Hướng dẫn sử dụng Coreldraw x5 - part 59 potx

goal of copying its vanishing point position. For this command to be successful, you must have at least one other extrude effect applied to an object and in view. After the vanishing point has been copied, the property bar indicates the object’s vanishing point as VP Locked To Page. ● Sharing vanishing points Choosing Shared Vanishing Point enables you to have multiple objects share the same vanishing point, but you must have applied at least an initial extrude effect to your objects before using this command. Immediately after you choose this option, your cursor changes to a vanishing point targeting cursor, which signifies that you now target any other extruded object for the purpose of creating a common vanishing point position for multiple objects. This creates a similar effect to copying vanishing points, but the overall effect is that every object on the page is in the same scene. The objects are positioned in different areas, but it’s one big, visually integrated scene. Shared Vanishing Point can be repeated for as many objects as you like. When multiple objects share a vanishing point, they can be repositioned anywhere on your document page, and the perspective on the 3D object updates to maintain the relationship of a common vanishing point. Figure 19-5 shows the results of setting up a shared vanishing point arrangement with four objects. The figure has been retouched (you can’t view more than one vanishing point at a time) to show the converging point for all the objects’ sides, their depth aspect. ● Setting a relative position for vanishing points The Page or Object vanishing point option in the property bar is used to toggle the measurement state of object vanishing points between page and object. While the option is inactive (meaning the button is not depressed), the vanishing point position boxes enable you to specify the vanishing point relative to your page origin—a value determined either by the lower- left corner by default or by the zero markers on your ruler origin. While the option is active (the button is depressed), the center of your currently selected object is used as the measurement value, which changes according to the object’s page position. You will see this most noticeably if you have a depth on an object of more than 40 and drag the object around the page with the Pick tool. The extrude group actually changes to reflect different vanishing point views. Setting 3D Rotation Until now, the extrudes you’ve created and read about have been based on the control object facing you; this is a good beginning point in your 3D experience, but it’s not always the most visually interesting of poses for your 3D objects. You can rotate extruded objects; the extrude group follows and aligns perfectly with the control object, and you have two ways to perform 3D extrude rotations: via the property bar and with the interactive control handles. Create an extrude group of objects, and then let’s begin with the precise, noninteractive method of rotation you access through the property bar when the Extrude tool is chosen and an object is selected. 564 CorelDRAW X5 The Official Guide The Rotation pop-up menu offers a proxy box that you use by click-dragging on the 3, as shown next. As you drag, a very faint yellow line appears on the 3, indicating the current rotation of the object and the proposed new rotation once you release the mouse button. You might not always get the exact look you need using this technique because of the position of the object’s vanishing point—your experience can be similar to levering an object seesaw- fashion when the pivot point (the fulcrum) is 15 miles away! To avoid imprecision, you can click the toggle button labeled in the next illustration to move to a number field display of the X, Y, and Z rotational values (see the following sidebar). The value fields have spin box controls that increase and decrease the values by 5; you probably want to enter values manually, because a single degree of rotation can be quite significant, considering only 201 of them are in this pop-up box. If at any time you’ve gotten too deep in this 3D rotation CHAPTER 19: Extruding Objects 565 19 FIGURE 19-5 These four objects share the same vanishing point, applied using the Shared Vanishing Point command. Shared vanishing point position stuff, clicking the “undo” curved arrow icon on the lower left of the selector, shown here, resets all rotation values to zero. 566 CorelDRAW X5 The Official Guide Extrude Rotation button Resets rotation to zero Toggle display in selector Rotational Directions in 3D Space The creative rewards of knowing how to extrude and rotate objects in CorelDRAW require that you learn how to navigate in 3D space as you would in any true modeling program such as Cinema 4D, Poser, or 3D Studio. Directions in space are measured much the same as on a CorelDRAW page: positive X values (measuring width) move to the right, positive Y values (height) travel bottom to top, and the values of depth (Z) travel from back to front. Rotation direction travels positive in a counterclockwise direction, and this might take some familiarization to better use your time. Fortunately, you have an excellent mnemonic device at hand, literally, your right hand. Modeling usually uses the right-hand coordinate system: stand in front of a mirror if you don’t want your hand to cramp, face your palm upward, and then extend your forefinger to your right. This is the X measurement of 3D space, and X rotation travels counterclockwise around your forefinger. Now point your middle finger straight up to indicate the positive motion along the Y axis. The rotation of an object along Y is also counterclockwise. Point your thumb at yourself. Z motion travels toward you, and rotation along Z is counterclockwise, following the curl of your fingers. Therefore, when you want to rotate a CorelDRAW extruded object so its top is leaning toward you, this is the X axis, your forefinger. You enter positive values in the Drag Using the Rotation Tools You don’t have to use the rotation pop-up box on the property bar to rotate an extruded object: you can define a degree of rotation along the X, Y, and Z axes of any object by click- dragging the object directly. To do some manual rotation, the object needs to be extruded and first put into Editing mode—you can double-click on the extrude group of objects with the Pick tool to put the object into Editing mode, and then a second click exposes the control CHAPTER 19: Extruding Objects 567 19 X field in the pop-up box. If you want the left side of the extruded object to face you, this is your middle finger, and you enter positive Y values in the pop-up box, as shown in this illustration. Overall, the best teacher is experience, particularly with manipulating your view of a 3D object in CorelDRAW. Set aside some quality time, and you might even be pleasantly surprised by some of your errors! handles shown here. Before you leap in, read on for an explanation of what the interactive controls do and what you do with them to achieve the desired result. While either Back Parallel or Front Parallel is selected, extrude rotation controls are unavailable; parallel extrusions have no vanishing point, so there’s nothing to pivot with. Also, when the vanishing point is locked to the page, extrude rotation cannot be performed. When an object is rotated, the vanishing point controls on the property bar cannot be used, mostly because mathematically, the vanishing point is nowhere near your drawing page! If you need to adjust the vanishing point of an object, you must work backwards; on the Extrude Rotation pop-up panel on the property bar, click the Reset Rotation icon. Then the vanishing point options and controls become active (and your object is no longer rotated). Rotating an Extrude Effect Because a rotated extrude graphically describes an object more completely than a face-front view, the following tutorial will come in handy when you’ve extruded an object that has some built-in visual interest. Extrude something interesting now, and let’s take the manual, interactive rotation feature out for a spin. 568 CorelDRAW X5 The Official Guide Circular (Z axis) rotation cursor Extrude vanishing point marker Rotation reference markers X and Y axis rotation cursor X axis rotation cursor Y axis rotation cursor Putting a New Spin on an Extruded Object 1. With the Pick tool, double-click the extrude group or the control object, to expose the editing handles. Alternatively, you can use the Interactive extrude tool to select the object, and it’s immediately put into Editing mode. 2. Single-click the extruded portion a second time. The interactive rotation markers appear, and circular guides surround the effect. The inside and outside areas of this circular area determine the tool’s cursor state. 3. Move the cursor outside of the green dashed circle, and notice that it changes to the rotation cursor. This cursor is used to rotate the face of the object, the Z axis, counterclockwise and clockwise. Dragging right and down creates a clockwise rotation, and left and up rotates the face of the object counterclockwise. 4. Move the cursor inside the green dashed circle area, and it changes to the X/Y axis rotation cursor. Using this cursor is a lot like using an onscreen trackball; you just drag in any direction to simultaneously rotate the X and Y axes of the extrude object. It’s fun, you can see the vanishing point move to reflect the new aspect of the object, and it’s also not as precise as it could be when you only want to, for example, rotate the object along the top-to-bottom (Y) axis. 5. Release the mouse button for a moment and then hold CTRL. Then click-drag upward (downward is okay, too); you’re now constraining rotation to the X axis of the object. 6. Release the mouse button again and then hold CTRL. Now click-drag left or right; you’re constraining rotation to the Y axis of the object and not touching the X axis rotation. 7. When the amusement has worn thin or your task is accomplished, click a blank space on the document page way outside of the interactive rotational cursor area to deselect the effect. The cursor returns to the normal extrude cursor state. You’ve just completed manually rotating an extrude object. After an extrude effect has been rotated, you can still adjust the extrude depth of the effect, but not the vanishing points. Adding Lights Adding lighting to an extruded object can spell the difference between an effect and a piece of artwork that truly attracts a viewer with its realistic appearance; many of the figures in CHAPTER 19: Extruding Objects 569 19 this chapter use the Lighting option. To access the lighting controls, click the Extrude Lighting button on the property bar while an extrude effect is selected, as shown here: Working with the Options in the Lighting Control Window Three independent light sources can be activated, positioned, and adjusted for intensity and for whether all of the control object’s colors are used in the extrude group (the Use Full Color Range option). These lights are unidirectional; they can be positioned, but not aimed as you would a real flashlight or spotlight. Light intensity is set on a light-by-light basis between 0 and 100 percent by using the slider control when each is selected. One of the nice things about setting up light intensity and position is that response is immediate—there is no Apply button, and your object’s light changes as you make changes in the control window. When you first open the Extrude Lighting control window, all lights are inactive. To activate a light, click one of the three Light Source buttons—the numbering is for your reference; it’s just a label. There is nothing special about light 3 versus light 1, for example, in any of its properties. Once a light button is clicked, a circle with the light’s number inside appears in the front, upper-right position on a 3D grid surrounding a sphere, which represents the extrude object (see Figure 19-6). The lights themselves aren’t visible on the drawing page, but the lighting effect you define displays highlights and shaded areas on your extrude object, particularly evident when the sides of the control object are curved. The light sources can be posed by adding them to the grid and then dragging them—there are 16 possible positions for lights; some of the positions can create very interesting “edge lighting” on your object. Every time you activate a new light, it appears on the grid in the default position of front, top, right. This means that if you click to activate two or three Light Source buttons in succession without first moving them, you’ll stack them on top of each other and wind up with one extremely intense light source on the object. When this happens, drag the individual lights to reposition them at different points. 570 CorelDRAW X5 The Official Guide Extrude Lighting Light Source buttons Active, positioned light A selected light is shown as a black circle in the preview; unselected lights are shown as white circles. Lights set to brightness levels less than 100 percent appear in shades of gray. As these light sources are dragged around the 3D grid, they automatically snap to line- intersection points on the grid. You cannot position lights at the back-mid-center or back- center-bottom position, but this is not really a creative limitation, because lights in these positions would not significantly contribute to the shading of the extrude shape. There is no option to set the color of lights; all lights cast white. If you want a spotlight effect, read Chapter 22 on lens effects for techniques on shading objects with color. Adding and Editing Extrude Lights The following tutorial obliges you to put on your stagehand cap as you work the lights in a scene, adding them to the extrude object’s properties and learning how to position them and turn the wattage up and down. Working with Extrude Light Options 1. Create a color-filled object and apply an extrude effect to it. 2. Using the Interactive extrude tool, click the Extrude Lighting selector in the property bar to open the Light Source option. CHAPTER 19: Extruding Objects 571 19 FIGURE 19-6 The 3D grid represents light positions relative to the selected extrude object. Light source set to less than 100% intensity Selected light source Light sources align to grid intersections. Default light source position Sphere represents the extrude object. Unselected light source 3. Click the Light Source 1 button, and a light source symbol appears in the upper- right-front corner of the grid, shown as a black circle numbered 1. The Intensity slider becomes active; Light Source 1 is now active, and the colors of your extrude effect are altered (brightened and possibly a little washed-out) to reflect the new light’s contribution to the extrude effect. 4. Drag the symbol representing Light Source 1 to a different position on the 3D grid; notice how the coloring of the effect changes in response to the new lighting position. 5. With Light Source 1 still selected, drag the Intensity slider to the left approximately to the 50% position, and notice how the color of the object becomes darker and more saturated. 6. Click the Light Source 2 button to activate it. Notice that it appears in the same default position as the first light source, and the symbol representing Light Source 1 is gray, indicating that it is not selected and it is not at 100% Intensity. When an unselected light is at 100% Intensity, the symbol is white. Drag Light Source 2 to a different grid position—in classic scene lighting, a secondary light of, say, 50% of the main light’s intensity, is usually positioned directly opposite the main light to make objects look rounder, deeper, and overall more flattering with more visible detail than using only one light source. 7. Click the activation buttons for Light Sources 1 and 2 to toggle them off, and the color of the extrude object returns to its original state. To finish editing lights, click anywhere outside the Extrude Lighting selector. Occasionally in your design work, you might like the perspective you’ve created for the face of an extrude object, but might not need the extruded side, the extrude group of objects. You can remove an extrude effect from an object and keep its perspective and position on the page by clicking on the extruded portion of the effect and choosing Effects | Clear Extrude. You can also use the Interactive extrude tool by clicking the Clear Extrude button in the property bar. Controlling Light Properties Two additional options available when you’re using lighting have the following effects on your extrusion: ● Lighting intensity As mentioned in the previous tutorial, the Intensity slider determines the brightness of each light. While a light is selected, the range can be set between 0 and 100%; higher values cause brighter lighting. 572 CorelDRAW X5 The Official Guide Extrusion Color Use Object Fill Use Solid Color Use Color Shading Fountain fill control object Object Fill Solid Color Color Shading Bevel Color options ● Full color range Below the Intensity slider you’ll find the Use Full Color Range option, which directs your display to use the full gamut of colors when coloring the surfaces of your original object and its extruded portion. Gamut is the expressible range of colors available to CorelDRAW, which depends on the color mode (see Chapter 17) of the original object and the extrusion. When working in CMYK process or RGB color, you might find the shading on an object to have too much contrast; the lighting might look too harsh and might create washed-out surfaces. The remedy then is to uncheck Use Full Color Range; the gamut of colors is then limited, and the dynamic range of available colors becomes narrower. You just might wind up seeing areas that are hidden in deeply shaded zones when Use Full Color Range is not checked. Setting Extrude Color In addition to shading an extrude group using lighting, you can further embellish and draw out photorealistic qualities by using color options for the extrude. You might need to perform some technical illustration with extrude objects, and you might need cross-hatching in addition to lighting, for example. This is when you turn to the Extrusion Color option on the property bar; you have three different ways to shade an extrude group: object fill color, solid color, or color shading (much like a fountain fill transition from one color to a different color). In the Color control window, shown next, you can see the various modes you can use when you click the property bar Extrusion Color button. CHAPTER 19: Extruding Objects 573 19 . around the 3D grid, they automatically snap to line- intersection points on the grid. You cannot position lights at the back-mid-center or back- center-bottom position, but this is not really a creative. Extrude tool is chosen and an object is selected. 564 CorelDRAW X5 The Official Guide The Rotation pop-up menu offers a proxy box that you use by click-dragging on the 3, as shown next. As you drag,. want to, for example, rotate the object along the top-to-bottom (Y) axis. 5. Release the mouse button for a moment and then hold CTRL. Then click-drag upward (downward is okay, too); you’re now constraining