Displacement Maps

I have been wondering something. What is the difference between a displacement map and a bump map? Also what is the diference between using the Nor button located in the materials window and the Disp? Also where would i find a good tutorial for learning how to effectively use these features? Thank you for any help?:confused:

cermir,

In a nutshell - bmp mapping gives the illusion of surface roughness which loses itโ€™s appeal at edges. Displacement actually modifies the geometry prior to rendering (moves vetices and can cast shadows). Generally speaking, if you use displacement, you will need a finer mesh. Also, keep in mind that when using displacement in the Map To panel, even if you donโ€™t map to Nor, the Nor slider still has an effect on the results.

More info here and here

Thank you for the links.