Tài iệu Photoshop cs5 by Dayley part 103 pdf

Creating cross sections Creating a cross section is another very versatile option found in the scene settings within the 3D panel.. A cross section is created by cutting into a 3D object

Again you are given the opportunity to improve the quality of your rendering by sacrificing pro-cessing time This option is set by default to render your 3D object in Interactive (painting) mode

so that as you manipulate and edit your objects, you are working with them in real time rather than waiting after each move for your object to be re-rendered When you are finished creating, manipulating, and adding texture to your object, you want the final draft to be rendered in the highest quality possible At this point, choose Ray Traced Final Draft from the Quality drop-down menu This process takes several minutes at best, so be sure you are ready to complete the final rendering

Paint On

The Paint On option allows you to choose a texture to use to paint on using the 3D paint mode If you choose a texture that has not been created for your object, Photoshop creates it for you

Painting on these textures doesn’t actually leave painted pixels behind; it just makes changes to the texture When you paint on a glossy texture, for instance, you make changes to the glossiness of your 3D object

Global Ambient Color

Double-click the Global Ambient Color swatch to change the color of the reflective surfaces in your 3D scene This light doesn’t cast any direct light or shadows, but it can add a cool or warm tone to your scene

Creating cross sections

Creating a cross section is another very versatile option found in the scene settings within the 3D panel A cross section is created by cutting into a 3D object and looking into it Cross sections have several varied uses

Cross sections are great for use with architectural renderings A cross section allows you to see inside the models of 3D buildings You can see in Figure 23.9 that I cut the roof off this simple room to show you the inside of it You can see that this could be a very valuable application for looking at or editing more complex buildings or furnished rooms

You also can use cross sections to cut down any 3D model for use in a composite You can inter-sect a cross-inter-sectioned object with another object or image, or you can just use the cut down ver-sion of an object By using two instances of the same 3D model, you can open a previously solid object, such as a box, by creating matching cross sections

Select the Cross Section box in the Render Settings area of the 3D panel to get started Your 3D

FIGURE 23.9

This room had a roof before a cross section was created

FIGURE 23.10

Clicking the Cross Section box starts you out by cutting your object exactly in half

When you create a cross section, you can set the following options:

l Plane: When this box is selected, a plane is created that is a visual aid showing you

exactly how the cross section is cutting your object in two You probably want to keep the plane on while you are adjusting the settings for your cross section in order to give your-self a guide to what you are doing You can change the color or opacity of the plane

l Intersection: Click this box to outline the areas of the object that have been affected by

the cross section You can change the color of the outline by clicking the color box and making the change

l Flip: Check this box to determine which half of the object to show If I had checked this

option when I created the cross section for Figure 23.9, I would have seen the roof of the house, instead of the floor

l Offset: When you enable a cross section, your 3D object is cut exactly in half By

chang-ing the offset, you can move that dividchang-ing line to cut off more or less of your object

l Tilt: The tilt settings change the angle of the cross section By default, the angle of the cut

is parallel with the base of your object Tilt A changes the angle of the cross section front

to back, and Tilt B changes the angle side to side

l Axis: You can click any of the axis indicators to change the cross section to the indicated

axis The room in Figure 23.9 is cut along the Z-axis, while the balloon in Figure 23.10 is cut along the X-axis

Toggle the 3D extras

You can change the view of your 3D scene using the Toggle the 3D Extras icon at the bottom of the 3D panel, as seen in Figure 23.11 You can use the drop-down menu that appears when you click the icon to change the visibility of these features in your 3D workspace:

FIGURE 23.11

Toggle the visibility of these options on or off

l 3D Axis: This option toggles the visibility of the 3D Axis Widget The widget has its own

menu bar with the option to close the widget After you’ve closed it, however, the easiest way to bring it back up is to select this option

l 3D Ground Plane: In order to catch shadows and help to set perspective, a ground plane

has been placed in the 3D workspace in Photoshop You can see what it looks like when you turn it on in Figure 23.12 You can’t edit or adjust this ground plane as you would be able to do in a 3D modeling program, but you can move your 3D objects in relation to it

For instance, you can lift your objects up off of the ground plane, and the shadows falling from them reflect the idea that your object is floating

FIGURE 23.12

Turning on the visibility of the ground plane makes it easy to manipulate your object in relation to it

l 3D Light: Normally, you wouldn’t want to see the lights in your scene, but as you are

placing and adjusting them, they are so much easier to work with if you toggle their visi-bility on

l 3D Selection: This option allows you to toggle the visibility of the bounding box around

your 3D object

3D {Mesh} Panel

When you want to concentrate on making changes to the 3D object itself, select the Meshes filter icon from the 3D panel This shows the 3D {Mesh} panel, as shown in Figure 23.13 The 3D mesh

is the object itself—no textures, no lights, just the edges and vertices that make up the shape and form of the object Some objects have more than one mesh By selecting an individual mesh, you can manipulate it and edit its properties

FIGURE 23.13

The 3D {Mesh} panel

The sword shown in Figure 23.14 contains the five meshes shown in Figure 23.13 These meshes include the blade, the grip, the guard, the pommel, and the tiny button on top of the pommel You can select any one of these meshes from the 3D layers and change these settings:

l Catch Shadows: Selecting this setting allows your object to catch shadows that are cast by

other objects in your scene

l Cast Shadows: This allows your object to cast shadows In order for your object to catch

or cast shadows, at least one light must be placed in your scene

l Invisible: This option turns off the visibility of the selected mesh, but leaves the shadows

cast on the surface of the mesh behind

FIGURE 23.14

This 3D sword contains five different meshes

Note

You can rename a mesh, or any other 3D layer, by double-clicking its name n

Under the options in the settings area of the 3D panel, you see information displayed about the mesh you have selected You see the number of materials and textures applied to your mesh, as well as the number of vertices and faces that make up your mesh

You can move and manipulate individual meshes using the Mesh tool in the 3D panel You can use this tool in any of the 3D panels actually, and it doesn’t matter if you have a single mesh selected in the 3D {Mesh} panel When you select the Mesh tool, you see the options bar change to reflect the different mesh tools, as shown in Figure 23.15, just as it did when you selected the 3D object or camera tools in the Toolbox

FIGURE 23.15

The 3D Mesh tool found in the 3D panel is very similar to the 3D Object tool found in the Toolbox

To use these tools, hover over the mesh that you want to manipulate with the selected tool A bounding box appears around the mesh, as shown in Figure 23.16 Click and drag to make changes to the mesh, just as you would with the 3D Object or Camera tools

FIGURE 23.16

I can manipulate the sword’s guard by hovering over it with the Mesh Rotate tool until the bounding box

appears

Note

When the Mesh tool is selected, you can use the widget to manipulate meshes as well The widget manipulates

the mesh layer that is selected in either the 3D {Scene} panel or the 3D {Mesh} panel n

3D {Materials} Panel

You can apply several texture maps to each mesh associated with your object These texture maps control the color, texture, and highlights of your object These textures taken together constitute the material associated with a particular mesh When you have several meshes in a 3D scene, you also have several materials associated with that scene When you have the 3D {Materials} panel open, you work closely with the Layers panel to make changes to the look of your object

Figure 23.17 shows the 3D {Materials} panel along with the Layers panel associated with the wine bottle that can be created from the 3D presets You can see that three textures and three materials are associated with the bottle This is deceptive, because you might think they are the same thing, but I take you through a couple of exercises to not only demonstrate the difference between them, but show you how you can make changes to them

FIGURE 23.17

The 3D {Materials} panel lists the materials associated with your 3D object, and the Layers panel lists the

textures

Editing textures

Textures are embedded layers in your 3D object You can edit them by double-clicking the layer in the Layers panel This brings up the image file used to create the texture Make changes to the image file and save it The changes are immediately reflected on your 3D object