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C r e a t i n g a L i g h t i n g S c h e m e 9 2 3
F i G u R E 1 7 . 1 3 The Geographic Location – Define Geographic Location dialog box
The dialog box closes and the Geographic Location dialog box opens (see Figure 17.14). If you have Google Earth installed, you can choose to import a .kml or .kmz file (Google Earth placemark files) or to import the location directly from Google Earth.
7. You can define nearly any location in the world as the location for the current drawing by entering the latitude and longitude in this dialog box. For your cabin, you’ll select the city in which it’s located from a map.
8. Click the Use Map button in the top-right corner of the dialog box to open the Location Picker dialog box, as shown in Figure 17.15.
9. In the Region drop-down list below the map, select the region that you prefer. Below that, in the Nearest City drop-down list, select a city within that region. The example here uses North America and Richmond, VA.
A red cross appears over Richmond (or wherever you’ve chosen) in the map. The Time Zone drop-down list displays the accurate time zone based on the location you selected (see Figure 17.15).
10. Click OK to close this dialog box. If a dialog box appears asking if the time zone should be updated, click the Accept Updated Time Zone option. Click OK to close the Geographic Location dialog box.
T I P If a particular city is not listed, you can uncheck the Nearest Big City option and then click directly on the map to set the location or enter the longitudinal and latitudinal coordinates in the left side of the Geographic Location dialog box.
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F i G u R E 1 7 . 1 4 The Geographic Location dialog box
F i G u R E 1 7 . 1 5 The Location Picker dialog box
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Enabling Shadows Shadows add depth and realism to a scene and tie the objects to the surfaces that they rest on or near. You have significant control over the types of shadows cast by the lights in the drawing and whether those shadows appear in the view- ports. You adjust how the shadows appear in the viewport and how they render in the Render tab.
When shadows are turned on, AutoCAD will render them using one of three different methods: simple, sorted, or segment. The simple method is the default used by AutoCAD, and it calculates shadow shaders in random order. By contrast, the sorted and segment methods each calculate shadows in the order they are cast, and they produce higher quality renderings at the cost of machine perfor- mance. Segment shadows will produce the highest quality rendering, but they take the longest time to complete.
In order to ensure that you’ll be able to work through this chapters exercise in a timely manner, we’ll stick to the simple method. Don’t be fooled by its name; while it doesn’t perform the advanced calculations done by the sorted and seg- ment methods, it still produces a detailed rendering without sacrificing system performance.
1. In the Lights panel, click the down arrow under the No Shadows icon and choose Full Shadows from the fly-out menu, as shown in Figure 17.16.
This displays an approximation of the shadows in the viewport.
F i G u R E 1 7 . 1 6 Choosing the Full Shadows option
W A R N I N G the Full Shadows option requires that your video card utilize hardware acceleration. See the Display Backgrounds and Shadows page of the autoCaD 2011 help file to determine whether your system is equipped with hardware acceleration.
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2. Click the Advanced Render Settings button on the right end of the Render panel’s title bar.
3. In the Advanced Render Settings palette that appears, scroll down to the Shadows drop-down list, and make sure Mode is set to Simple and Shadow Map is set to On (see Figure 17.17).
4. Close the Advanced Render Settings palette.
F i G u R E 1 7 . 1 7 The Shadows settings in the Advanced Render Settings palette
the First Render A rendering is the visual result of the program calculating the effects of the lights and materials on the surfaces in the drawing. Let’s make a preliminary render now. Later, you’ll add materials and a background and then render the drawing again.
1. Click the Render button on the Render panel. The Render window opens and after a few moments, the rendering
fills in the graphic area (see Figure 17.18). As you can see, the right side of the cabin is unlit and in total darkness.
2. Click the Point button in the Lights panel (it may be hidden under another light button), and then click to place the light on the ground about 20′ (6100 mm) northeast of the front deck.
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F i G u R E 1 7 . 1 8 The first cabin rendering in the Render window
3. Click the Name option in the context menu that appears at the cursor and give the light the name Northeast Ambient.
As with cameras, you should give your lights descriptive names.
4. Double-click the light to open its Properties palette, and make the following changes:
Position Z: 30 ′ (9150)
Intensity Factor: 60.000
Lamp Intensity: 15,000 Cd
5. Click the down arrow in the Filter Color field, and then choose Select Color. In the Select Color dialog box that appears, change the Color Model to RGB, and enter 252, 250, 212 in the Color field, as shown in Figure 17.19.
This gives the light a pale yellow hue.
6. Click OK to close the Select Color dialog box and close the Properties palette.
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F i G u R E 1 7 . 1 9 The properties for the point light
7. Switch back to the Cam Southeast view if necessary and render the scene again.
As you can see in Figure 17.20, this time the shadows on the right side of the cabin are not as stark as they were previously, but the over- all appearance is still pretty dark. We need to add some ambient light.
8. Open the Advanced Render Settings palette again, and then click the lightbulb icon next to Global Illumination in the Indirect Illumination drop-down list (see Figure 17.21).
This will add a measure of ambient light into your scene without washing it out.
9. This rendering looks a bit better than the last. The Render window maintains a history of the recent renderings,
and you can compare them by clicking on any of the renderings listed in the pane at the bottom of the Render window. To delete a render- ing, select it, right-click, and then choose Remove From The List.
You can continue to tweak the lighting as you want. For indoor proj- ects that require rendering, a good rule of thumb is to expect to dedi- cate 15 to 25 percent of the total project time to creating an excellent lighting scheme. For outdoor scenes, dedicating 5 to 10 percent should be sufficient.
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F i G u R E 1 7 . 2 0 The cabin rendering after adding the second light
F i G u R E 1 7 . 2 1 Turning on Global Illumination
The building looks fine, but it would be nice to have something in the back- ground other than the blank screen, and the lights need to be tweaked.
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Controlling the Background of the Rendering The following are some of the options you can set when choosing a background for the rendering:
the AutoCAD Background This is what you used for the preliminary rendering.
Another Solid Color Use the slider bars to choose another solid color.
Gradient You can use varying colors (usually light to dark) blended together.
image You can supply or choose a bitmap image.
Sun & Sky Background You can use a computer-generated sky. This background has the option of introducing additional ambient illumination into the scene.
You’ll use the Sun & Sky Background option with the Illumination option here:
1. Click the View tab, and then click the Named Views button in the View panel to open the View Manager dialog box.
2. Expand the Model Views entry, and then select Cam Southeast.
3. Expand the drop-down list for the Background Override entry in the General rollout, and then choose Sun & Sky, as shown in Figure 17.22.
F i G u R E 1 7 . 2 2 The Cam Southeast camera selected in the View Manager dialog box
Doing so opens the Adjust Sun & Sky Background dialog box, as shown in Figure 17.23.
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F i G u R E 1 7 . 2 3 The Adjust Sun & Sky Background dialog box
N O T E the sky background options are available only when the light- ing units are not set to generic. this is controlled by the LIGHTINGUNITS system variable. enter LIGHTINGUNITS↵ 2↵ to set the lighting units to International. a setting of 1 sets the lighting units to american, and 0 sets them to generic units.
4. In the Sky Properties rollout, change the Intensity Factor value to 3; then expand the Status drop-down list, and choose Sky Background and Illumination (see Figure 17.23).
5. Click OK to close the Adjust Sun & Sky Background dialog box.
6. Click Set Current in the View Manager dialog box, and then click OK to close it.
7. Open the Advanced Render Settings palette from the Render tab’s Render panel. Scroll down to the Final Gather group, and make sure the Mode is set to Auto or On. Background Illumination will not work if Final Gather Mode is set to Off.
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8. Save your drawing as 17A-3DMOD3.dwg.
9. Render the scene. It will take a little longer to process this image, and you’ll notice the image in the Render window is replaced twice; the first time with a very rough-looking representation of the cabin and then again with a sharper result.
When it is done, the display in your Render dialog box should look similar to Figure 17.24. The background image not only appears behind the cabin and ground, but it also contributes light to the scene.
F i G u R E 1 7 . 2 4 The cabin rendered with the Sun & Sky background and additional illumination
N O T E rendering is a processor-intensive function. It’s not uncommon to experience a lag in computer performance or to hear increased cooling fan activity while a rendering is in progress. to help speed up the rendering time, you’re encouraged to leave autoCaD as the current application and refrain from performing other tasks on your computer if possible.
Adding Materials Adding the proper materials to a scene can greatly increase the realism of the drawing and convey a better sense of size and texture to the person viewing the image. This chapter assumes that you installed the material library that ships with AutoCAD 2011, along with the rest of the package.
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You can assign materials to your drawing objects from several premade librar- ies, you can create materials from scratch, or you can edit materials that originate from the libraries. In the next exercise, you will apply materials from AutoCAD’s libraries.
1. Click the Render tab, and then click the Materials Browser button in the Materials panel to open the Materials Browser palette shown in Figure 17.25.
F i G u R E 1 7 . 2 5 The Materials Browser palette
The Materials Browser palette is divided into two primary areas:
Document Materials: The upper region of the Materials Browser palette displays the materials that have been loaded into your current drawing. Above the name for each material, a small thumbnail preview of the material displays.
Libraries: AutoCAD Materials are filed away into a series of libraries. A list of available libraries along with the material categories within each library display along the left side of the palette. Selecting any library or category on the left will display the materials belonging to that library or category as a series
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of thumbnails along the right side of the palette. The default installation creates two libraries: the Autodesk Library and the My Materials Library.
2. Materials may be added to the current drawing from any of the Libraries listed in the lower portion of the Materials Browser.
If it’s not open already, expand Autodesk Library in the Libraries portion of the Materials Browser. A list of categories containing an assortment of materials displays.
3. Browsing the Wood category, locate and then select the Red Oak Wild Berries material on the right side of the Materials Browser palette.
The Red Oak Wild Berries material will be added to the Document Materials list at the top of the Materials Browser palette.
4. Repeat steps 2 and 3 to load the materials listed in Table 17.1.
t A B L E 1 7 . 1 C A B i n M A t E R i A L S
Category Material name
Pine Yellow Natural No Gloss
Brick Burgundy 12-inch Running
Glass Blue Reflective
Metal Aluminum Satin Brushed
Miscellaneous Grass Dark Bermuda
Shingles - Asphalt 3-Tab Black
Paint Antique White Flat
All of the materials you’ll need for your cabin are now loaded into the cur- rent drawing. However, before those materials are used for rendering they must be assigned to objects in your drawing. Materials can be applied to individual objects, faces, or layers. Whenever possible, it’s best to assign materials to an entire layer as opposed to individual objects or faces. Subscribing to this prac- tice will help ensure the manageability of your model.
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To assign materials to the layers in your drawing:
1. If you haven’t already, switch to the Render tab, and then expand the Materials panel to select the Attach By Layer tool.
The Material Attachment Options dialog box opens to display a list of materials and layers in the current drawing.
2. The Material Attachment Options dialog box, shown in Figure 17.26, is split into two parts. The left side displays a list of materials loaded into the current drawing, and the right side displays a list of layers in the current drawing. By default, the Global material is assigned to each layer.
Locate the Red Oak Wild Berries material on the left side of the dialog box and the A-DOOR-3DOB layer on the right.
F i G u R E 1 7 . 2 6 The Material Attachment Options dialog box
3. Drag the Red Oak Wild Berries material from the left side of the dia- log box onto the A-DOOR-3DOB layer on the right. Verify that the material was applied by checking the Material column in the Layer list on the right side of the dialog box.
4. Repeat this procedure by assigning materials to each of your 3DOB layers, as shown in Table 17.2.
5. Save your drawing as 17A-3DMOD4.dwg.
6. Render your drawing one more time; it should look like Figure 17.27. Notice how the roof is reflected in the living room window.
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t A B L E 1 7 . 2 Layer Material Assignments
A-DECK-3DOB Pine Yellow Natural No Gloss
A-DECK-STRS-3DOB Pine Yellow Natural No Gloss
A-DOOR-THRE-3DOB Aluminum Satin Brushed
A-FNDN-3DOB Burgundy 12-inch Running
A-GLAZ-3DOB Blue Reflective
A-GLAZ-SILL-3DOB Pine Yellow Natural No Gloss
A-ROOF-3DOB Shingles - Asphalt 3-Tab Black
A-ROOF-DECK-3DOB Antique White Flat
A-WALL-EXTR-3DOB Shakes Weathered
A-WALL-INTR-3DOB Antique White Flat
C-TOPO-3DOB Grass Dark Bermuda
Created in earlier exercises:
A-DOOR-3DOB Red Oak Wild Berries
F i G u R E 1 7 . 2 7 The cabin rendered with materials applied to the remaining 3D objects
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N O T E During the rendering process, you probably noticed the small black squares being replaced one at a time by small areas of the rendered drawing. this indicates that autoCaD is using bucket rendering. Before the rendering process begins, autoCaD determines the sequence to process the squares, called buckets, in order to maximize the memory usage and thereby increase the efficiency of the rendering.
Adjusting the Material Mapping Image maps are the components of a material that consist of image files, such as a JPEG or TIFF. When a material uses an image map, its purpose can be to change the color of an object (diffuse maps), to give the illusion of texture (bump maps), or to define the transparency of a surface (opacity maps).
Adjusting the Map Size
The individual properties of all materials are controlled in the Materials Browser palette. Here you’ll find the controls for setting the parameters for the size of the map, which map to use, and several other features for the selected material.
1. In the Render tab, click the Materials Browser icon in the Materials panel.
2. In the Document Materials portion of the Materials Browser palette, right-click on the Shakes Weathered material and select Edit.
The Materials Editor palette opens to display details about the Shakes Weathered material (see Figure 17.28).
3. From the Materials Editor, click on the photographic image found under the Generic group (see Figure 17.28).
4. Selecting the image in the Materials Editor palette will open the Texture Editor palette, shown in Figure 17.29. Expand the Transforms group, and then the Scale group to locate the Sample Size setting.
Enter 2′4″ (710 mm) into the Height textbox. Note how the dimen- sions shown in the preview at the top of the Texture Editor palette update to reflect this change.
5. Close the Texture Editor, Materials Editor, and Materials Browser pal- ettes, and then change your visual style to Realistic.
The Realistic style displays the materials and maps, and the changes that you make to them, all at the expense of system performance (see Figure 17.30). You should use this visual style only when necessary.
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F i G u R E 1 7 . 2 8 The Materials palette with the Shake material selected
F i G u R E 1 7 . 2 9 Modifying the material scale from the Texture Editor palette
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F i G u R E 1 7 . 3 0 View of the cabin using the Realistic visual style
The exterior walls of the cabin consist of flat surfaces, and there are no features that would cause shadows to be cast. The Bump Map option adds apparent tex- ture by adding shadows where they would appear if the surfaces had texture. In the Maps rollout, you can see that only the Diffuse Map option is checked, mean- ing that no map is used to define the opacity and bump features of the material. Opacity maps and bump maps don’t use any of the color information from an image map, but this doesn’t mean that color maps can’t be used—only that the grayscale equivalent of the colors will be interpreted by AutoCAD.
1. Open the Materials Editor palette once again by locating the Shakes Weathered material in the Materials Browser palette.
2. Select the check box next to the Bump group heading in the Materials Browser.
3. In the Bump area, click the Select Image button to open the Select Image File dialog box. It should open to the C:\Program Files\Common Files\Autodesk Shared\Materials2011\assetlibrary_base.fbm\3\
Mats folder; if not, navigate there.
4. Select the Thermal - Moisture.Shakes.Weathered.jpg file, the same file used as the diffuse map, and then click Open.
5. Move the Bump Amount slider to 10 (see Figure 17.31). Figure 17.32 shows the cabin rendered with the new material
the Thermal - Moisture.Shakes .Weathered.jpg image is also included in the Chapter 17 download.
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6. Adjust the mapping and materials for the remaining objects, and then save your file as 17A-3DMOD5.dwg.
There are enough tools and features relating to AutoCAD materi- als to fill several chapters, and this was just an introduction. Some of the features not covered are copying mapping between objects, applying different maps to different surfaces of the same object, and using opacity maps. I strongly encourage you to investigate the full capabilities of the AutoCAD materials.
F i G u R E 1 7 . 3 1 Changing the amount of bump applied to a material
Rendering to a File By default, the Render feature creates a rendering in the Render dialog box only. The picture is not saved unless you explicitly tell AutoCAD to save it. You can also instruct the program as to the quality level of the rendering and the size, in pixels, of the image created. Follow these steps:
1. Switch back to the Conceptual visual style and the Cam Southeast view.
2. From the Render tab’s Render panel, click the Render Output File but- ton and then the Browse For File button to open the Render Output File dialog box.
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F i G u R E 1 7 . 3 2 The cabin with the new material parameters
3. Navigate to the folder where you want to place the new image file, and then select a supported image file type in the Files Of Type drop- down list. For this exercise, choose TIF as the file type, and name the file Cabin Rendering Small.tif (see Figure 17.33). Click the Save button.
F i G u R E 1 7 . 3 3 Saving the final cabin rendering
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4. Depending on the file type you choose in the future, an Options dia- log box, similar to the one shown in Figure 17.34, will appear. In the TIFF Image Options dialog box, select 24 Bits (16.7 Million Colors), make sure the Compressed option is checked and then click OK.
The next time you render the drawing, the rendering will be saved as an image file on your hard drive, and the filename will appear in the Output File Name column of the Render window, with a folder and check mark next to it (see Figure 17.35). The files with clocks and teapots won’t be saved, but you can open them in the Render window by clicking the appropriate filename.
F i G u R E 1 7 . 3 4 The TIFF Image Options dialog box
F i G u R E 1 7 . 3 5 The saved file shown at the bottom of the Render window
5. In the AutoCAD window, expand the Render Presets drop-down list, and select Presentation, as shown in Figure 17.36.
F i G u R E 1 7 . 3 6 Choose the Presentation rendering preset.
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6. Expand the Render panel, expand the Render Output Size drop-down list, and then choose Specify Image Size (see Figure 17.37) to open the Output Size dialog box.
7. In the Output Size dialog box (see Figure 17.38), set Width to 2000 and Height to 1600, and then click OK.
This is the resolution required to print a 10″×8″ image at 200 dots per inch (dpi).
F i G u R E 1 7 . 3 7 Set the output size.
F i G u R E 1 7 . 3 8 The Output Size dialog box
8. Click the Browse For File button to open the Render Output File dialog box. Name this file Cabin Rendering Large.tif, and make it a 24-bit TIF file at 200 dpi. Click OK.
9. Save your drawing and then click the Render button again and wait a while as the new image renders. With the higher quality and larger image size, this may take considerably longer to process.
10. When the rendering is completed, look at the file size in Windows Explorer, and then compare the two images in your image-viewing software. The larger file is much crisper than the smaller image at the expense of increased rendering time.
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This has been a brief introduction to the world of 3D and rendering in AutoCAD, but you should now be oriented to the general way of doing things and have enough tools to experiment further. For a more in-depth discussion of the process, includ- ing rendering, see Mastering AutoCAD 2011 and AutoCAD LT 2011 (Wiley, 2010) by George Omura, or visit the companion site for this book at www.AutoCADNER.com.
Are You Experienced? now you can…
create a loft object using contour linesEE
create and manipulate camerasEE
add sunlight to a sceneEE
place a point lightEE
specify a scene’s real-world locationEE
assign materials to the objects in a drawingEE
adjust mapping and tilingEE
render a drawing and save the result as an image fileEE
glossAry nuMBERS AnD SYMBoLS
A triangular or four-sided flat surface that is the basic unit of a three-dimensional surface.
A set of adjacent flat surfaces that together form a geometrical depiction of a three- dimensional surface. See also 3D surface.
An AutoCAD object that occupies three- dimensional space and represents building components or geometrical objects in the real world. See also object.
A complementary product to AutoCAD, also produced by Autodesk. With 3ds Max, you can create and animate three-dimensional scenes.
A network of adjacent three-dimensional faces that together form a continuous plane. Surfaces may be created as a part of a 3D mesh, or as a procedural or NURBS surface. See also 3D mesh, Procedural surface, and NURBS surface.
Values for locating a point in space that describe its displacement from the origin (0,0,0) point of the drawing.
A shortcut for starting commands. It’s a set of one or two letters that you can enter at the command line instead of the full command.
A linear dimension measuring the distance between two points. The dimension line for an aligned dimension is parallel to a line between the two points.
A function of both model space and floating viewports that represents the true ratio of a scale and is used to correctly size annota- tive objects such as text and blocks. When LTSCALE and MSLTSCALE are set to 1, the annotation scale is also used to accurately display linetypes.
A dimension that measures the angle between two lines or the angle inscribed by an arc.
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The unit in which angle values are displayed. The choices are Decimal Degrees, Degrees- Minutes-Seconds, Grads, Radians, and Surveyor’s units.
The appearance of your screen when AutoCAD is running. It consists of the draw- ing area and surrounding toolbars, menu bars, the command window, andthestatus bar. Also called the graphicaluser interface, GUI, or UI. See also menu bar.
1. A two-dimensional geographical region closed by a boundary such as a polyline. 2. Collection of settings inside a dialog. See also group.
A dimension that updates automatically when the object being dimensioned changes size.
associative hatch pattern
A hatch pattern that updates automatically when the shape of the hatched area is modi- fied. See also hatch pattern.
User-defined data attached to a block defini- tion that’s stored as text and entered upon insertion stored. AutoCAD object. See object.
A feature of AutoCAD that works with the Object Snap tools by displaying a symbol on
the places that can be snapped to within the drawing. Each of these Object Snap modes has a different AutoSnapsymbol. The symbol appears when the cursor is near a location where the active object snap can be used. See also Object Snap mode.
A dimensioning option that allows you to do multiple measurements from a designated origin.
1. The initial point of reference for a number of modifying commands including COPY, MOVE, ROTATE, STRETCH, and SCALE. 2. The insertion point for a drawing as designated by the BASE command.
See Surveyor’s units.
To transform an external reference file into a permanent part of the host file as a block. See also external reference.
See block reference.
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The description of a grouping of AutoCAD objects that is stored with the drawing file and includes a name, an insertion point, and a listing of objects in the grouping.
An instance of a grouping of objects that is inserted into a drawing and is based on the block definition for that grouping. Informally called a block.
The procedure that uses the volumes of two or more objects to create a single object by combining, subtracting, or finding the inter- section of the selected volumes.
A value that can be assigned to colors and linetypes so that objects receive their color and linetype properties according to the layer on which they reside.
Cartesian coordinate system
A two-dimensional system of locating points on a plane. It uses a horizontal (X) and a ver- tical (Y) component to locate a point relative to the 0,0 point or origin.
A submenu that appears adjacent to the cur- rent menu when an option with an arrow next to it is clicked.
See point filters.
The information in the text window at the bottom of the screen that displays Command: prompts. This is where you see what you’re entering through the keyboard. When the Dynamic Input option is active, the command-line input appears at the cur- sor as well. See also command window and dynamic input.
The prompt shown at the command line when no commands are currently running.
The window at the bottom of the user inter- face where command prompts and user input are shown. See also command line.
A menu that appears on the drawing area, usually as the result of a right-click, and contains options relevant to what the user is doing at that moment.
contextual Ribbon tab/panel
A Ribbon tab or Ribbon panel that appears on the Ribbon as a result of selecting specific object types or starting certain commands.
A dimensioning option that allows you to place sequential dimensions that are adjacent to each other so that the dimension lines are aligned.