Hướng dẫn sử dụng Coreldraw x5 - part 70 ppt

6. Move the polygon around if you like. Notice also that by applying a 2-point outline to the frozen lens object, background areas such as the grid the spanner is resting on become visible. Everything under the lens is now part of a group of vector objects— you can press CTRL+U now to ungroup the objects and individually recolor them if you like. Ill 22-2 Changing a Lens Viewpoint The Viewpoint option offers the chance to move a lens object but also to retain the view of the objects the lens was originally over. The Lens Viewpoint option lets you move a lens and keep the view inside the lens constant—like freezing a lens—but this option keeps the effect dynamic. When you check Viewpoint on the Lens docker, an Edit button appears. You then click-drag interactively to reposition the viewpoint of the lens effect either by using your cursor (indicated onscreen by an X) or by entering numeric values in the X and Y page position boxes. 674 CorelDRAW X5 The Official Guide Ill 22-3 The view seen through a lens object is dependent on object order on a layer—all objects layered below the lens object appear in the lens. When the Viewpoint is repositioned, you may find that an object might not appear visible. Arranging objects in back of the lens object causes them to be affected; arranging them in front of the lens object prevents the lens effect from changing them. The default viewpoint position of a lens effect is always the center of your object, but you can move it anywhere you like. After moving it, click the Edit button and then the Apply button on the Lens docker to set the new position. The Viewpoint option does not use the auto-apply lock feature. CHAPTER 22: Lens Effects, Transparency, Shadows, Glows, and Bevels 675 22 Lens object with Invert applied New viewpoint marker position Numeric entry boxes for viewpoint page position Edit/End button Using the Remove Face Option Remove Face is available for only a few types of lens effects and lets you specify whether other objects and the page background participate in the effect. By default, whenever a lens effect is applied, the background—your page, which is usually white—is involved in the effect. However, if the lens you are using alters colors—such as Custom color map—and you don’t want your background to be changed within the view seen through the lens object, choosing the Remove Face option leaves the background unaltered. Clearing Things Up with the Transparency Tool Transparency is an effect CorelDRAW users have leveraged for many years to illustrate scenes that have a very photorealistic look. The Transparency tool is quite different in use and in the effect you achieve than the Transparency lens. You have directions for transparency such as linear and radial, and also various operators (styles of transparency) available from the property bar to set how a partially transparent object interacts with objects below it. Any “look” from stained glass to a bleached-out overexposure is possible to create using the different operators. One thing is good to keep in mind when working with transparency in a design: this is the way you blend colors between objects. That’s it; your work doesn’t benefit from a totally transparent object—there has to be some influence from the object to which you apply transparency, and it’s usually color. Therefore, an alternative way to think about transparency is to think about color blending. One of the keys to accomplishing amazing artwork using the Transparency tool is the fill that a semitransparent object has; in addition to uniform fills, fountain and pattern fills can also take on transparency. You put fills and transparency together, and you’re talking seriously sophisticated compositions! Another key lies in how you approach a drawing in which you plan to feature partially transparent objects. To illustrate a real-world object such as a piece of jewelry, transparency plays a part—the gem in the jewelry, for example—but there will certainly also be nontransparent objects in such a drawing, so don’t overindulge in transparency when only certain parts of an illustration make the best use of this effect. In the next illustration, you can see what is today a fairly common button for a web page; it suggests glass. At left you can see a Wireframe view; not a lot of objects went into a fairly convincing drawing of a glass button. Combining use of the Transparency tool with your own designer’s eye, you can illustrate gases, smoke, fog, mist, and steam; you can also add reflections and highlights to your work to add detail, interest…and a touch of glass. 676 CorelDRAW X5 The Official Guide Ill 22-4 Using the Transparency Tool and Property Bar The transparency effects discussed next are applied using the Transparency tool located in the toolbox grouped with other interactive tools, shown here: Ill 22-5 When creating a transparency, you can set whether the fill and outline properties of objects are included in a transparency effect. Choose All, Fill, or Outline using property bar options. While the Transparency tool is chosen, the property bar displays all options to control the transparency effect. These options, as shown in Figure 22-7, are used together with any interactive markers surrounding the target object. Often, the most rewarding way to discover and gain control over a feature in CorelDRAW or any program is to dive straight in. The following tutorial might seem a little challenging because an explanation of the transparency options is provided on the fly, sort of like getting directions while you’re driving, but you might want the power of transparencies at hand right now, as we all do with valuable stuff! Follow along here to create a fairly realistic composition of a child’s marble; transparency will take care of the shading and the highlights. You can check out the Marble.cdr document to see and take apart the components at any time. CHAPTER 22: Lens Effects, Transparency, Shadows, Glows, and Bevels 677 22 Transparency tool White fill, linear transparency, Normal mode White filled group, uniform transparency, Add mode Linear fountain fill Creating a Dimensional Drawing Through Transparency 1. Create a circle (choose the Ellipse tool and then hold CTRL while you drag). Give it a bitmap pattern fill by first choosing the Interactive fill tool; choose Texture Fill from the Fill Type selector on the property bar, choose Samples from the Texture Library drop-down, and then choose the third (pinkish) pattern from the drop-down on the property bar. 2. Press CTRL+C and then CTRL+V to put a duplicate of the circle directly above the original. Click the black color well on the Color Palette to give this duplicate a uniform black fill. 3. Choose the Transparency tool. Choose Radial as the Transparency type from the property bar, and then choose If Darker from the Transparency operator list on the property bar. 4. Click-drag the interactive marker, the black one that shows the start of the radial transparency, and move it just a little toward 10 o’clock. Then click-drag the end marker (the white one) toward 4 o’clock until the shading of this semitransparent 678 CorelDRAW X5 The Official Guide FIGURE 22-7 Use the property bar to customize a transparency object. Click to edit a transparency fill. Transparency Type (identical to fill types) Transparency Operation (merge modes) Angle and Edge Pad Transparency Midpoint Apply Transparency to fill, outline, or both. Freeze Transparency Copy Transparency Properties Clear Transparency object lends to the underlying bitmap-filled object the appearance of light coming into the scene from 10 o’clock. This is a classic key lighting effect used by photographers, so the composition should look a little photorealistic now. Refer to Figure 22-8, because you were promised directions while you’re driving, and this figure is a roadmap! 5. Create a small white circle, about 1/10th the size of the circle. Fill it with white and then choose the Transparency tool. 6. Set the transparency type to Radial for the circle, and leave the Transparency Operator merge mode at the default of Normal. 7. By default, the Radial type of transparency produces the opposite effect than the one desired here: this object should serve as a highlight on the child’s marble; on the Color Palette, drag the black color well onto the end marker of the interactive transparency, and then drag white to the start marker. 8. Drag the end marker to just inside the circle object; doing this ensures that the object is 100% transparent at its edges, creating a perfect highlight object. Put it at the upper left of the marble drawing, and consider this a frenetic tutorial well done! Setting Transparency Properties If you have experience with CorelDRAW’s Interactive fill tool, you’re 99 percent of the way to mastering the transparency fill types with the Transparency tool. Because transparency isn’t the same as an object’s fill, the following sections take you through some unique properties. You’ll find wonderful design potentials you can leverage by choosing your transparency type according to what you need to design. CHAPTER 22: Lens Effects, Transparency, Shadows, Glows, and Bevels 679 22 FIGURE 22-8 Use the Transparency tool to create shading for simple objects that you want to look dimensional. Step 4Step 1 Result of steps 1–4 Step 7 Finished marble illustration Uniform Transparency Uniform transparency is the default for objects to which you assign transparency; the object will feature a flat and even transparency value. The way this semitransparent object blends with underlying objects is completely predictable. For example, if you assign a red rectangle and then a blue rectangle with 50% (the default transparency amount) and overlap them, yep, you’ll see violet in the intersection. The Uniform transparency type has no control markers over the object as other types do. Fountain Fill Transparencies Transparent objects that use any of the fountain fill direction types are an exceptionally powerful tool for illustration, as you’ll see in a moment. What governs the degree of transparency at the start and end points are the control markers, not only their position relative to the object underneath, but also the brightness value of the markers. Fountain fill transparencies are driven by any of 256 shades, from black to white. Let’s use the Linear transparency type; if you understand this type, all the others (Radial, Conical, and so on) will become obvious. When you click-drag using the Linear transparency on an object, the start marker is white, indicating full opacity, and the end marker is black, indicating no opacity at all. Here’s Trick No. 1 in creating an elegant fountain fill transparency: you can change the degree of opacity at the start and end points by using two methods, or a combination of the two: ● Reposition the start and end markers. If you position the markers way outside of the object, the transition between full and no opacity will be gradual, and the outermost parts of the transparent object will be neither completely opaque nor completely transparent. ● Change the brightness; the markers can have any of 256 shades of black. Let’s say you have the start and end markers exactly where you want them; you like the angle of the fountain fill transparency. But you don’t want the end (the black marker) to be 100 percent transparent. You click-drag a deep shade of black from the Color Palette and then drop it onto the black end marker. The end of the transparency then becomes mostly but not 100 percent transparent. Trick No. 2 is to choose the transparency object’s color to influence (usually to tint) the objects below the transparency object. Figure 22-9 shows an example: black paragraph text is on the bottom of the drawing page. On top of it is a rectangle. At left, the rectangle is filled with white, and a Linear fountain fill transparency is click-dragged from top to bottom. The text appears to be coming out of a fog. In the center, a 50% black fill is then applied to the rectangle, and a different visual effect is achieved—the paragraph text still looks like it’s in 680 CorelDRAW X5 The Official Guide a haze, but more of it is legible toward the top. At right, black is the fill for the rectangle, and now the top of the text is as illegible as in the white rectangle example, but a different artistic sense of drama has been achieved. You now know two different methods for shading with transparency fills of the fountain type: change the control markers and change the color of the transparency object. Property Bar Options for Transparency Effects Some CorelDRAW users prefer the hands-on controls of interactive markers, while others choose the precision offered by the property bar’s numeric entry fields and sliders; let’s look at what is available on the property bar when the Transparency tool is chosen and a target object is selected. In Figure 22-7 you saw the Midpoint slider, and the Angle and Edge Pad fields called out; here’s what they do. If no object is selected and you want to make any object partially transparent, the Transparency tool is a selection tool in addition to controlling the interactive markers. With the tool selected, click once to select the object to which you want to apply transparency, and then click-drag to add and set the control markers. ● Midpoint slider This slider controls where the 50% point in a transparency is located. It does not indicate where an object is 50% transparency, but instead sets a relative 50% break point, because as mentioned earlier, you can set the start and end markers to any brightness value you like. CHAPTER 22: Lens Effects, Transparency, Shadows, Glows, and Bevels 681 22 FIGURE 22-9 Use the marker positions, the marker brightness values, and the color of a transparency object to create interesting effects. Linear Transparency Start control marker (white) Midpoint End control marker (black) White transparent object 50% black transparent object Black transparent object Black text underneath ● Angle When you click-drag, for example, a Linear transparency, you might not get the angle exactly the way you’d like it. Use this box to set an exact angle for the transition. Setting 90º runs a Linear fountain fill from transparent at top to opaque at bottom, and the angle measurement decreases as you travel clockwise. ● Edge Pad Increase or decrease the “speed,” the contrast of the fountain transparency. The highest value is 49, at which the transition is so abrupt you could shave yourself with the edge between the start and end opacity amounts. By default, when you hold CTRL and drag a control marker for a fountain type transparency, you constrain the angle you’re setting in 15-degree increments. You can also straighten a crooked fountain transparency you’ve manually defined by CTRL+click-dragging. Here is a practical example of a Linear transparency used in an illustration to imitate the “glass icon” reflective look. In this illustration, the folder design has been copied and then mirrored horizontally. Then the Linear transparency is applied to the duplicate group of objects, from almost 100% opaque where it meets the original, to 100% transparent at the bottom. Transparency is good not only for simulating glass but also for simulating reflective objects. Ill 22-6 682 CorelDRAW X5 The Official Guide Additional Fountain Transparency Types You also have Radial, Conical, and Square fountain transparency types at hand when you design something you need to look more dimensional. The Radial type transparency effect is fantastic for making spectacular highlights—brilliant but soft-edged highlights you commonly see when sunlight hits a highly polished metal or smooth plastic object. A Conical transparency is good to use when you need a pie wedge–shaped area, and this, too, is good for simulating highlights and reflections. The Square transparency type might not prove useful on a day-to-day basis, but it’s very easy to create soft-edged highlights to use as windowpanes and other right-angle geometric areas you want to visually emphasize. Before covering the bitmap type fills—listed below the fountain transparency types on the property bar drop-down list—let’s take a detour in this documentation to explain transparency operations. Also called “merge modes” and “blend modes,” operations have an additional effect on all objects that have a transparency effect. Operations can get you out of a design predicament when a transparent object doesn’t seamlessly blend with objects below it. Using Transparency Operations (Merge Modes) The property bar has a list of modes for you to set how your transparency colors interact with the colors of underlying objects. These options further the visual complexity of semitransparent objects, and their use is for professional-level illustration work. For example, a red plastic drinking glass on a yellow tablecloth will show some orange through it due to the nature of colors that mix as light passes through the glass. However, the shadow cast by the nontransparent areas of the glass will not be the same shade of orange as the light we see through the glass, because light in the real world is subtractive, and the shadow in such a scene would be a deep, muddy orange, almost brown. But you don’t have to calculate light properties or material properties when you illustrate if you understand what the transparency operations do and then choose the operation appropriate for your illustration. The following definitions of merge modes describe the effect you can expect. Let’s say source is the top object that takes the transparency effect, the target is one or more objects below the transparency object that are overlapped by the transparency object, and the result is the color you see in your drawing in the overlapping areas. ● Normal Normal merge mode is the default whenever a new transparency effect is applied to an object. Choosing Normal at 50% opacity usually produces predictable color blends between the source and target objects; for example, a pure yellow object at 50% Normal opacity over a pure red object yields orange as a result in overlapping areas. Similarly and in traditional physical painting, a white source object produces a tint result over a pure color object (a pastel color), while a black source object produces a shade of the target object’s color (if you’re shopping for house paints, the salesperson will love this jargon). CHAPTER 22: Lens Effects, Transparency, Shadows, Glows, and Bevels 683 22 . transparency type might not prove useful on a day-to-day basis, but it’s very easy to create soft-edged highlights to use as windowpanes and other right-angle geometric areas you want to visually. a drawing in which you plan to feature partially transparent objects. To illustrate a real-world object such as a piece of jewelry, transparency plays a part the gem in the jewelry, for example—but. and highlights to your work to add detail, interest…and a touch of glass. 676 CorelDRAW X5 The Official Guide Ill 2 2-4 Using the Transparency Tool and Property Bar The transparency effects discussed