Curve Gradient Layer
As you already guessed, a Curve Gradient is a gradient that follows a curve. One side of the curve will be filled with the color at the beginning of the current gradient (see the Gradient Editor Dialog), and the other side will be filled by the color at the end of the gradient. In other words, the gradient will fully cover your canvas (as the other gradients do), and you'll have to play with the Blend Method if you want to bind it to a specific shape.
There are two ways to display a gradient: the default one (fast), and an improved one that can remove any render artifacts you have with the first one. To switch from one method to the other, check/uncheck the Fast parameter from the Params Dialog.
Creating a Curve Gradient
There are several ways to create a gradient that follows a curve.
- With the Bline Tool, check "Gradient" in the Tool Options dialog. It will create a gradient that follows the curve you draw.
- In the Layer menu (from the Canvas Menu Caret or with a right click on a layer in the layers dialog), select Gradients > Curve Gradient. It will create a gradient with a default shape. On the Params Dialog, right click on Vertices, and select Convert > BLine, so you can edit the shape of the gradient.
- To make a Curve Gradient follow an existing shape, place the Curve Gradient layer above the layer containing the shape in the Layers Dialog. Select those two layers, then on the Params dialog, right-click on Vertices (greyed) and select Link.
- Alternately, to make a Curve Gradient follow an existing bline shape (outline, region, or other curve gradient), select the shape you want it to follow, right-click its Vertices parameter in the parameter dialog and chose Export from the menu. Type a name in the dialog that pops up. Then select the curve gradient layer where you want to use this exported shape. Open the Children dialog, find the shape you just exported and select it. Then right-click on the Vertices parameter of the Curve Gradient layer where you want to use the shape and select Connect from the menu.
Spreading the gradient
Your curve gradient is now created, but it may not look at all like a gradient. Instead it may looks like each side of the curve was filled with a solid color. That's because the width of the gradient is too small. Make sure that the Curve Gradient layer is selected, and in the Params Dialog, increase the Width value. Your gradient will appear.
An easier way to increase the gradient size is to use the Width ducks. In the Canvas Menu select View > Show/Hide Ducks > Show width ducks. The width ducks appear in purple on the canvas. Grab one of them to adjust the width. Each width duck can be adjusted independently.