The final light source is called the Weblight source. It is similar to the Point light source. The difference is that it adds the ability to precisely determine the intensity distribution of the light source. The Weblight tool button can be found in the Lights panel within the Visualize panel in the 3D Basics workspace, as shown in the following screenshot. An alternative method is to type the command name, WEBLIGHT, (or just type WEB) and then press Enter, as shown in the following screenshot:

If you are using the 3D Modeling workspace, you can find the Weblight tool button in the Lights panel within the Visualize panel.

You can add a Weblight source to the model, as shown in the following step-by-step example:

1. After starting the Weblilght source command, use the mouse cursor to specify the source location. In the following screenshot, the top end of the vertical line is used as the source location.
2. Use the mouse cursor to specify the target location. In the following screenshot, the bottom end of the vertical line is used as the target location:

3. After specifying the location, a settings menu will appear. For details on these options, please refer to the Creating a Point light source section of this chapter (except for the weB option, which will be discussed later in the chapter). To create the light source using the default settings and end the command, click on exit.
4. The command terminates and the light source is created:

In the previous example, the Weblight source was created with default settings, that is, no custom intensity distribution of the light source was set, and that's why it is just emitting the same light in all directions like a point source. To add a map for the intensity distribution, you need to associate the Weblight source with a web file. To do that, select the Weblight source, right-click anywhere on the screen, and then select Properties.

In the Photometric Web section of the PROPERTIES palette, click on the small browse icon next to Web file. This will open the Select Web File window. Browse to the location of the desired web file and open it. You can also click once on the filename to see a preview of the intensity distribution, as shown in the following screenshot. AutoCAD may come with a number of preset web files. In addition to that, light fixture manufacturers may also provide web files for their products that you can download and use:

An alternative method of adding the web file is during the Weblight source creation. Select the option called weB from the option list that appears in step 3 in the previous Weblight creation example. Then, type the name of the desired web file.

It is also possible to rotate a given intensity distribution profile around any of the three main axes. This is done using the three rotation options found in the Web offsets section in the PROPERTIES palette of the Weblight source. Simply type the rotation angle for each axis and then close the PROPERTIES palette.