The Advanced Gradient Controller panel is broken up into three main sections:

Sample

This pop-up menu allows the user to choose between ball or cube preview geometry

Size

This input field allows the user to determine the size of the geometry in the Preview window. By setting this value to the approximate size of the target surface the user can get a more accurate representation of how the gradient will appear. This input field is for preview purposes only. The value set here does not affect gradient size on the target surface.

Checkers

When selected this button displays a checkerboard pattern as the background for the sample window. This is particulary useful for view dark gradients and gradients with transparency. This feature is turned off by default and a black background is displayed in the sample window.

Position

These three input fields allow the user to move the sample geometry through the gradient. The input fields control the velocity along X, Y and Z respectively. These input fields are for preview purposes only. Values set here do not affect gradient placement on the target surface.

Preview window

This window displays the current AGC settings on a sphere or a cube.