This Read Me file contains last-minute additions and corrections to the Adobe Dimensions documentation.
INSTALLING ADOBE DIMENSIONS
The Adobe Dimensions package contains three disks. Depending on the configuration of your system, you will use either disks 1 and 2 or disks 1 and 3. It is important to keep backups of all three disks. If you ever want to install Adobe Dimensions on a different system, you might need the disk you did not use in this installation.
TUTORIAL
The file "Cookie lid without guides," shown in the Import dialog box on page 27, is not included in the Tutorial folder. It is not needed to complete the tutorial.
PREVIEWING OBJECTS IN YOUR DRAWING PROGRAM
In certain two-dimensional drawing programs, white specks, or "cracks," may appear in your Adobe Dimensions artwork. These cracks will not appear in the final output that is printed on a Postscript printer or imagesetter.
KEYBOARD SHORTCUTS
The following keyboard shortcuts are not specified on the Quick Reference Card.
• In all dialog boxes, you can press the first letter of the button name instead of clicking the button. For example, if you quit Adobe Dimensions without saving your file, a dialog box appears giving you the opportunity to save your file. In addition to using the buttons to dismiss the dialog box, you can use the following keyboard shortcuts:
• Press D to exit without saving.
• Press C to cancel and return to Dimensions.
• Press S to open the Save dialog box.
• To move a light from front to back or from back to front, Command-click the light.
• To scale or rotate a copy of a selected object, or to draw an object from its center, you must begin dragging the object and THEN hold down the Option key.
• Option-clicking any transformation tool opens the tool dialog box; to open a drawing tool dialog box, select the tool, hold down the Option key, and click anywhere in the workspace.
IMPROVING PERFORMANCE
Once you become familiar with the capabilities of Adobe Dimensions and begin creating final artwork, you can use the following techniques to improve the performance of your system.
• When creating artwork to revolve or extrude, don't use more points or curves than necessary.
• Revolved open paths render much more quickly if you select caps, or position the path so that its two end points are touching the guide.
• With the exception of Ruled Surfaces, Show Axis Indicators, and Beep When Rendered, all options in the Preferences dialog box (especially Clip Mapped Artwork) affect performance. We recommend that you deselect all of these options while you are arranging your artwork. Once you are satisfied with the artwork, you can then select the Preferences necessary to achieve your desired effect.
• The more strokes in a given piece of artwork, the more time will be required to render the artwork and to map it onto an object .
PREPARING ARTWORK FOR EXTRUDING OR REVOLVING
Adobe Dimensions extrudes and revolves open paths differently from closed paths. A closed path extrudes like a solid shape, and an open path extrudes like a ribbon. If you want a revolved or extruded object to appear as one solid object make sure that all paths are joined.
You can also extrude or revolve multiple objects simultaneously. When revolving multiple objects that have been imported, you will get different results depending on how the files are set up. If the file contains multiple objects and one guide, all objects will revolve around the guide. If the file contains multiple objects and no guides, each object will revolve around the default axis to the object's left. If you want multiple objects to rotate around multiple placed guides, you must import each object and its guide separately.
When your drawing program converts type to outlines, it may create more points than necessary to describe the shape of the letter. It's a good idea to delete any extraneous points both for performance and to reduce the chance of the bevel intersecting itself.
It is possible to create a shape that looks like a closed path, but is actually a group of paths. If you extrude a shape and the top is missing or you revolve a path and a surface is missing, the shape or path is probably composed of more than one path. Return to your drawing program, join the paths, and try the operation again.
Because Adobe Dimensions does not support intersecting objects, the program warns you if an object you are extruding or revolving will have intersecting surfaces or if a bevel is interpenetrating (described in Chapter 3 of the user guide under "Applying Bevels"). However, in a few cases, artwork may be too complicated for Adobe Dimensions to detect that surfaces will intersect. If your rendered object is missing a surface or if two surfaces are folded into each other, try simplifying the artwork.
VIEWING OBJECTS
By changing perspective or changing view angle, it is possible to position an object so that it is no longer visible. For example, if telephoto perspective is selected, you are viewing the object as if it was 28 inches away. If you then select a wide angle perspective, the object is viewed as if it were 5 inches away. The 23-inch difference between these two views can cause an object to no longer be visible. This situation can also occur when changing view angles. For example, an object can be moved so far back on the z-axis that when you switch to back view you are still in front the object, and the object is not visible. For more information on viewing objects, see Chapter 3 of the user guide.
MAPPING ARTWORK CONTAINING STROKED LINES
As mentioned in the user guide, strokes are not shaded when the Shade Mapped Artwork option is selected. In addition, stroked lines are not scaled when artwork is scaled in the Artwork Mapping dialog box. If you choose to use strokes in your artwork and want to keep them from becoming disproportionately thick or thin, draw your artwork to the correct size before mapping, or export guides from the Artwork Mapping dialog box and scale the artwork within your drawing program.
IMPORTING TWO-DIMENSIONAL ARTWORK
Imported two-dimensional artwork can be ungrouped, rotated, scaled, and moved. However, surface properties can not be applied or changed until the object is converted to a three-dimensional object. This also means that until an object has been converted to three dimensions, the Surface Properties dialog box will display the program's default colors and not the colors of the two-dimensional object.
ROTATING GROUPED OBJECTS
Grouped objects can be rotated only around the global x, y, and z axis.
BOUNDING BOX
The x, y, and z on the bounding box, discussed in Chapter 2 of the manual, are described as they apply to an object created in the Off-Axis Front view. If an object is created or imported in Off-Axis Back view, the location of the x, y, and z on the bounding box is opposite the location described in the example. If you rotate the object, the x, y, and z on the bounding box remain in their original location relative to the object. For example, if you turn an object upside-down, the dotted y is on top of the bounding box when you select the object.
GENERATING SEQUENCES
If you plan to import your sequence into Adobe Premiere, you must set the aspect ratio to avoid distortion within a sequence or between two linked sequences. To set the aspect ratio, draw a cube in Dimensions or import a square from your drawing program. The cube or square must have a width-to-height ratio of 4 to 3. It also must be larger than the largest bounding box in the sequence. When you generate your sequence make sure that the bounding box of the object being moved stays within the cube or square that defines the aspect ratio.
To revolve an object in place, it is best to generate the sequence in four 90° steps, rather than the three 120° steps recommended in the user guide. It is also recommended that you do not view the object using an Off-Axis view option. Viewing the object in an off-axis view makes the sequence appear to move up and to not revolve on a fixed point.
PREVIEWING CUSTOM BEVELS
Adobe Dimensions is not able to display previews in the Import or Extrude dialog box for imported bevels not included in the Adobe Dimensions bevel library.
BACKGROUND RENDERING
It is possible to switch to other applications while Adobe Dimensions is rendering. You can enable background rendering by holding down the Option key before selecting a render option from the View menu, or if you have selected the Wireframe Render, Draft Render, or Shaded Render option, you can enable background rendering by holding down the Option key when clicking Apply or OK in one of the Appearances dialog boxes. Background rendering cannot be enabled while rendering. Background rendering functions similarly to background printing of a large file. This means that you are able to work in other programs; however, the speed of applications in the foreground will be affected.
DETERMINING THE NUMBER OF BLENDS FOR HIGH-RESOLUTION OUTPUT
The quality of the output created in Adobe Dimensions is related to the number of blends used to render the artwork. Choosing the correct number of blends for your artwork is very important. Too few blends produces banding, or shade-stepping, in the printed output. Too many blends produces a file that is unnecessarily large and takes longer to print and to display.
The number of blends you need to avoid banding in your Final Render output depends on several variables, including
• the resolution and line screen combination of the output device you are printing to;
• the percent change in the colors being blended (that is, the percent difference between the object color and its shadow or highlight);
• the physical length of the blend, determined by the size of the object; and
• whether you are using diffuse or plastic reflectance properties.
Color and Lighting Rules
The maximum number of gray levels an imagesetter can produce is 256. As a general rule, if you are blending between 0% and 100% of a color, Adobe recommends using 256 blend steps. If you are working with a well-calibrated, linear imagesetter and a high quality printing press, you can usually obtain comparable results with about half as many blend steps.
If you are blending between a shorter range of color (say 40% magenta to 100% magenta), the number of blends that you need is reduced by the percent change in color. In this example, the difference between 40 % and 100% is 60%, so the number of blends is 60% of 256, or 154, blends (256 X .60 = 154). If you are blending between process colors, use the percent change in the color component (C, M, Y, or K) that undergoes the greatest change. For example, in the blend represented here,
Color Starting% Ending % Difference
Cyan 20 90 70
Magenta 40 0 40
Yellow 90 100 10
Black 0 0 0
the greatest percentage difference is in cyan, with a change of 70%. Thus, the number of blend steps needed is 70% x 256 steps = 179.
With objects created in Adobe Dimensions, the color change in the blend depends on the lighting and reflectance properties of the object. If you are using diffuse lighting and your object goes from being fully lit to being fully in shadow, the change in color is determined by the black ink. In this case, the color change is between the black (K) value of the object itself and the black value of the object in shadow, which is 100% minus the ambient lighting percentage. So, for example, if the ambient lighting is set to its default of .2 (i.e., 20%), the maximum change in black would be 100% - 20% = 80%, and the number of blend steps would be 205.
For plastic reflectance, blends occur in two stages: a blend from object color to the color in shadow (as described above), and then a blend from the object color to white (where white is 0% C, 0%M, 0%Y, and 0%K). The number of blends for the first stage is therefore the same as the number of blends required for diffuse lighting; the number of blends for second stage is simply the maximum value of the C, M, and Y components. The total number of steps needed for the blend is two times the maximum of these two values. This is because Adobe Dimensions divides the blends equally between the two blend stages.
Determining the best resolution/line screen combination
With most printers, increasing the screen frequency decreases the number of gray levels available to the printer. If the number of gray levels is less than the number required for your blend, the result is a posterized gradation. Before you create your artwork, find out what resolution and line screen will be used to print the artwork. These two numbers determine the number of gray levels the imagesetter can print.
The following table shows the maximum resolution/line screen combinations to use to achieve 256 levels of gray. If you know the line screen but the resolution hasn't yet been decided, use the table below to determine the minimum resolution needed to print that line screen. For example, if you are creating artwork for a publication that always prints at a line screen for 150, you need to print film at a resolution of 2400 or more to get 256 levels of gray. If you print at a lower resolution, you won't get 256 levels of gray and may see banding in your blends.
Imagesetter Recommended
resolution line screen
600 38
1270 79
2400 150
2540 159
3600 225
For other resolution/line screen combinations, use the following equation to calculate the number of grays you can reproduce.
Number of grays = [resolution (dpi) / line screen (lpi)]2
If you can't reproduce 256 levels of gray, use the equation to calculate the number of grays that you can reproduce, and use that number in place of 256 in the Color and Lighting Rules section to determine the maximum color change/ambient light combination you can use with your equipment.
The following chart gives the recommended number of blends for a 2-inch object filled with white. In each case, we assumed that the line screen and resolution could not be changed; therefore, to avoid banding, we adjusted the ambient light. (Increasing the ambient light decreases the percent change between colors.)
