Projecting animated light gel over terrain

How can I set up a texture movie to project from a light onto a Unity native terrain object? There aren't any UVs, are there?

Here's an example: Animated GIF

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Terrain does have UVs (maybe you need to add at least one texture for that). I believe coordinates should be from 0 to 1. So in theory you should be able to do with by switching between multiple textures.