thanx for feedback, BGHArt : your observation are really important for me to make a good model... blurring texture will be fixed at the end of work, in the ruins i've some window-arches (not in image uploaded)... the only problem are square stones, in my model i've 2 type : one with many faces and with roundness of edges, other with only 12 faces (a cube) without realistic noised apparence... the proble in other words are the amount of final polygons : 5000 cube-stones * 12 faces = 60.000 polygons VS 5000 rounded-stones * about 1000 faces = 5.000.000 polygons... i think too much for a smart use of model...