Real-Time Flow Map Painting in Unreal Engine

This item introduces a real-time flow-map painting feature for Unreal Engine 5 that lets artists paint and save the movement direction and mask of a sky texture. The workflow is designed to reduce rep

Designate the sky’s movement with a brush

Real-Time Flow Map Painting in Unreal Engine covers a feature for directly painting the movement of sky textures within Unreal Engine 5. Its goal is to reduce the repetition visible along cloud edges and the distortion at the top of the sky in conventional Flow Map shading. Users can use a brush to specify which areas move and in which direction, assigning different movement paths to a single sky texture.

A structure for separately controlling direction and speed

The painted direction data becomes the animation path, while areas painted with more brush strokes can be configured to move faster. This makes it easier to let only part of a cloud layer drift slowly or emphasize movement in a specific area than to rotate the entire panorama at a uniform speed. Because masks and direction are handled together, sections where changes to the sky are needed can be adjusted precisely to match the scene’s lighting direction or composition.

Edit again even after baking

This feature presents a nondestructive workflow in which the result is baked and saved as a preset, then the same flow can be loaded and modified later. In other words, when repetitive texture movement becomes a problem, the flow data can be repainted and adjusted, allowing control over the presentation of sky animation without having to use volumetric clouds every time.

Connection to lighting work

This tool was introduced as one of the Lighting Suite features planned for inclusion in the World Lighting actor. The concept is to place the actor in a scene, apply presets, and use it alongside features that detect the sun’s position and adjust intensity and color to match the sky. Flow Map painting can therefore be viewed not as a standalone effect, but as part of a lighting workflow intended to align the sky’s movement with the directionality of the light source.

Source: 80 Level — Real-Time Flow Map Painting in Unreal Engine, Karim Yasser’s feature description