The Waves tool allows you to add both horizontal and vertical waves to an image. Wavelength and amplitude can be independently set in both directions.
Like other distortion tools in the program, five options are provided for dealing with off-canvas pixels (clamp, erase, ignore, reflect, wrap). A dedicated Quality option uses bilinear interpolation to further improve the quality of the final image.
Finally, like all PhotoDemon tools, a dedicated command bar allows you to save and load custom presets, randomize parameters, and reset to default values. Last-used settings are automatically saved and restored, and all changes provide a real-time preview (no click or mouse button release required).