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19_381304-ch13.qxp Part III 7/7/08 3:03 PM Page 370 Modeling Basics You use the Smoothing Groups option to assign a subobject to a unique smoothing group. To do this, select a subobject and click a Smoothing Groups number. The Select By SG button, like the Select By ID button, opens a dialog box where you can enter a Smoothing Groups number, and all subobjects with that number are selected. The Clear All button clears all Smoothing Groups number assignments, and the Auto Smooth button automatically assigns Smoothing Groups numbers based on the angle between faces as set by the value to the right of the Auto Smooth button. The Polygon Properties rollout also includes options for setting vertex Color, Illumination, and Alpha values. Subdivision Surface Editable Poly objects include an extra rollout called Subdivision Surface that automatically smoothes the object when enabled. The Subdivision Surface rollout, shown in Figure 13.27, applies a smoothing algorithm known as NURMS, which stands for Non-Uniform Rational Mesh Smooth. It produces similar results to the MSmooth button but offers control over how aggressively the smoothing is applied; the settings can be different for the viewports and the renderer. FIGURE 13.27 The Subdivision Surface rollout includes controls for NURMS subdivision. Cage color Cage Selection color To enable NURMS subdivision, you need to enable the Use NURMS Subdivision option. The Smooth Result option places all polygons into the same smoothing group and applies the MeshSmooth to the entire object. Applying NURMS with a high Iterations value results in a very dense mesh, but the Isoline Display option displays a simplified number of edges, making the object easier to work with. The process of smoothing adds many edges to the object, and the Isoline Display option displays only the isolines. The Show Cage option makes the surrounding cage visible or invisible. The two color swatches to the right of the Show Cage option let you set the color of the cage and the selection. The Iterations value determines how aggressive the smoothing is. The higher the Iterations value, the more time it takes to compute and the more complex the resulting object. The Smoothness value determines how sharp a corner must be before adding extra faces to smooth it. A value of 0 does not smooth any corners, and a maximum value of 1.0 smoothes all polygons. 370 19_381304-ch13.qxp 7/7/08 3:03 PM Page 371 Modeling with Polygons CAUTION Each smoothing iteration quadruples the number of faces. If you raise the number of Iterations too high, the system can become unstable quickly. The two check boxes in the Render section can be used to set the values differently for the Display and Render sections. If disabled, then both the viewports and the renderer use the same settings. The smoothing algorithm can be set to ignore smoothing across Smoothing Groups and Materials. If the Show Cage option is enabled (at the bottom of the Edit Geometry rollout), an orange cage surrounds the NURMS object and shows the position of the polygon faces that exist if NURMS is disabled. This cage makes selecting the polygon faces easier. Tutorial: Modeling a tooth If you’ve ever had a root canal, then you know how much pain dental work can cause. Luckily, modeling a tooth isn’t painful at all, as you’ll see in this example. To model a tooth using NURMS, follow these steps: 1. Select Create ➪ Standard Primitives ➪ Box, and drag in the Top viewport to create a Box object. Set its dimensions to 140 × 180 × 110 with Segments of 1 × 1 × 1. Then right-click, and select Convert To ➪ Editable Poly from the pop-up quadmenu. 2. Click the Polygon icon in the Selection rollout to enable Polygon subobject mode. Then select the Top viewport, and press B to change it to the Bottom viewport. Then click the box’s bottom polygon in the Bottom viewport. 3. Click the Select and Scale button (R), and scale the bottom polygon 10%. 4. Drag over the entire object to select all polygons, and click the Tessellate button in the Edit Geometry rollout once to divide the polygon into more polygons. Then select Edit ➪ Region ➪ Window (or click the Window/Crossing button in the main toolbar) to enable the Window selection method, and drag over the bottom of the Box object in the Left viewport to select just the bottom polygons. Click the Tessellate button again. 5. Select the Vertex subobject mode in the Selection rollout, press and hold the Ctrl key, and select the vertices at the center of each quadrant. Then move these vertices downward in the Left viewport a distance about equal to the height of the Box. 6. Select the Bottom viewport again, and press T to change it back to the Top viewport. Select the single vertex in the center of the polygon with the Ignore Backfacing option enabled in the Selection rollout, and drag it slightly downward in the Left viewport. 7. Disable the Ignore Backfacing option in the Selection rollout, and select the entire second row of vertices in the Left viewport. With the Select and Scale tool, scale these vertices toward the center in the polygon in the Top viewport. 8. In the Subdivision Surface rollout, enable the Use NURMS Subdivision option and set the Iterations value to 2. Figure 13.28 shows the completed tooth. 371 13 19_381304-ch13.qxp Part III 7/7/08 3:03 PM Page 372 Modeling Basics FIGURE 13.28 The organic look for this tooth is accomplished with NURMS. Summary Meshes are probably the most common 3D modeling types. You can create them by converting objects to Editable Meshes or Editable Poly objects or by collapsing the Stack. Editable Poly objects in Max have a host of features for editing meshes, as you learned in this chapter. More specifically, this chapter covered the following topics:




Creating Editable Poly objects by converting other objects or applying the Edit Poly modifier The features for editing Editable Poly objects How to select and use the various mesh subobject modes Editing mesh objects using the various features found in the Edit Geometry rollout Changing surface properties using features like NURMS This chapter concludes Part III, “Modeling Basics.” You’re now ready to learn about dressing up objects with materials, cameras, and lights. The next chapter covers the basics of applying materials. 372 20_381304-pp04.qxp 7/7/08 2:54 PM Page 373 Materials, Cameras, and Lighting Basics IN THIS PART Chapter 14 Exploring the Material Editor Chapter 15 Creating and Applying Standard Materials Chapter 16 Creating Compound Materials and Using Material Modifiers Chapter 17 Adding Material Details with Maps Chapter 18 Configuring and Aiming Cameras Chapter 19 Using Lights and Basic Lighting Techniques 20_381304-pp04.qxp 7/7/08 2:55 PM Page 374 21_381304-ch14.qxp 7/7/08 2:38 PM Page 375 Exploring the Material Editor M aterials are used to dress, color, and paint objects. Just as materials in real life can be described as scaly, soft, smooth, opaque, or blue, materials applied to 3D objects can mimic properties such as color, texture, transparency, shininess, and so on. In this chapter, you learn the basics of working with materials and all the features of the Material Editor. IN THIS CHAPTER Understanding Material properties Working with the Material Editor Understanding Material Properties Before jumping into the Material Editor, let’s take a close look at the type of material properties that you will deal with. Understanding these properties will help you as you begin to create new materials. Up until now, the only material property that has been applied to an object has been the default object color, randomly assigned by Max. The Material Editor can add a whole new level of realism using materials that simulate many different types of physical properties. NOTE Many of these material properties are not visible until the scene is rendered. Colors Color is probably the simplest material property and the easiest to identify. However, unlike the object color defined in the Create and Modify panels, there isn’t a single color swatch that controls an object’s color. Consider a basket of shiny red apples. When you shine a bright blue spotlight on them, all the apples turn purple because the blue highlights from the light mix with the red of the apple’s surface. So, even if the apples are assigned a red material, the final color in the image might be very different because the light makes the color change. 375 Using the Material/Map Browser Working with libraries of materials Using the Material/Map Navigator 21_381304-ch14.qxp Part IV 7/7/08 2:38 PM Page 376 Materials, Cameras, and Lighting Basics Within the Material Editor are several different color swatches that control different aspects of the object’s color. The following list describes the types of color swatches that are available for various materials:
Ambient: Defines an overall background lighting that affects all objects in the scene, including the color of the object when it is in the shadows. This color is locked to the Diffuse color by default so that they are changed together.
Diffuse: The surface color of the object in normal, full, white light. The normal color of an object is typically defined by its Diffuse color.
Specular: The color of the highlights where the light is focused on the surface of a shiny material.
Self-Illumination: The color that the object glows from within. This color takes over any shadows on the object.
Filter: The transmitted color caused by light shining through a transparent object.
Reflect: The color reflected by a raytrace material to other objects in the scene.
Luminosity: Causes an object to glow with the defined color. It is similar to Self-Illumination color but can be independent of the Diffuse color. NOTE Standard materials don’t have Reflectivity and Luminosity color swatches, but these swatches are part of the Raytrace material. If you ask someone the color of an object, he or she would respond by identifying the Diffuse color, but all these properties play an important part in bringing a sense of realism to the material. Try applying very different, bright materials to each of these color swatches and notice the results. This gives a sense of the contribution of each color. For realistic materials, your choice of colors depends greatly on the scene lights. Indoor lights have a result different from an outdoor light like the sun. You can simulate objects in direct sunlight by giving their Specular color a yellow tint and their Ambient color a complementary, dark, almost black or purple color. For indoor objects, make the Specular color bright white and use an Ambient color that is the same as the Diffuse color, only much darker. Another option is to change the light colors instead of changing the specular colors. TIP Opacity and transparency Opaque objects are objects that you cannot see through, such as rocks and trees. Transparent objects, on the other hand, are objects that you can see through, such as glass and clear plastic. Max’s materials include several controls for adjusting these properties, including Opacity and several Transparency controls. Opacity is the amount that an object refuses to allow light to pass through it. It is the opposite of transparency and is typically measured as a percentage. An object with 0 percent opacity is completely transparent, and an object with 100 percent opacity doesn’t let any light through. Transparency is the amount of light that is allowed to pass through an object. Because this is the opposite of opacity, transparency can be defined by the opacity value. Several options enable you to control transparency, including Falloff, Amount, and Type. These options are discussed later in this chapter. Reflection and refraction A reflection is what you see when you look in the mirror. Shiny objects reflect their surroundings. By defining a material’s reflection values, you can control how much it reflects its surroundings. A mirror, for example, reflects everything, but a rock won’t reflect at all. 376 21_381304-ch14.qxp 7/7/08 2:38 PM Page 377 Exploring the Material Editor Reflection Dimming controls how much of the original reflection is lost as the surroundings are reflected within the scene. Refraction is the bending of light as it moves through a transparent material. The amount of refraction that a material produces is expressed as a value called the Index of Refraction. The Index of Refraction is the amount that light bends as it goes through a transparent object. For example, a diamond bends light more than a glass of water, so it has a higher Index of Refraction value. The default Index of Refraction value is 1.0 for objects that don’t bend light at all. Water has a value of 1.3, glass a value of around 1.5, and solid crystal a value of around 2.0. Shininess and specular highlights Shiny objects, such as polished metal or clean windows, include highlights where the lights reflect off their surfaces. These highlights are called specular highlights and are determined by the Specular settings. These settings include Specular Level, Glossiness, and Soften values. The Specular Level is a setting for the intensity of the highlight. The Glossiness determines the size of the highlight: Higher Glossiness values result in a smaller highlight. The Soften value thins the highlight by lowering its intensity and increasing its size. A rough material has the opposite properties of a shiny material and almost no highlights. The Roughness property sets how quickly the Diffuse color blends with the Ambient color. Cloth and fabric materials have a high Roughness value; plastic and metal Roughness values are low. Specularity is one of the most important properties that we sense to determine what kind of material the object is made from. For example, metallic objects have a specular color that is the same as their diffuse color. If the colors are different, then the objects look like plastic instead of metal. NOTE Other properties Max uses several miscellaneous properties to help define standard materials, including Diffuse Level and Metalness. The Diffuse Level property controls the brightness of the Diffuse color. Decreasing this value darkens the material without affecting the specular highlights. The Metalness property controls the metallic look of the material. Some properties are available only for certain material types. Before proceeding, you need to understand the difference between a material and a map. A material is an effect that permeates the 3D object, but most maps are 2D images (although procedural 3D maps also exist) that can be wrapped on top of the object. Materials can contain maps, and maps can be made up of several materials. In the Material Editor, materials appear shaded in the sample slots, and maps appear as 2D images. Usually, you can tell whether you’re working with a material or a map by looking at the default name. Maps show up in the name drop-down list as Map and a number (Map #1), and materials are named a number and Default (7- Default). NOTE Working with the Material Editor The Material Editor is the interface with which you define, create, and apply materials. You can access the Material Editor by choosing Rendering ➪ Material Editor, clicking the Material Editor button on the main toolbar (it has four small rendered spheres on the icon), or using the M keyboard shortcut. 377 14 21_381304-ch14.qxp Part IV 7/7/08 2:38 PM Page 378 Materials, Cameras, and Lighting Basics Using the Material Editor controls At the top of the default Material Editor window is a menu of options including Material, Navigation, Options, and Utilities. The menu commands found in these menus offer the same functionality as the toolbar buttons, but the menus are often easier to find than the buttons with which you are unfamiliar. Below the menus are six sample slots that display a preview of some available materials. Surrounding these slots are button icons for controlling the appearance of these sample slots and interacting with materials. Figure 14.1 shows the Material Editor. The button icons to the right and below the sample slots control how the materials appear in the editor. These buttons are defined in Tables 14.1 and 14.2. FIGURE 14.1 Use the Material Editor window to create, store, and work with materials. Sample slots Vertical buttons Horizontal buttons Material names 378 21_381304-ch14.qxp 7/7/08 2:38 PM Page 379 Exploring the Material Editor TABLE 14.1 Material Editor Buttons — Vertical Toolbar Button Name Description Sample Type (Sphere, Controls the type of object displayed in the sample slot. The default object is a sphere. Other options available as flyouts include a cylinder and a cube. You can also select a custom object to use as the preview object. Cylinder, Box, Custom) Backlight (L) Turns backlighting in the selected sample slot on or off. Background (B) Displays a checkered background image (or a custom background) behind the material, which is helpful when displaying a transparent material. Sample UV Tiling (1×1, Sets UV tiling for the map in the sample slot. The default is 1 × 1. Additional options available as flyouts are 2 × 2, 3 × 3, and 4 × 4. This setting affects only maps. 2 × 2, 3 × 3, 4 × 4) Video Color Check Checks the current material for colors that are unsupported by the NTSC and PAL formats. Make Preview (P), Used to generate, view, and save material preview renderings. These animated material previews enable you to see the effect of an animated material before rendering. Play Preview, Save Preview Options (O) Opens the Material Editor Options dialog box. This dialog box includes settings for enabling material animation, loading a custom background, defining the light intensity and color, and specifying the number of sample slots. Select by Material Selects all objects using the current material. This button opens the Select Objects dialog box with those objects selected. Material/ Map Navigator Opens the Material/Map Navigator dialog box. This dialog box displays a tree of all the levels for the current material. 379 14