Hi Abesh,
think I have cracked this. You need to bind the property as follows.
dataset1 = new sap.viz.ui5.data.FlattenedDataset();
var dimObject = new sap.viz.ui5.data.DimensionDefinition();
dimObject.setAxis(1);
dimObject.setName("Product");
dimObject.bindProperty("value","Material"); /* Use this instead of setValue method */
dataset1.addDimension(dimObject);
var measObject = new sap.viz.ui5.data.MeasureDefinition();
measObject.setName("Quantity");
measObject.bindProperty("value","PercQuantity"); /* Use this instead of setValue method */
dataset1.addMeasure(measObject);
dataset1.bindData("/Rowset/Row", "");
Cheers
Graham Robbo