A displacement map is a 2D image that records height information for points on the model as gray scale information. Displacement mapping allows a model to represent visual detail not modeled or sculpted into the original mesh and can be used as a method for transferring sculpted detail from one model to another.
Displacement maps differ from normal maps in that they work well to represent detail on simplified meshes when the model’s silhouette detail needs to be apparent to the viewer. Displacement maps are widely supported where the 3D model is rendered using software (for example: to produce images for film and print) and in circumstances where normal/bump maps don’t provide enough realism.
When the displacement map is applied to a low resolution model and rendered, the faces are often subdivided further and offset (displaced) from their original positions based on the gray pixel height values in the image map. The rendered result produces a detailed effect very similar to the high resolution surface in Mudbox from which the displacement map was extracted.
