Tài iệu Photoshop cs5 by Dayley part 106 pptx

Using Photoshop Tools to Change the Appearance of a 3D Layer IN THIS CHAPTER Using 3D Paint mode Adding image adjustments to 3D objects Creating great composites In the last two chapte

Using Photoshop

Tools to Change

the Appearance

of a 3D Layer

IN THIS CHAPTER

Using 3D Paint mode Adding image adjustments to 3D objects

Creating great composites

In the last two chapters, you learned how the 3D workspace in

Photoshop functions to allow you to create, manipulate, and change

the look of 3D objects by changing their color, texture, and lighting

In this chapter, I show you how to integrate 3D objects into the Photoshop

workspace, using the tools you are probably more familiar with to paint over

your 3D objects and create adjustments, styles, and filters

The last section of this chapter walks you through some very complex

exer-cises that demonstrate some of the tools and techniques that can be used to

create a successful composite with 3D objects and images At this point, you

should be familiar with all the techniques used to create these composites,

but completing these exercises gives you practice using these tools and

shows you how they can work together

3D Paint Mode

You can grab a paintbrush in Photoshop and start slapping paint on your 3D

objects The paint conforms to the 3D object because even though you are

looking at your 3D object, you are changing the texture file, which is

wrapped around your 3D object This gives you the distinct advantage of

being able to change areas of the texture as it is mapped to your object,

instead of trying to guess where to paint in a flat, rectangular texture file

You can paint color onto your object, of course, but you also can paint

tex-Before I show you how to use the 3D Paint tools, I show you options for selecting areas of your object to paint on and hiding areas of your object that you want to protect These options in Photoshop are definitely a little rough around the edges (literally as well as figuratively); still, they can be useful

Hiding areas on a 3D object

You can create selections on a 3D image using the Selection tools just as you can with a two-dimensional image The problem is that the selections you create are two-two-dimensional selections, and they won’t conform to the 3D object You can see in Figure 24.1 that, after creating a selection around the hat, I moved the hat The selection didn’t move with it You can use the Selection tools

to make changes to 3D objects, but be sure that your object is placed just how you want it to be viewed, because the changes don’t extend to unseen areas of your object

FIGURE 24.1

The Selection tools are two-dimensional

You can, however, use the Selection tools to select paintable areas of your object or to hide areas that you want to protect These tools also are affected by the fact that selections are two-dimen-sional You can’t simply select an area of your 3D object and hide it or paint onto it; you are lim-ited by the way the two-dimensional selection interacts with the 3D object This is apparent as you use the following tools to hide areas of your 3D object

You need to use the Selection tools to select the area of your model that you want to hide and select any one of these options from the 3D menu:

l Hide Nearest Surface: This hides the surfaces within the selection that are closest to the

view area The results are usually jagged, as you can see in Figure 24.2 You also can select this option multiple times for a cumulative effect, hiding more and more of your 3D object

l Only Hide Enclosed Polygons: This option hides all the polygons that are enclosed

within the selected area Notice in Figure 24.2 that not all of the selected area disappears, only the complete polygons within the selected area

l Invert Visible Surfaces: This option swaps the visible areas with the areas that are

hid-den, so you can make changes to the opposite areas

l Reveal All Surfaces: This brings into view any areas that are hidden

FIGURE 24.2

Hiding the nearest surface and hiding enclosed polygons protect hidden areas as well as revealing new ones

Hide nearest surface Only hide enclosed polygons

Painting on 3D objects

So are you ready to paint on your 3D object? All you need to do is grab a brush and start painting

The cello in Figure 24.3 has blank textures, so I want to liven it up by adding some color The first thing I do is open the 3D {Materials} panel and make sure the cello body is selected, as shown in Figure 24.3 Now I select a dark brown color and a hard, round brush Dragging the Brush tool over the cello adds color to it, as shown in Figure 24.4 As I drag my brush, the color is restricted

to the cello body because that is the material I have selected in the 3D panel That gives me the freedom to make big, bold strokes that completely fill the cello with paint I could have just as

3D objects created in Photoshop often tile the texture You can see this when you paint on a section; the paint

appears in several areas of the object Hiding those areas won’t stop the paint from being applied to them,

because the paint is really being applied to the image file that is being used as the object’s texture n

FIGURE 24.3

With the cello body selected in the Materials panel, it is the material affected by my painting

The brown is much better than the white, but it still doesn’t look much like the texture of the wood that would make up a cello in real life, so I choose a bristly, angled brush and create some wood grain on the surface of the cello This time, I have to be much more careful with my paint-brush, creating fairly straight, clean strokes that don’t overlap I use a darker brown color to create

a deeper wood grain over the brown of the cello The finished effect looks more like wood, as you can see in Figure 24.5

FIGURE 24.4

I can paint color onto the cello using the paintbrush in Photoshop

FIGURE 24.5

Adding a second layer of paint makes the cello look more realistic

The texture file can be opened by double-clicking the cello_body layer in the Layers panel or by selecting the Edit the Diffuse Texture button in the 3D {Materials} panel and choosing Edit Texture You can see in Figure 24.6 what the new texture looks like after my paint job Oops!

Forgot to paint the back!

FIGURE 24.6

Whoops! I missed some of the surfaces of the cello

Now I show you how to take painting a 3D object beyond color From the 3D menu, you can choose any one of seven different textures to paint on Follow these steps to see how it’s done:

1 Create a 3D shape from a layer in Photoshop

The sphere is a good shape for this exercise because the texture isn’t tiled, and the changes you make to it are not duplicated in other areas of the sphere See the sphere in Figure 24.7

2 Choose 3D ➪ 3D Paint Mode ➪ Bump

Now as you paint directly onto your object, you make changes to a bump map

FIGURE 24.7

The sphere uses the texture map only once around it, so your changes appear only in the area that you make them

Cross-Ref

To learn more about the different types of texture you can apply to your 3D object and how to edit the texture

files, see Chapter 23 n

3 Open the 3D {Materials} panel, and click the Edit the Bump Texture icon next to

the bump setting

From the drop-down menu, select New Texture, as shown in Figure 24.8

4 Choose the brush that suits your needs, and drag over your 3D object

The paint is applied to the bump map, which adds depth rather than color to your

object, as you can see in Figure 24.9

FIGURE 24.8

Create a new bump texture to paint to

FIGURE 24.9

Painting on the bump map changes the extrusion of the object

You can quickly see the merits of being able to paint directly to your object in this manner Placing your brush strokes exactly where they need to be on the texture to get the effect you want is incredibly easy You can continue to make changes to the different textures of your object in this manner, simply by choosing the texture you want to change in the 3D menu

Note

If the texture you choose to paint on (glossiness, opacity, and so on) has not already been applied to your

object, you can either create a new texture in the 3D {Materials} panel as I had you do with the bump texture,

or you can simply drag your brush over your object After you’ve tried to paint into a texture that doesn’t exist,

Photoshop creates that texture for you n

Adjustments, Layer Styles, and Filters

You also can change the look of a 3D object the same way you can change the look of any image—

using adjustments, layer styles, and filters over the entire object Especially as you use 3D objects

in composites, you’ll want to use these tools to create just the right look This isn’t as straightfor-ward as working with an image file, so I show you how it works

Note

Using adjustments, layer styles, and filters over a 3D file should not be confused with using these tools on a

texture map The texture maps attached to a 3D file are image files and can be adjusted in the time-honored

method that is always used to adjust image files in Photoshop This section focuses on applying these tools to a

3D layer n

Applying an adjustment to a 3D layer

You can apply an adjustment to a 3D layer in much the same way as you would apply it to an image file and for much the same reason Often, as you adjust the light and color of the diffuse tex-ture, you find that after it’s been applied to a 3D object, it looks much different than it did as an image It’s much darker, for one thing Applying an adjustment that changes the look of the light

or color directly to the 3D object is often the solution to getting just the look you want without having to go back and forth between the 3D file and the texture file, trying to adjust the light and color

Tip

If you are making adjustments to just your 3D object layer, be sure to clip the Adjustment layer to your 3D

object layer using the icon in the Adjustment panel This ensures that the adjustments are applied only to your

3D layer and not any other layers in your document n