9.5.2

862 • CHAPTER 18
THE SHADERS • 863
Gradient
The Gradient shader allows you to create gradients of many different types in 2D or 3D space.
Using gradients
To access additional gradient parameters, click the triangle next to the gradient.
The knots or handles below the gradient are used to set the color and position of colors in the gradient.
To add a knot, click in an empty area below the gradient and a knot of the color at that position will
be added. To remove a knot, drag and drop it away from the gradient. To change the color of a knot,
double-click it and use the system color chooser that opens to pick the desired color. The diamond
shapes on the gradient are bias handles and these pull the interpolation of the color knots from side
to side for more control over how the gradient changes.
Interpolation
Cubic Knots
Interpolates the knots with a CatMull - Rom interpolation while using the bias handles to offset the
interpolated value (good for several knots).
Cubic Bias
Uses a Bezier interpolation algorithm to interpolate between the knot previous to the sample point, a
weighted bias to the left, a weighted bias to the right, and the knot to the right of the sample position
(good for few knots and accurate control).