The type buttons can choose in what mode the displace tool operates. The Radial mode uses the map image that refracts each pixel out from the center, while X/Y mode provides control over the amount of displacement along each axis individually.

Note that there is one set of refraction controls while in Radial mode, and two sets in XY mode, one for each of the X and Y channels.

The center control defines the point from which pixels are displaced towards or away from.

This array of buttons controls which Channel from the foreground image is used to displace the image. Select from Red, Green, Blue, Alpha or Luminance channels. In XY mode, this control appears twice, once for the X displacement and once for the Y displacement.

Controls the strength of the refraction. Higher values cause stronger or more pronounced refraction.

Two separate sliders appear to control the Refraction strength along the X and Y axes separately. Otherwise, this is exactly like refraction strength.

This controls the intensity or strength of the simulated light, causing bright and dim areas to form according to the contour of the refraction image. Higher values cause the bright and dim areas to be more pronounced.

This sets the angle of the simulated light source.

This widens the displacement effect and takes the edge off the refraction map. Higher values cause the ridges or edges spread out.

Select the channel from the refraction image that will be used as the simulated light source. Select from Color, Red, Green, Blue, Alpha or Luminance channels.