Fog3D

Fog3D is a true classic-Fusion 3D tool rather than the 2D Fog node that works from rendered depth channels. Blackmagic describes Fog3D as depth-cue fog operating completely in 3D space and effectively re-texturing geometry with a color correction based on distance from the camera.

The node has two inputs with different data domains. The orange SceneInput is required and accepts classic Fusion scene3d. The green DensityTexture is optional and accepts a 2D image. It is not a second scene and not a three-dimensional density field.

DensityTexture modulates the fog color and is effectively projected onto the scene from the camera. A FastNoise, Background or image therefore creates camera-projected 2D variation rather than world-space volumetric clouds with internal parallax.

Fog Color defines the base atmospheric color. When DensityTexture is connected, that color is multiplied by the texture pixels, so a dark map can suppress the fog while a colored map can tint it non-uniformly across the view.

With Radial disabled, fog distance is based on perpendicular distance to a plane parallel to the camera near plane and passing through the eye point. This is convenient for camera-depth cueing because objects at similar view depth receive similar fog even when separated across X/Y.

Radial changes the metric to true radial distance from the eye point. This can prevent off-axis objects from changing fog merely as they move across the frustum, but it can also make the edges of a close wide image plane foggier than its center because those edges are physically farther from the camera.

Fog Type selects the distance-falloff curve. Linear gives a direct art-directable transition between Near and Far; Exp accumulates nonlinearly; Exp2 produces a stronger exponential response. These are falloff curves, not different physical volume simulations.

Near Fog Distance marks the start of the useful fog range and Far Fog Distance marks the point of maximum fog effect. Fog is cumulative with distance, so an overly narrow range can flatten the entire scene into the fog color very quickly.

Show Fog In View is a viewer diagnostic rather than a final-render switch. By default the fog is visible when the scene is viewed through a Camera; enabling this control makes it visible from other 3D viewer viewpoints as well.

Enable disables the fog-effect portion of the tool. Blackmagic distinguishes it from the Inspector's red tool switch: the red switch bypasses the whole tool, while Enable controls the effect processing itself.

For a deterministic shot setup, include Camera3D in the incoming scene before Fog3D, normally via Merge3D. A common chain is geometry + Camera3D → Merge3D → Fog3D → Renderer3D.

Fog3D can participate in the 3D rendering pipeline with antialiasing and depth-of-field, but it is still surface depth cue rather than a physically participating volumetric medium. True volumetric smoke/fog requires a different volume/deep workflow.

Fog3D.Output remains classic Fusion scene3d. It cannot feed MediaOut or ordinary 2D image effects directly; the scene3d-to-RGBA boundary is Renderer3D.Image.

The bundled project screenshot confirms Enable, Show Fog In View, Fog Color RGB, Radial, Linear/Exp/Exp2 and Near/Far. Live Resolve 21/21.1 execution was not performed in this package, so exact renderer/AA/DOF visual response remains a target-build verification item.