displacement maps
 

the prob is that i want to add some cracks to a house with a displacement maps on polygons...i dunno where i do things wrong. the disp. map is all white black and grey...i blurred the map in photoshop.when i aplyed it to the house i used approximation editor and set it to highest quality.The geometry is 1 peace....and even doing all that gave me the effect of each wall going in its own way in space when rendered....the walls are completely detached
Give an advice!!!

emergency!!!

Can you post a render of the house and maybe the image you're using as the displacement? I sounds a though you might have values too high and/or you're mapping to the whole hose vice board by board.