AutoCAD and Its Applications—Comprehensive 2020, 27th Edition Page 486 (1558 of 1650)

Copyright Goodheart-Willcox Co., Inc. 486 AutoCAD and Its Applications—Advanced Lighting Units There are two settings for lighting units available in AutoCAD: American (foot- candles) and International (lux). Each type of lighting is called photometric lighting. Photometric lighting is physically correct and attenuates at the square of the distance from the source. For more accuracy, photometric data fi les can be imported from lighting manufacturers. The LIGHTINGUNITS system variable sets what type of lighting is used. The setting can be changed using the International lighting units drop-down list in the expanded Lights panel on the Visualize tab of the ribbon. Refer to Figure 18-6. A setting of 1 for the LIGHTINGUNITS system variable specifi es American lighting units. A setting of 2 specifi es International lighting units. This is the default setting. The only difference between the two settings is that American units are displayed as foot-candles (fc) and International units are displayed as lux (lx). NOTE NOTE All lights in AutoCAD are calculated using photometric lighting. Non-photometric AutoCAD lighting, also called generic lighting, was available prior to AutoCAD 2016 and was the only type of lighting used prior to AutoCAD 2008. This lighting provided very nice results, but the settings were not based on any real measurements. For compatibility purposes, it is recommended to update non-photometric lights created in previous releases to photometric lights. Exposure and White Balance The brightness and color temperature of lighting in the scene can be adjusted using the sliders in the expanded Lights panel on the Visualize tab of the ribbon. Refer to Figure 18-6. These are global controls that provide a quick way to adjust the lighting. The Light Exposure slider is used to adjust the brightness. Lower values make the scene brighter and higher values make it darker. The Light White Balance slider is used to adjust the color temperature of lighting based on the Kelvin temperature value (k). Higher values make the light warmer and lower values make it cooler. Warmer lights are more yellow and cooler lights appear bluish. Pick to toggle default lighting on and off Exposure level Color temperature Pick to toggle display of light glyphs Pick to open Lights in Model palette Lighting units Pick to open the Sun Properties palette Pick to toggle sunlight on and off Date and time Sky setting Pick to set the geographic location A B Figure 18-6. The tools for adding and controlling lights. A—Tools in the Lights panel of the Visualize ribbon tab. B—Tools in the Sun & Location panel of the Visualize ribbon tab.

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Copyright Goodheart-Willcox Co., Inc. 486 AutoCAD and Its Applications—Advanced Lighting Units There are two settings for lighting units available in AutoCAD: American (foot- candles) and International (lux). Each type of lighting is called photometric lighting. Photometric lighting is physically correct and attenuates at the square of the distance from the source. For more accuracy, photometric data fi les can be imported from lighting manufacturers. The LIGHTINGUNITS system variable sets what type of lighting is used. The setting can be changed using the International lighting units drop-down list in the expanded Lights panel on the Visualize tab of the ribbon. Refer to Figure 18-6. A setting of 1 for the LIGHTINGUNITS system variable specifi es American lighting units. A setting of 2 specifi es International lighting units. This is the default setting. The only difference between the two settings is that American units are displayed as foot-candles (fc) and International units are displayed as lux (lx). NOTE NOTE All lights in AutoCAD are calculated using photometric lighting. Non-photometric AutoCAD lighting, also called generic lighting, was available prior to AutoCAD 2016 and was the only type of lighting used prior to AutoCAD 2008. This lighting provided very nice results, but the settings were not based on any real measurements. For compatibility purposes, it is recommended to update non-photometric lights created in previous releases to photometric lights. Exposure and White Balance The brightness and color temperature of lighting in the scene can be adjusted using the sliders in the expanded Lights panel on the Visualize tab of the ribbon. Refer to Figure 18-6. These are global controls that provide a quick way to adjust the lighting. The Light Exposure slider is used to adjust the brightness. Lower values make the scene brighter and higher values make it darker. The Light White Balance slider is used to adjust the color temperature of lighting based on the Kelvin temperature value (k). Higher values make the light warmer and lower values make it cooler. Warmer lights are more yellow and cooler lights appear bluish. Pick to toggle default lighting on and off Exposure level Color temperature Pick to toggle display of light glyphs Pick to open Lights in Model palette Lighting units Pick to open the Sun Properties palette Pick to toggle sunlight on and off Date and time Sky setting Pick to set the geographic location A B Figure 18-6. The tools for adding and controlling lights. A—Tools in the Lights panel of the Visualize ribbon tab. B—Tools in the Sun & Location panel of the Visualize ribbon tab.

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Copyright Goodheart-Willcox Co., Inc. Chapter 18 Lighting 485 AutoCAD Lights AutoCAD Lights AutoCAD has three types of lighting: default lighting, sunlight with or without sky illumination, and user-created lighting. Default lighting is the lighting automati- cally available in the scene. It is composed of one or two default light sources that appear to be originating from above and to the left of the viewer. As the viewpoint is changed, the light sources follow to maintain the same illumination of the scene. There is no control over default lighting and it must be shut off whenever one of the other types of lighting is used. As you saw in Chapter 16, sunlight may be added to any scene. AutoCAD uses a distant light to simulate the parallel rays of the sun. The date and time of day can be adjusted to create different sunlight illumination. Sky illumination may also be added with sunlight to simulate light bouncing off objects in the scene and particles in the atmosphere. This helps create a more-natural feel. User-created lighting results when you add AutoCAD light objects to the drawing. There are four types of user-created lights: distant light, weblight, point light, and spotlight. See Figure 18-5. A distant light is a directed light source with parallel light rays. A weblight is a directional point light containing light intensity (photometric) data. A point light is like a lightbulb with light rays shining out in all directions. A spotlight is like a distant light, but it projects light in a cone shape instead of having parallel light rays. When created, point lights, weblights, and spotlights are represented by light glyphs, or icons, in the drawing. To suppress the display of light glyphs, pick the Light Glyph Display button in the expanded Lights panel on the Visualize tab of the ribbon. The button is blue when light glyphs are displayed. The default lights, sun, and distant lights are not represented by glyphs. In this section, you will learn how to add lights. You will also learn how to adjust the various properties of sunlight and AutoCAD light objects. The tools for working with lights can be accessed using the command line, tool palettes, and the Lights and Sun & Location panels on the Visualize tab of the ribbon. See Figure 18-6. So that you will never work with a completely dark scene, default lighting is applied in the viewport and to the rendering if no other lights are added. In order for your lights to be applied, you must switch between default lighting and user lighting. To do this, pick the Default Lighting button in the expanded Lights panel on the Visualize tab of the ribbon. This button toggles the lighting between default lighting and whatever lights are available in the scene. When default lighting is on, the button is blue. If you elected for AutoCAD to do so, the default lighting will be automatically shut off when sunlight is turned on or a user-created light is added to the scene. LIGHTGLYPHDISPLAY Ribbon Visualize Lights Light Glyph Display Type LIGHTGLYPH- DISPLAY Figure 18-5. AutoCAD has four types of user-created lights: distant, point, weblight, and spotlight. A weblight is really a targeted point light. It projects in all directions, but may be predominant in one direction. A full-color image is provided on the companion website. www.g-wlearning.com/CAD/

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Copyright Goodheart-Willcox Co., Inc. Chapter 18 Lighting 485 AutoCAD Lights AutoCAD Lights AutoCAD has three types of lighting: default lighting, sunlight with or without sky illumination, and user-created lighting. Default lighting is the lighting automati- cally available in the scene. It is composed of one or two default light sources that appear to be originating from above and to the left of the viewer. As the viewpoint is changed, the light sources follow to maintain the same illumination of the scene. There is no control over default lighting and it must be shut off whenever one of the other types of lighting is used. As you saw in Chapter 16, sunlight may be added to any scene. AutoCAD uses a distant light to simulate the parallel rays of the sun. The date and time of day can be adjusted to create different sunlight illumination. Sky illumination may also be added with sunlight to simulate light bouncing off objects in the scene and particles in the atmosphere. This helps create a more-natural feel. User-created lighting results when you add AutoCAD light objects to the drawing. There are four types of user-created lights: distant light, weblight, point light, and spotlight. See Figure 18-5. A distant light is a directed light source with parallel light rays. A weblight is a directional point light containing light intensity (photometric) data. A point light is like a lightbulb with light rays shining out in all directions. A spotlight is like a distant light, but it projects light in a cone shape instead of having parallel light rays. When created, point lights, weblights, and spotlights are represented by light glyphs, or icons, in the drawing. To suppress the display of light glyphs, pick the Light Glyph Display button in the expanded Lights panel on the Visualize tab of the ribbon. The button is blue when light glyphs are displayed. The default lights, sun, and distant lights are not represented by glyphs. In this section, you will learn how to add lights. You will also learn how to adjust the various properties of sunlight and AutoCAD light objects. The tools for working with lights can be accessed using the command line, tool palettes, and the Lights and Sun & Location panels on the Visualize tab of the ribbon. See Figure 18-6. So that you will never work with a completely dark scene, default lighting is applied in the viewport and to the rendering if no other lights are added. In order for your lights to be applied, you must switch between default lighting and user lighting. To do this, pick the Default Lighting button in the expanded Lights panel on the Visualize tab of the ribbon. This button toggles the lighting between default lighting and whatever lights are available in the scene. When default lighting is on, the button is blue. If you elected for AutoCAD to do so, the default lighting will be automatically shut off when sunlight is turned on or a user-created light is added to the scene. LIGHTGLYPHDISPLAY Ribbon Visualize Lights Light Glyph Display Type LIGHTGLYPH- DISPLAY Figure 18-5. AutoCAD has four types of user-created lights: distant, point, weblight, and spotlight. A weblight is really a targeted point light. It projects in all directions, but may be predominant in one direction. A full-color image is provided on the companion website. www.g-wlearning.com/CAD/

Copyright Goodheart-Willcox Co., Inc. Chapter 18 Lighting 487 Sunlight and Location To turn sunlight on or off, pick the Sun Status button in the Sun & Location panel on the Visualize tab of the ribbon. Refer to Figure 18-6. This button is blue when sunlight is on. Sunlight can also be turned on or off in the Sun Properties palette, which is discussed in the next section. Sunlight is not represented by a light glyph. The date, time, and geographic location can also be set in the Sun & Location panel on the Visualize tab of the ribbon. These properties determine how the scene is illuminated by the sun. To change the current date, drag the Date slider left or right. Sunlight must be on for the slider to be enabled. As you drag the slider, the date is displayed on the right-hand end of the slider. The time is changed in the same manner. Drag the Time slider left or right. As you drag the slider, the time is displayed on the right-hand end of the slider. The location of the scene can be set to an actual geographic location. This is impor- tant if you want to replicate the lighting and shadows of an actual site. The Set Location drop-down list on the Sun & Location panel on the Visualize tab of the ribbon provides two options for setting the location of the scene: From Map and From File. The From Map option allows you to select a geographic location from the Autodesk online maps service. The From File option allows you to specify the location by importing a KML or KMZ fi le. KML stands for Keyhole Markup Language. A KML fi le contains latitude, longitude, and, sometimes, other data to pinpoint a location on Earth. A KMZ fi le is a zipped KML fi le. In order to use the Autodesk online maps service, you must fi rst sign in to or create an Autodesk account. To create an Autodesk account, select the Sign In button in the InfoCenter and select Sign In to Autodesk account. Select Create Account to create a user name and password. After creating the account, you can use the Autodesk online maps service. Select From Map from the Set Location drop-down list and pick Yes when asked if you want to use live map data. The Geographic Location-Specify Location dialog box appears and allows you to select a location directly on the map. See Figure 18-7. If necessary, use SUNSTATUS Ribbon Visualize Sun & Location Sun Status Type SUNSTATUS GEOGRAPHICLOCATION Ribbon Visualize Sun & Location Set Location From Map Type GEOGRAPHIC- LOCATION GEO NORTH NORTHDIR Pick to specify the coordinate system Zoom tools Pick to locate your current location Current Map Type drop-down list Enter a location to search Indicates selected location Pick to center the map to the geographic marker Figure 18-7. The Geographic Location-Specify Location dialog box is used to specify geographic location data. Pick directly on the map to set the location.

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Copyright Goodheart-Willcox Co., Inc. Chapter 18 Lighting 487 Sunlight and Location To turn sunlight on or off, pick the Sun Status button in the Sun & Location panel on the Visualize tab of the ribbon. Refer to Figure 18-6. This button is blue when sunlight is on. Sunlight can also be turned on or off in the Sun Properties palette, which is discussed in the next section. Sunlight is not represented by a light glyph. The date, time, and geographic location can also be set in the Sun & Location panel on the Visualize tab of the ribbon. These properties determine how the scene is illuminated by the sun. To change the current date, drag the Date slider left or right. Sunlight must be on for the slider to be enabled. As you drag the slider, the date is displayed on the right-hand end of the slider. The time is changed in the same manner. Drag the Time slider left or right. As you drag the slider, the time is displayed on the right-hand end of the slider. The location of the scene can be set to an actual geographic location. This is impor- tant if you want to replicate the lighting and shadows of an actual site. The Set Location drop-down list on the Sun & Location panel on the Visualize tab of the ribbon provides two options for setting the location of the scene: From Map and From File. The From Map option allows you to select a geographic location from the Autodesk online maps service. The From File option allows you to specify the location by importing a KML or KMZ fi le. KML stands for Keyhole Markup Language. A KML fi le contains latitude, longitude, and, sometimes, other data to pinpoint a location on Earth. A KMZ fi le is a zipped KML fi le. In order to use the Autodesk online maps service, you must fi rst sign in to or create an Autodesk account. To create an Autodesk account, select the Sign In button in the InfoCenter and select Sign In to Autodesk account. Select Create Account to create a user name and password. After creating the account, you can use the Autodesk online maps service. Select From Map from the Set Location drop-down list and pick Yes when asked if you want to use live map data. The Geographic Location-Specify Location dialog box appears and allows you to select a location directly on the map. See Figure 18-7. If necessary, use SUNSTATUS Ribbon Visualize Sun & Location Sun Status Type SUNSTATUS GEOGRAPHICLOCATION Ribbon Visualize Sun & Location Set Location From Map Type GEOGRAPHIC- LOCATION GEO NORTH NORTHDIR Pick to specify the coordinate system Zoom tools Pick to locate your current location Current Map Type drop-down list Enter a location to search Indicates selected location Pick to center the map to the geographic marker Figure 18-7. The Geographic Location-Specify Location dialog box is used to specify geographic location data. Pick directly on the map to set the location.

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