Adobe Illustrator CS4 bible phần 7 pptx

428 Putting Illustrator to Work Part II quite often, and they seem to have a good point at first. Upon further study, however, it becomes apparent that blends are quite different from gradients, both in form and function. You use gradients only as fills for paths. You can make gradients either linear or radial, meaning that color can change from side to side, top to bottom, or from an interior point to the outside. Every gradient can have as many distinct colors in it as you can create. Gradients are simply an easier way to create blends that change only in color, not in shape or size. CROSS-REF CROSS-REF For more on gradients, see Chapter 7. Blends, on the other hand, are a series of transformed paths between two end paths. The paths between the end paths mutate from one end path into the other. All the attributes of the end paths change throughout the transformed paths, including shape, size, and all paint style attributes. The major benefit is that you can blend multiple colors at one time. Blends can be incredibly flexible when it comes to creating photorealistic changes in color if you plan ahead. Changes to blends aren’t really changes at all; instead, they’re deletions of the trans- formed objects and changes in the attributes of the end paths. If you know what you want, blend- ing colors can take on an incredibly realistic look by changing the shapes of the blend’s end paths just slightly. But even more useful than creating realistic changes in color is blending’s capability to transform shapes from one shape to another (this is typically called morphing), as shown in Figure 12.1. With a bit of practice (and the information in this chapter), you can transform any illustration into another illustration. There’s a limit to the complexity of the illustrations that you can transform, but the limit is due more to the time it takes to create the blends than to limitations inherent in Illustrator. Because blends work on both stroke and fill attributes of objects, you can create some really excit- ing effects that aren’t possible by using any other technique, electronic or traditional. FIGURE 12.1 Blending to transform (or morph) a shape 16_345191-ch12.indd 42816_345191-ch12.indd 428 10/24/08 12:53:02 PM10/24/08 12:53:02 PM 429 Using Path Blends, Compound Paths, and Masks 12 Creating Path Blends Originally, Adobe marketed the Blend tool as a tool whose primary purpose was to transform shapes, not blend colors. Instead, designers used the tool for blending colors to create what were known as vignettes or what traditional artists called gradients. The Blend tool creates in-between steps in the area between two paths, where the paint style and shape of one path transform themselves into the paint style and shape of the second path. Version 8 of Illustrator dramatically enhanced the Blending function. The big change is that blends became live, or editable. This huge change allows users to change the color, shape, and location of the blend shapes. The blend instantly reblends to the new changes. Another great change is the capability to blend along a path. Although any blend takes into account both color and shape, I treat color and shape separately in this chapter because people using the Blend tool are often trying to obtain either a color effect or a shape effect rather than both at once. You use the Blend tool to create blends, which are a group of paths (commonly referred to as blend steps) that change in shape and color as each intermediate path comes closer to the opposite end path. Follow these steps to create a blend: 1. Using a shape tool, create a small (1-inch) vertical shape. This example uses a rectan- gle. For more on creating shapes, see Chapter 5. 2. With the Selection tool, click on the rectangle, press Alt (Option), and then drag a few inches to the right. This copies the path a few inches to the side. Press Shift as you drag horizontally to constrain the movement of the path. 3. On the left shape, change the fill and stroke to desired values. This example uses a fill of Black and a stroke of None. For more on changing the fills and strokes for shapes, see Chapters 4 and 5. 4. For the right rectangle, change the fill and stroke to desired values. This example uses a fill of White and a stroke of None. 5. Select the Blend tool by pressing W, click the top-left point of the left path, and then click the top-left point of the right path. This step tells Illustrator to blend between these two paths, and it uses the top-left points as reference. The Blend tool cur- sor changes from x to + in the lower-right corner. Illustrator creates a spine between the two end paths, which are now transparent. Figure 12.2 shows the resulting blend. 6. Press Ctrl+Shift+A (Ô+Shift+A). This deselects all previously selected paths. The default Blend Option creates smooth color between the two shapes. The blend consists of 256 paths, including the two end paths. In the example, each path is a slightly different tint of black. 16_345191-ch12.indd 42916_345191-ch12.indd 429 10/24/08 12:53:03 PM10/24/08 12:53:03 PM 430 Putting Illustrator to Work Part II FIGURE 12.2 This blend moves from black to white. Defining Linear Blends You create color blends by making two end paths, usually identical in shape and size, giving each path different paint style attributes, and generating a series of steps between them with the Blend tool. The more end paths you create, the more colors you can create. NOTE NOTE The examples in this chapter are easier to understand when you work in Preview mode. For more on Preview mode, see Chapter 2. Follow these steps to create a basic linear blend: 1. Draw a curved path with the Pen tool, filling and stroking it as desired. The example has a fill of None and a stroke of 2-point Black. 2. Alt+copy (Option+copy) the path to the right, filling and stroking the copied path as desired. The example gives the new path a stroke of 2-point Yellow. 3. With the Blend tool, click the path on the left and then the path on the right. Alternately, you can select both objects and then choose Object ➪ Blend ➪ Make. 4. Deselect all by pressing Ctrl+Shift+A (Ô+Shift+A) to see the result, as shown in Figure 12.3. NOTE NOTE The blend shown in Figure 12.3 demonstrates one of the hazards of creating blends — something often referred to as banding. See the sidebar on banding later in this chapter to learn what to do to reduce or eliminate banding. 16_345191-ch12.indd 43016_345191-ch12.indd 430 10/24/08 12:53:03 PM10/24/08 12:53:03 PM 431 Using Path Blends, Compound Paths, and Masks 12 You have a variety of ways to blend objects. Keep in mind these suggestions when blending objects: n You can edit blends by using the Selection, Rotate, or Scale tools. n You can perform blending with any number of objects, colors, opacities, and gradients. n You can’t apply blending with mesh objects. n You can’t edit the path (or spine, as it’s called) that the blend creates. n The fill of the topmost object is used when blending patterns. n When intermixing process and spot colors, the blend is colored with process colors. n When blending with transparent objects, the topmost object’s transparency is used. n You can blend symbols. n You can change the number of steps that Illustrator uses in the Blend Options dialog box. n Blends create a knockout with transparency groups. (If you don’t want this, change it in the Transparency panel by deselecting the Knockout Group option.) FIGURE 12.3 The final result is a linear blend. 16_345191-ch12.indd 43116_345191-ch12.indd 431 10/24/08 12:53:04 PM10/24/08 12:53:04 PM 432 Putting Illustrator to Work Part II Working with Blend Options Adobe has enhanced the Blending functions of Illustrator by making the Blend tool easier to use and faster and by adding a Blend submenu under the Object menu. The Blend options are Make, Release, Blend Options, Expand, Replace Spine, Reverse Spine, and Reverse Front to Back. With Illustrator’s Blend capability, you may not need to release a blend to change it. You can use the Direct Selection tool to select the end paths and edit the paths or change their color, and the blend instantly updates. Live Blending is the capability to change the shape or color of a blend and update it automatically. Using the Blend option The Blend Options dialog box lets you change the Spacing and Orientation aspects. Select the blend that you want to adjust, and either double-click the Blend tool or choose Object ➪ Blend ➪ Blend Options to open the dialog box to change the settings. Figure 12.4 shows the Blend Options dialog box. The three Spacing choices are Smooth Color, Specified Steps, and Specified Distance. The Orientation options are Align to Page and Align to Path. FIGURE 12.4 The Blend Options dialog box allows you to set up blends the way you want. These are the Blend options: n Smooth Color: This option automatically determines the best number of steps needed to make this blend look very smooth. n Specified Steps: This option lets you choose the number of intermediate steps you want in the blend. n Specified Distance: This option allows you to type the distance between steps. n Align to Page: This option runs the blend vertically or horizontally, depending on your page orientation. n Align to Path: This option runs the blend perpendicular to the path. 16_345191-ch12.indd 43216_345191-ch12.indd 432 10/24/08 12:53:05 PM10/24/08 12:53:05 PM 433 Using Path Blends, Compound Paths, and Masks 12 Blending multiple objects Illustrator has the capability to blend multiple objects in one step. Long gone are the days of blending, hiding, blending, hiding, etc. Select all the objects that you want to blend and then choose Object ➪ Blend ➪ Make or use the Blend tool to click all the objects that you want to blend. Figure 12.5 shows a blend that uses four different-shaped rectangles. To create this effect, I first drew four rectangles, each with a different fill. You need to use different fills in the objects to see a blend effect like this one. FIGURE 12.5 Blends can use multiple objects. Editing a blended object Blend functionality lets you change the colors of a blend without having to redo the whole blend. With the Direct Selection tool, select the path whose color you want to change in the blended shape. Choose a new fill and/or stroke color. The blend updates instantly with the new color. Another great aspect of Live Blend is the capability to edit the blend at any time and have it auto- matically update on the fly. As mentioned before, Illustrator creates a path, or spine, when you cre- ate a blend. With the Direct Selection tool, you can select an anchor point on the spine and move it. This changes the location of that point, and the blend updates accordingly. Now you can edit lines by adding, deleting, or moving any part of your blend, and it updates auto- matically. You can delete and add points or change the shape of a path with the Direct Selection tool. Figure 12.6 shows a figure before and after editing the blend. In this case, the meeple that begins the blend was modified in the lower blend by dragging the point at the top of his head up. 16_345191-ch12.indd 43316_345191-ch12.indd 433 10/24/08 12:53:06 PM10/24/08 12:53:06 PM 434 Putting Illustrator to Work Part II FIGURE 12.6 The original figure (top) and the edited blend (bottom) show how a simple modification can create a vastly different object. Releasing a blend If you want to redo a blend, you have to release it first by choosing Object ➪ Blend ➪ Release. This command eliminates the intermediate objects and leaves you with just the original ones. Expanding blends If you want to retain the intermediate objects, choose Object ➪ Blend ➪ Expand. Choosing Object ➪ Blend ➪ Expand expands the blend into a series of individual shapes. You can then move or edit these shapes independently of the other shapes. Replacing the spine The Replace Spine option allows you to make a blend follow a selected path. Follow these steps to apply this effect: 1. Create the blend as described earlier in this chapter. For example, create a blend that blends a mostly vertical ellipse into a mostly horizontal ellipse. 2. Draw a path in the shape that you want the spine of the blend to follow. In this case, draw a large diameter circle to use as the path for the blend. 16_345191-ch12.indd 43416_345191-ch12.indd 434 10/24/08 12:53:07 PM10/24/08 12:53:07 PM 435 Using Path Blends, Compound Paths, and Masks 12 3. Select the blend with the spine that you want to change and the path that you want to become the new spine. 4. Choose Object ➪ Blend ➪ Replace Spine. The blend updates automatically, in this case adding a new step, with the objects distributed evenly from their centers. Figure 12.7 shows before and after a blend has been applied to a path. In this case, the path used in the lower instance is a circle. FIGURE 12.7 This demonstrates how the original blend (top) is changed after applying Replace Spine (bottom). 16_345191-ch12.indd 43516_345191-ch12.indd 435 10/24/08 12:53:09 PM10/24/08 12:53:09 PM 436 Putting Illustrator to Work Part II Reversing the spine This menu option reverses the sequence of the objects that you’re blending. If you have a rectangle on the right blended to a circle on the left, choosing Object ➪ Blend ➪ Reverse Spine places the cir- cle on the right and the rectangle on the left. Reversing the spine flips the position of the shapes on the spine, as shown in Figure 12.8. Reversing front to back The Reverse Front to Back option reverses the order in which your paths were drawn when you created your blend. If you drew a small circle first and a large circle second, choosing Object ➪ Blend ➪ Reverse Front to Back places the small circle underneath and the large circle on top, as shown in Figure 12.9. FIGURE 12.8 Reversing the spine changes the original (top) by swapping the position of the shapes (bottom). 16_345191-ch12.indd 43616_345191-ch12.indd 436 10/24/08 12:53:09 PM10/24/08 12:53:09 PM 437 Using Path Blends, Compound Paths, and Masks 12 FIGURE 12.9 Reversing the spine front to back changes the stacking order of the original (top), creating the effect shown (bottom). Using nonlinear blends End paths on a blend with two endpoints (linear segments) used to make blends don’t have to be just horizontal or vertical. And when you create multiple color blends, you don’t have to align the intermediate end paths the same way as you align the end paths. Careful setup of intermediate blends can create many interesting effects, such as circular and wavy appearances, all created with straight paths. 16_345191-ch12.indd 43716_345191-ch12.indd 437 10/24/08 12:53:09 PM10/24/08 12:53:09 PM [...]... 12. 17 shows how to use shape blends to create the glowing surface of a lit object — in this case, a light bulb The key to successfully achieving this effect is to draw the shape first and then use a copy of the exact same path for the highlights The relative locations of anchor points stay the same, and the number of anchor points never changes 4 47 12 Part II Putting Illustrator to Work FIGURE 12. 17. .. 4 To change the number of steps, choose Object ➪ Blend ➪ Blend Options When blending black to white, Illustrator automatically uses 255 steps When blending other colors, Illustrator automatically chooses the best amount Feel free to experiment with changing the number of steps 441 12 Part II Putting Illustrator to Work You can create radial blends with almost any object Figure 12.13 shows a radial blend... like this: (300/53) × (300/53) = 5.66 × 5.66 = 32 A 400-dpi printer at a line screen of 65 has the following formula: (400/65) × (400/65) = 6.15 × 6.15 = 38 A 600-dpi printer at 75 lines per inch uses this formula: (600 /75 ) × (600 /75 ) = 8 × 8 = 64 Sometimes, you may want to reduce the number of blend steps in a blend from the default because either your printer can’t display that many grays or the distance... the JPEG file TIP 451 12 Part II Putting Illustrator to Work FIGURE 12.21 These 3-D stars are blended together and are still fully editable Airbrushing and the Magic of Stroke Blends B lending can create effects that are usually reserved for bitmap graphics functions, such as the Glow, Drop Shadow, and Feather effects in Illustrator or the Layer Effects in Adobe Photoshop, but without the limitation... shown in Figure 12. 27 (A section later in this chapter discusses reversing path directions.) In most cases, you get the desired results with holes only if the outermost path contains all the holes As a rule, Illustrator uses the topmost objects to poke holes out of the bottommost objects If you want holes to overlap, ensure that the holes are above the outside border NOTE FIGURE 12. 27 This figure shows... Calculating the number of steps Whenever you create a blend, Illustrator provides a default value in the Specified Steps text field of the Blend Options dialog box that assumes that you want to print your illustration to an imagesetter or another high-resolution device capable of printing all 256 levels of gray that PostScript allows 439 12 Part II Putting Illustrator to Work FIGURE 12.12 Lines and rectangles... only five colors in the blend, thus creating five bands If you place each of the end paths on one side of a 17- inch span, each created blend step takes up the 5 points of width of the stroke, making each shade of gray 5 points wide If you make the color on the left 10% Black instead of 100% Black, Illustrator creates only 26 color steps between the two end paths So, to avoid banding, use the recommended... points, and use the same color as the fill 7 Choose Object ➪ Blend ➪ Make to blend the two objects 8 Choose Edit ➪ Paste in Front or press Ctrl+F (Ô+F) to place a copy of the original object on top of the blended object 9 Click outside the objects to deselect them Figure 12.24 shows an example of how a softened edge looks when zoomed in to 800% 455 12 Part II Putting Illustrator to Work FIGURE 12.24 Zooming... look, create unlit portions of neon by using darker shading with no reflective glow FIGURE 12.25 A neon candle is a good example of how you can use two blends to create an interesting effect 4 57 12 Part II Putting Illustrator to Work Another interesting effect that you can create that’s similar to the neon effect is a backlighting effect You can accomplish backlighting effects by creating a glow for an... difficult to get the results you want with complex-shape blends 445 12 Part II Putting Illustrator to Work One function that you can perform to improve the blend involves adding or removing anchor points from the end paths Even if you select the same number of points and those points are in similar areas on each path, Illustrator may not give you an acceptable result The Add Anchor Point and Delete Anchor . 10/24/08 12:53:04 PM10/24/08 12:53:04 PM 432 Putting Illustrator to Work Part II Working with Blend Options Adobe has enhanced the Blending functions of Illustrator by making the Blend tool easier to. all created with straight paths. 16_345191-ch12.indd 4 371 6_345191-ch12.indd 4 37 10/24/08 12:53:09 PM10/24/08 12:53:09 PM 438 Putting Illustrator to Work Part II NOTE NOTE End paths that cross. formula: (400/65) × (400/65) = 6.15 × 6.15 = 38 A 600-dpi printer at 75 lines per inch uses this formula: (600 /75 ) × (600 /75 ) = 8 × 8 = 64 Sometimes, you may want to reduce the number of blend