Emit controls in Final Cut Pro

Use the Emit controls to apply a radiance effect to 3D text, as if the text were emitting its own light. When you add an emit layer to a 3D title, the following controls appear in the Material section of the 3D Text section of the Text inspector.

The Emit controls in the Material section of the Text inspector

Fill: A pop-up menu to choose whether the light emitted is based on a solid color or a gradient.
Color: A color control (available when Fill is set to Color) to select the color to be emitted.
Gradient: A gradient control (available when Fill is set to Gradient) to create a custom gradient for the colors to be emitted. See Intro to the gradient editor in Final Cut Pro.
Intensity: A slider to adjust the strength of the light emitted from the text object.
Coverage: A slider to adjust how visible the emit layer is, based on the opacity of the layer. A value of 100% (the default) causes the emit layer to be visible regardless of the opacity of the layers beneath it. A value of 0% means that the emit layer shines only where the material is opaque.

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Final Cut Pro User Guide

Emit controls in Final Cut Pro