Create a light and change light settings



A light layer can affect the colors of the 3D layers that it shines on, depending on the light’s settings and the Material Options properties of the 3D layers. Each light, by default, points to its point of interest.

Lights can be used to illuminate 3D layers and to cast shadows. You can use lights to match lighting conditions of the scene into which you are compositing or to create more interesting visual results. For example, you can use light layers to create the appearance of light streaming through a video layer as if it were made of stained glass.

You can animate all of the settings for a light, except for the light type and the Casts Shadows property.

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Light types: Spot (upper-left); Point (upper-right); Parallel (lower-left); Ambient (lower-right)

A.
Point of interest

B.
Light icon

You can specify which 3D layers a light affects by designating the light as an adjustment layer: place the light in the Timeline panel above the layers on which you want it to shine. Layers that are above a light adjustment layer in the layer stacking order in the Timeline panel do not receive the light, regardless of the positions of the layers in the Composition panel.

Create a light

 Choose Layer > New > Light, or press Ctrl+Alt+Shift+L (Windows) or Command+Option+Shift+L (Mac OS).
Note: By default, new layers begin at the beginning of the composition duration. You can instead choose to have new layers begin at the current time by deselecting the Create Layers At Composition Start Time preference (Edit > Preferences > General (Windows) or After Effects > Preferences > General (Mac OS)).

Change light settings

  Double-click a light layer in the Timeline panel or select the layer and choose Layer > Light Settings.

Light settings

Light Type
Parallel emits directional, unconstrained light from an infinitely distant source, approximating the light from a source like the Sun. Spot emits light from a source that is constrained by a cone, like a flashlight or a spotlight used in stage productions. Point emits unconstrained omnidirectional light, like the rays from a bare light bulb. Ambient creates light that has no source but rather contributes to the overall brightness of a scene and casts no shadows.
Note: Because the position in space of an Ambient light does not affect its influence on other layers, an Ambient light does not have an icon in the Composition panel.

Intensity
The brightness of the light. Negative values create nonlight. Nonlight subtracts color from a layer. For example, if a layer is already lit, creating a directional light with negative values also pointing at that layer darkens an area on the layer.

Cone Angle
The angle of the cone surrounding the source of a light, which determines the width of the beam at a distance. This control is active only if Spot is selected for Light Type. The cone angle of a Spot light is indicated by the shape of the light icon in the Composition panel.

Cone Feather
The edge softness of a spotlight. This control is active only if Spot is selected for Light Type.

Color
The color of the light.

Casts Shadows
Specifies whether the light source causes a layer to cast a shadow. The Accepts Shadows material option must be On for a layer to receive a shadow; this setting is the default. The Casts Shadows material option must be On for a layer to cast shadows; this setting is not the default.
Press Alt+Shift+C (Windows) or Option+Shift+C (Mac OS) to toggle Casts Shadows for selected layers. Press AA to show Material Options properties in the Timeline panel.

Shadow Darkness
Sets the darkness of the shadow. This control is active only if Casts Shadows is selected.

Shadow Diffusion
Sets the softness of a shadow based on its apparent distance from the shadowing layer. Larger values create softer shadows. This control is active only if Casts Shadows is selected.

Simulate light falloff

Native After Effects lights don’t include falloff properties, which means that the illumination of a layer does not decrease as the distance between the layer and the light increases.

You can simulate light falloff using expressions or one of several third-party plug-ins created for this purpose.

Dan Ebberts provides an expression on his MotionScript website that uses expressions on the Material Options properties of a layer to simulate the result of light falloff when the layer is farther from the light.

Online resources about lights

Eran Stern provides a video tutorial on the Creative COW website that demonstrates the use of lights as adjustment layers, to precisely control which layers are affected by which lights.

Chris Meyer provides a basic overview of lights and their properties in a video tutorial on the Lynda.com website.

Trish and Chris Meyer provide a tutorial for using 3D layers, lights, and cameras in a PDF excerpt from their book After Effects Apprentice on the Focal Press website.