Spotlights

Spotlights project a cone of light in their forward (+Z) direction. The width of this cone is defined by the light’s ‘Spot Angle’ parameter. Light will ‘falloff’ from the source position towards the extent of the light’s range, where it will eventually diminish to zero. Light also diminishes at the edges of the Spotlight’s cone. Widening the Spot Angle increases the width of the cone and with it, increases the size of this fade, known as the ‘penumbra’.

Spotlights have many useful applications for scene lighting. They can be used to great effect as street lights, wall downlights or used dynamically, for creating effects like a flashlight. As their area of influence can be precisely controlled, Spotlights are extremely useful for creating focus on a character or for creating dramatic stage lighting effects

Light will diminish as distance increases from the source. Notice how light also fades towards the edges of the cone. We call this the Light’s penumbra and this increases as the angle of the cone increases.

Like Point Lights, Spotlights do not presently support indirect shadowing when using Precomputed Realtime GI. This means that light produced by Spotlights will travel through geometry and will bounce on the other side. Placement therefore needs to be carefully considered.