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AutoCAD Tutorial

AutoCAD 3D Modeling: Point Light

August 9, 2004

A point light radiates light rays equally in all directions. It generates a similar effect to a light bulb. Point lights can generate shadows. You may use several point lights in a scene. However, it is better to limit the number of point lights to have more control over the parameters. The following tutorial shows you how to install and change parameters of point lights. It also demonstrates the effect of point lights on some 3D models. Note that when you install a point light you also remove the default light. Therefore the only lights in effect are those that you install.

► This tutorial is designed for AutoCAD 2005 though might be applicable to other releases.
► In this tutorial user entries are in boldface.
► The 8 symbol represents pressing Enter.

1. Download and then open r16_point_light.dwg. The file contains some 3D solid models shown in a single viewport [Figure 1].

Note: If you are using AutoCAD 2002 or an earlier release download r15_ambient_light.dwg.

Figure 1

2. Invoke the LIGHT command (choose View > Render > Light...). The Light dialog box appears [Figure 2].

Figure 2

3. From the drop-down list next to the New button, select Point Light [Figure 3].

Figure 3

4. Click New. The "New Point Light" dialog box appears [Figure 4].

Figure 4

5. In Light Name box on the top left corner of dialog box, type P1. You could type in another name.

6. Change the intensity value to 4. Highlight the text in Intensity box and then type in 4 to replace the existing value.

7. In Position section, click the Modify button to modify the location of point light. The dialog box disappears. Define the location of light icon as follows and then press Enter to return to the dialog box.

Enter light location <current>: 5,0,4 8

8. In both dialog boxes click OK to save changes and close them.
9. Invoke the RENDER command (View > Render > Render...). The rendered image appears [Figure 5].

Figure 5

10. Repeat the LIGHT command. Click the Modify button. In "Modify Point Light" dialog box select the "Shadow On" option [Figure 6]. In both dialog boxes click OK.

Figure 6

11. Repeat the RENDER command. The effect of shadow appears on the image [Figure 7].

Figure 7

12. Invoke the LIGHT command once more. Create a new light point (Refer to step 3 for more information).

13. In the "New Point Light" dialog box define the light name and intensity as shown in Figure 8.

Figure 8

14. Change the location of the light as follows (Refer to step 7 for more information):

Enter light location <current>: -20,-10,30 8

15. In both dialog boxes click OK.

16. Render the scene [Figure 9].

Figure 9

About the Author

Alireza Parsai is the founder of cadpanel.com. He is a mechanical engineer with more than 12 years experience with AutoCAD. Alireza is an Autodesk Authorized Author, the CAD consultant for HiTech, Canada Institute, a contributing editor for Augiworld magazine, a writer for CAD Digest, and an instructor for AUGI Training Program. He has written 8 books in Farsi, 3 booklets in English, and more than 100 articles for different magazines and newsletters. You can reach Alireza by phone at +1 (416) 513 1535, by email at alirezap@htinsititute.com or visit his website www.cadpanel.com.

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