AmbientLight

AmbientLight has no meaningful lighting direction. Unlike DirectionalLight, PointLight, and SpotLight, it has no beam vector, cone, or source-to-surface distance. That makes it useful as fill: it raises dark regions and reduces lighting contrast but does little to model form by itself.

The node has one optional orange SceneInput that accepts a 3D scene or geometry stream. When SceneInput is not needed, AmbientLight is normally connected as its own branch into Merge3D with geometry, cameras, and other lights. Its output remains scene3d; normal RGBA appears only at Renderer3D.Image.

AmbientLight Transform controls are easy to misread. The directionless light itself has no meaningful position or rotation direction. With no SceneInput, Translation mainly moves the onscreen viewer widget out of the way. With SceneInput connected, Resolve applies the node Transform to the entire incoming scene, so it behaves as a parent/scene transform rather than as light aiming.

Controls contains Enabled, Color/RGB, and Intensity. Intensity is the primary quantitative control. The current reference describes 0.2 as 20 percent light: a perfectly white texture lit only by AmbientLight at 0.2 would render at roughly 20 percent gray. Actual scene appearance still depends on material lighting response and the renderer path.

AmbientLight is most useful as fill. Excessive Intensity lifts the dark side so far that a directional key light stops modeling depth; materials become flatter and the scene can look washed out. Build the key light first, then add only enough ambient fill to preserve useful shadow detail.

A light affects only the relevant 3D scene scope. Geometry and AmbientLight must meet in the same scene3d graph through SceneInput or Merge3D, the material must respond to lighting, and Renderer3D must evaluate lighting. Adding AmbientLight to the Flow is not equivalent to a 2D Brightness/Contrast operation.