Displacement texture map from JSplacement (left). Roll over image to view without displacement (right).
Displacement maps can be an excellent tool for adding surface detail that would take far too long using regular modeling methods. Displacement mapping differs from bump mapping in that it alters the geometry, and therefore will have a correct silhouette, and self-shadowing effects. Depending on the type of input, the displacement can occur in two ways: Float, RGB & RGBA inputs will displace along the normal while a vector input will displace along the vector.
The example above shows how a simple plane, with the addition of a displacement map, can produce an interesting looking simple scene.
You should ensure that your base mesh geometry has a sufficient number of polygons otherwise subtle differences can occur between the displaced low-resolution geometry and the high-resolution mesh from which it was generated.
Make sure that you use a 32-bit or 16-bit floating-point format to store your image, and not an integer format. An integer format will not work correctly. This is because integer formats do not support negative pixel values, which are used by floating-point displacement maps.
SItoA follows the standard Softimage workflow. You can connect any shader to the Displacement slot of the material.
The settings are driven by the Arnold Parameters property, so they belong to the mesh owning the property, and not to the displacement shader (which could be shared between several objects).