From Filter Forge Wiki
Sometimes referred to as circular or spherical gradient.
...as the name suggests, makes a radial transition from the center to the periphery.
- Frame technique
- Tiles technique (when no single gradient/odd tiling needed)
- Odd-tiling techniques: Tiles+offsets AND Tiles+kaleidoskope
- Radial Sawtooth
- Radial Triangular (>Groovy!)
- Ripple Gradient (gaussian) (>Rain Ripples)