volume.range is undefined
here is a part from the code :
var sliceXController = volumegui.add(volume, 'indexX', 0,
volume.range[0] - 1);
var sliceYController = volumegui.add(volume, 'indexY', 0,
volume.range[1] - 1);
var sliceZController = volumegui.add(volume, 'indexZ', 0,
volume.range[2] - 1);
volumegui.open();
and here is the full code from lesson13 : http://jsfiddle.net/gh/get/toolkit/edge/xtk/lessons/tree/master/13/#run
what should i do now and thanks a lot