Tài iệu Photoshop cs5 by Dayley part 100 pptx

When you roll, rotate, or otherwise change the position of a 3D object, you are simply changing your view of it, not its positioning relative to the scene it was created in.. FIGURE 22.1

Your image doesn’t have to be in grayscale for this to work Photoshop uses the green channel to create a

depth map n

This type of 3D object is great for creating textures or another unique look for an image file They also can be used to create planes from elevation maps or to save and recreate planes from one 3D modeling file to another A simple image file can quickly become a mountain range, as seen in Figure 22.15

FIGURE 22.15

Using an image to create a depth map can quickly create interesting planes

Creating a 3D volume

The 3D volume option is used to create 3D objects out of image files that are slices of 3D objects, such as several DICOM files that are created by taking slices out of the center of an image Using this option allows you to create a 3D object from the image layers that can be moved, manipulated, and viewed from all angles, giving you a versatile way to view these medical images

Creating 3D Objects in the Layers Panel

The layers of a 3D object are more complicated than most images When you open a 3D object in Photoshop, unless that object doesn’t contain any textures at all, you have at least one sublayer listed under a textures heading On top of that, every filter you can add or edit you can make to a 3D object that involves the Layers panel in one way or another It doesn’t take very many changes

to add several layers to a 3D file or composite Don’t panic yet: Like a well-organized filing cabinet, the Layers panel is a clean and efficient way to organize your effects and filters

Figure 22.16 shows the Layers panel after creating a ring by using the 3D shape from the layer option The thumbnail of a 3D layer is distinctive It includes the icon of a three-dimensional cube

in the corner in addition to the thumbnail of the actual 3D object This indicates that the 3D menu

FIGURE 22.16

A 3D layer in the Layers panel

Notice the sublayers The primary sublayer is named Textures, and underneath it is another layer labeled Background This layer is the texture that has been applied to the 3D mesh to give it surface area and color It is named Background because I didn’t bother to change the name of the

back-ground layer before I created a 3D object from it This layer is actually an embedded file Double-clicking this layer opens the background layer as a separate two-dimensional file that I can change and rename if I want I also can add more textures to this object, which show up as additional lay-ers under the texture sublayer Each of these textures can be opened and edited individually

Cross-Ref

Editing textures is a primary reason to bring a 3D object into Photoshop I cover this aspect of 3D objects in

greater detail in Chapter 24 n

Manipulating 3D Objects

Imagine that you are standing in a room As you move in a straight line left to right, you are mov-ing along the X-axis If you were to jump up and down in place, you would be travelmov-ing along the Y-axis This is a two-dimensional plane, in which coordinates can be given with two numbers: an

X location and a Y location When you work with a two-dimensional file in Photoshop, you are working with an XY plane To add the third dimension, the Z-axis is added, creating depth to the

XY plane To move along the Z-axis you would walk front to back within the room

The 3D tools in Photoshop allow you to move 3D models within all three of these planes If you are already familiar with any 3D modeling software, you will find the tools used in Photoshop familiar Photoshop has designed its manipulation tools to a very standard look and feel If you have never used 3D tools, you will find that they are fun and easy to use Jumping in and working with them as we introduce them to you in this chapter is the best way to familiarize yourself with them very quickly

As you work with your 3D model, keep in mind that your final product in Photoshop will be a two-dimensional view, not a 3D scene or animation This helps you keep in perspective what you can accomplish in Photoshop and how to do it

Understanding static coordinates

If you are familiar with 3D modeling software, you should be aware of one important difference in Photoshop The 3D tools in Photoshop change the selected 3D layer, not the 3D scene When you roll, rotate, or otherwise change the position of a 3D object, you are simply changing your view of

it, not its positioning relative to the scene it was created in Being able to manipulate your 3D object allows you to make changes to its texture and place it in a composite that eventually becomes a two-dimensional image

That means that the X, Y, and Z planes remain static Whether you are manipulating a 3D layer or the camera, X and Y are always side to side and up and down, and Z is always depth Just imagine that you are looking at the 3D objects through a window that doesn’t move You can move the 3D objects around behind the window, but you can’t go into the room and walk around among them like you can in a standard 3D modeling program

Using the 3D object tools

The 3D object and camera tools are located in the Toolbox, as shown in Figure 22.17 When you select the active tool by clicking it or hitting K on the keyboard, the Options bar changes to show not only the options that are available for the tool, but all the other 3D object tools, as shown in Figure 22.18 These tools are used to move your object through 3D space

FIGURE 22.17

The 3D tools

Object Rotate tool Camera Rotate tool

FIGURE 22.18

The options bar for the 3D object tool

Tool

presets Rotate Drag Scale Save current view

Delete currently selected view Home (return to initial object position)

Roll Slide

The Home button

The first button in the options bar is the Home button At any time while you are manipulating your object, you lose it in “outer-space,” or just feel as if you’ve contorted its position beyond repair, you can hit the Home button to bring your object back to its initial position

Tip

It is incredibly difficult to explain moving an object through 3D space in a book with still shots The quickest

way for you to understand what I am trying to teach you is for you to use the tools in conjunction with this

book Create a quick 3D object by opening a new document, choosing 3D ➪ New Shape from Layer, and

choosing a shape from the menu An irregular shape, such as the hat, is the best for seeing the difference that

moving it makes n

Turning 3D objects around a central point

Turning a 3D object around a central point is done by using tools to rotate or roll that object

Rotating or rolling an object turns and skews it around the X-axis, Y-axis, or Z-axis While using the Rotate and Roll tools, your object moves around a center point, which never changes position

Changing an object’s orientation is the most obvious reason to use the Rotate and Roll tools But you also can change the lighting on your object As you move your object, notice that if you have a light placed in your scene, the lighting changes on your object

Another use for the Rotate and Roll tools is checking the texture of your object and making sure it

is the way you want it, especially if you made any changes to it in Photoshop You can select the Home button at any time to return your scene to its original settings

You can turn a 3D object around a central point using the Rotate and Roll tools, or you can enter the orientation numerically in the options bar

Rotating a 3D object

Using the Rotate tool rotates the 3D object around the X-axis and Y-axis The X-axis is a line run-ning side to side through the center of an object Like a hot dog turrun-ning on a roasting stick, if you rotate your object only on the X-axis, the top of the object rotates toward you or away from you

The Y-axis runs up and down through the center of your object As you rotate your object around the Y-axis, the sides of the object move toward you or away from you

Click and drag back and forth across your 3D object to rotate it along the Y-axis or drag up and down to rotate it along the X-axis, as shown in Figure 22.19 You can constrain the rotation to either the Y-axis or the X-axis by holding down the Shift key as you drag in the appropriate direction

As you manipulate your 3D object using the 3D tools, you notice that the 3D Axis Widget (shown in Figure

22.19) also moves in relation to the position of the 3D object I show you how to use the widget to manipulate

a 3D object later in this chapter n

FIGURE 22.19

Rotating an object around both the X-axis and Y-axis

Rolling a 3D object

Rolling your object around the Z-axis is a similar concept to rotating your object around the X-axis

or Y-axis Visualize a line running from front to back through the center of your object, allowing it

to roll left to right and back again You can roll your object around the Z-axis by clicking and drag-ging back and forth with the Roll tool, as seen in Figure 22.20

Tip

Although you can quickly skip through the 3D object tools by repeatedly pressing K, you also can use the

Alt/Option key to temporarily change the Rotation tool to the Roll tool, and vice versa n

FIGURE 22.20

Rolling an object around the Z-axis

Moving a 3D object through 3D space

Dragging or sliding a 3D object moves it to a different location in your 3D workspace Moving your object allows you to place it in the desired position so you can create composites by adding a photo background or other 3D objects You also may want to move an object to adjust the lighting

or change the perspective

Dragging a 3D object

Dragging moves the object around the XY plane and is visually similar to using the Move tool to move a selection in a regular image file You can drag your object by selecting the Drag tool in the options bar or the Toolbox, as seen in Figure 22.21

FIGURE 22.21

Using the Drag tool

Tip

You can toggle between the Drag and Slide tools by holding down the Alt/Option key n

Sliding a 3D object

Sliding moves the object along the XZ plane, so you can move it side to side, just as you can with the Drag tool, or in and out along the Z plane As you move your object toward you or away from you along the Z plane, it looks very similar to scaling, or resizing, your object, as shown in Figure 22.22 Although it looks the same, when working with 3D, sliding an object is a very different effect from actually making the object bigger or smaller, just as walking away from an object in real life doesn’t change its actual size, just your perspective of it

When you have the Drag or Slide tool selected, you can change the position of your 3D object numerically by entering values in the X, Y, or Z indicators in the options bar

FIGURE 22.22

Using the slide tool

Scaling a 3D object

Scaling a 3D object in Photoshop is very similar to using the Transform tools to scale an image or selection By selecting the Scale tool, you can click and drag across your object to make it bigger or smaller, as seen in Figure 22.23 As you change the size of your 3D object by using the Scale tool, the proportions of the object are automatically maintained By holding down the Alt/Option key while you click and drag, you can adjust the object non-proportionally by making it taller or shorter If you hold down the Shift key, you can make your object wider or narrower

When you have the Scale tool selected, you can change the size numerically by entering values in the X, Y, or Z indicators in the options bar This is usually a better way to scale your object dispro-portionately You also can change these values by scrubbing across the letter that applies to the value you want to change

FIGURE 22.23

Use the Scale tool to make 3D objects larger or smaller

Changing positions and saving a view

As you manipulate a 3D object, you can change the position of it to several presets, as shown in Figure 22.24 When you change the position of your object using the menu, you lose any position changes you have already made to it

If you’ve created a position that is different than any of the presets, you can save the position by clicking the Save button and naming the new position It is then added to the list of presets, and you can access it at any time You can delete the view by selecting it in the drop-down menu and clicking the garbage can