var p = 0; p < nbPoints; p++) {
points.push(new BABYLON.Vector3(p - nbPoints/2, Math.sin(p), l - nbLines/2));