Waterline is an add-on that automates the creation of water foam around land objects intersecting a water plane. It works by generating vertex colors at the intersection points, which are then utilized by a procedural shader node setup to render the foam and water. The tool includes controls for foam dispersion, offering linear and exponential falloff options, customizable falloff factors per face, and adjustable outward reach before the falloff begins.

Users can apply the effect to multiple objects simultaneously using an eyedropper tool to select new landmasses and a reload function to update the scene. The generated node tree is fully organized and customizable, allowing adjustments to displacement, water colors, or the integration of custom foam textures.