Mapping Images to Lights

Many light attributes can have an image mapped to them, which gives you greater control over the light. You can use this technique to shape a light more precisely than the basic type allows, give it complicated coloration like concert lighting, or have it project images like a slide projector. For example, if you add an image into a light's Color attribute, the image is projected through it, which produces an effect similar to light coming through a stained-glass window (Figure 15.50).

Figure 15.50. A light with an image mapped into it.

To add an image map to a light's Color attribute:

1.	Click a spot light to select it.
2.	In the Attribute Editor, select the map icon next to the Color slider to open the Create Render Node panel.
3.	In the Create Render Node panel, select the Textures tab, and then click File in the 2D Textures section (Figure 15.51). Figure 15.51. From the Create Render Node panel, select the Textures tab; in the 2D Textures section, select File. This option creates a File node and also opens the Attribute Editor.
4.	In the Attribute Editor, select the File icon next to the Image Name attribute. The Open dialog box appears.
5.	Browse to the folder containing the image you want to use; select it, and click Open. The icon at the top of the Attribute Editor updates with the image you selected.
6.	Render the Perspective view (Figure 15.52). Figure 15.52. The image used is on the left, and the final render of the light with the image mapped into it is on the right. The light displays the image, like a film projector.

Tips

• You can map an image to the intensity of the light as well. This technique is useful for mimicking the shadows of objects that the light would pass through logically but that aren't actually in your scene (such as an out of view window, or a forest canopy).