Wiley Maya Studio Projects Texturing and Lighting
Contents
1. Figure 1 32 When painting the bump map texture it may be difficult to determine where the groove should be positioned in relation to the UV snapshot To make this process easier you can follow these steps 1 Ina Maya view panel RMB click the Junction_L or Junction_R surface and choose Face from the marking menu Proceed to Shift click the faces that would make a suitable location for the groove 2 Open the UV Texture Editor The selected faces will be isolated Make a note of the face locations within the UV texture space If need be you can switch back and forth between Maya and Photoshop while painting the texture 3 Even though the anti aliasing quality has been set to high you may notice that small details appear soft In part this is because of the automatic activation of the Use Multi Pixel Filter attribute Multi pixel filtering averages the pixels within a render as a post process This helps prevent anti aliasing issues such as stair stepping Unless the ren der is destined for video output however the filtering can make the render excessively blurry You can turn off the filtering by deselecting the Use Multi Pixel Filter check box in the Maya Software tab of the Render Settings window Other parts of the headphones model can benefit from custom bitmaps mapped to Color attributes For example the plastic ear cups are a suitable location for a large logo see Figure 1 33 To create such a bitmap you can follow2. The result of similar lighting on a face Bottom Right The result of similar lighting on a product in this case a restaurant meal Because the goal of this project is to light the head phones aesthetically we can copy lighting approaches applied by glamour photography and music video videography One common technique of such media requires the addition of a strong diffuse key light or lights placed beside or close to the camera A single light might take the form of a fluorescent ring that circles the camera Alternatively two equally intense lights might be placed on either side of the camera and softened by translucent soft boxes or diffusion material see Figure 1 13 Such lights may also be bounced off reflective cards or purpose built reflec tive umbrellas By aligning the lights with the cam era visible shadows are minimized For a human this results in the reduction of noticeable wrinkles and similar flaws For a product this ensures that the parts of the product are clearly seen that is no part is made obscure by darkness On a psychological level a brightly lit subject with few shadows often produces a positive reaction Conversely a poorly lit subject with deep dark shadows is associated with gloomy or dis turbing subject matter such as film noir or horror When a light is referred to as diffuse its light rays diverge and overlap in such a way as to produce LIGHTING TECHNIQUES AND Maya LIGHT TYPES soft
3. attribute to 0 5 Last fine tune the Color and Diffuse attributes of the material assigned to Foam surfaces Figure 1 26 for example has Color set to dark gray 0 19 0 19 0 19 in RGB and Diffuse set to 0 36 Creating Custom Bitmaps Although procedural textures are suitable for creating semirandom patterns they cannot re create specific designs or features Hence the addition of printed logos for the head phones requires the creation of custom bitmaps To create a custom bitmap it will be necessary to export the UV texture space of a targeted surface from Maya and bring it into a digital paint program For example to cre ate a bitmap texture for a headphone junction the plastic part between the chrome slider and the head pad you can use Adobe Photoshop with the following steps 1 In Maya select the Junction_R geometry as a surface and choose Window gt UV Tex ture Editor From the editor s menu choose Polygons gt UV Snapshot The UV Snap shot window opens allowing you to export the UV texture space as a bitmap see Figure 1 27 Use the File Name browse button to choose a file name and directory location Change the Size X and Size Y attribute values to an appropriate resolution PROJECT APPLYING TEXTURES 25 In this case it s best to choose a resolution that will match the desired resolution of the final texture For example 1024x1024 is appropriate for a small piece of geom etry when rendering at HD 720 Chang
4. edged shadows A focused light on the other hand creates parallel rays of light that create hard edged shadows Diffuse lights are often referred to as soft Focused lights are often referred to as hard Adding Lights to a Scene When adding lights in Maya it s generally best to create one at a time That is each light should be satisfactorily positioned and adjusted before additional lights are created As such it pays to follow the lighting conventions used for cinematic and photographic light ing Each light is assigned a specific task that ultimately determines its position and inten sity The tasks are generally broken down into the following Key A key light is the most intense light in the scene The key light s source is generally identifiable the sun a lamp and so on The key light usually produces the strongest shadow in the scene If two light sources are equally intense as is the case with the glam our photography in Figure 1 13 they both may be considered key lights Fill A fill light is a secondary light that is less intense than the key This light fills in the dark areas of a subject and the shadows produced by the key Fill lights often represent light from a key that has bounced off a surface such as a wall Rim A rim light is an intense light source that arrives from the back of a subject so that it strikes the subject along the edge Rim lights when used in photography and cinematog raphy are al
5. steps similar to those listed at the beginning of this section The headphone ear pads can also benefit from a custom bump texture The Pad_L and Pad_R sur faces utilize the full UV texture space with a single UV shell for each surface Because each polygonal surface is doughnut shaped there is a seam where the left and right sides of the UV texture space meet in 3D space You can locate this seam by RMB clicking in the UV Texture Editor choosing Face from the marking menu and Shift clicking all the faces that form a vertical column on the far left or far right side The corresponding faces are highlighted in the view panels see Figure 1 34 Real world headphone ear pads are often bunched leather that creates numerous parallel grooves Because the UV shell for the pad geometry is square such bunches must be painted as vertical black gray and white streaks as shown in Figure 1 35 When it comes to bump maps 50 percent gray leaves the surface unaffected while high values create ridges and low values create grooves You can create such streaks in Photoshop by manually using the Brush tool or cutting and pasting from a photo that contains similar vertical features As a bonus you can add horizontal white dashes to replicate stitching that occurs near the pad edge For example Figure 1 35 illustrates a completed texture Note that a texture need not be perfectly square to function In fact with the pad geometry it s easier to fit i
6. the Diffuse attribute smooth silhouette edge of the presence of myriad surface imperfections that scatter light in a random fashion controls the degree to which light rays are reflected in all directions A high Diffuse 6 The Specular Shad CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Figure 1 7 ing section of a Blinn material value produces a bright surface A low Diffuse value causes light rays to be absorbed and thereby makes the surface dark Translucence Translucence Depth Translucence Focus The Translucence attribute in conjunc tion with Translucence Depth and Translucence Focus simulates the diffuse penetration of light into a solid surface In the real world you can see the effect when holding a flashlight to the palm of your hand Translucence naturally occurs with hair wax fur paper leaves and human flesh The Translucence attribute is discussed further in Chapter 4 Texturing and Lighting a Character Part 2 Adding Specularity The Lambert material does not possess specularity Specularity is the consistent reflection of light in one direction that creates a hot spot on a surface In CG programs specularity is emulated by creating a specular highlight In Maya specular highlights are controlled specular Shading through a material s Specular Shading section see Figure 1 7 Specular Roll OF 0 700 ppecular Color The Specular Shading section is carried by Reflectwty 0
7. the Status Line include the A Select By Hierarchy And Combinations button B Select By Object Type button C Select By Component Type button and D object type component type option buttons Plastc_Junction Figure 1 11 A shading network revealed in the Hypershade work area Generally it s best to match the Maya material type to the real world material the surface is emulating For example if a material needs a specular highlight a Lambert material 10 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Table 1 1 Recommended material types is inappropriate and a Blinn is suitable As such Table 1 1 lists each of the surfaces found in the headphones scene file the real world material it will try to emulate and the recom mended Maya material type SURFACE NAME REAL WORLD MATERIAL RECOMMENDED MAYA MATERIAL Slider Chromed metal Phong Junction Black plastic Blinn Wire Black rubber Blinn Foam Gray cell foam Lambert Ear_Cup Black plastic Blinn Ear_Pad Thin bunched white leather Blinn Grommet Semitransparent yellow plastic Blinn Head_Pad Plastic stamped to simulate leather Blinn Light_Box wall Translucent white fabric Surface Shader You can take one of two approaches to determine the total number of materials needed for a scene e Create a new material for each surface For example assign the Foam_L surface to a Foam_L_Color material and assign the Foam_R surface to a Foam_R_Color material This all
8. the camera s view For example when you render with Maya Software in the Render View window the bottom center section of the view is the first to appear In contrast the raytracing process fires off a virtual ray from the camera eye through each pixel of the view plane Essentially the view plane is a 2D grid that s perpendicular to the axis of the camera lens that is the grid is coplanar to the virtual film back The grid pos sesses the same dimensions as the pixel size of the chosen render resolution The first surface a ray hits determines the pixel color That is the material qualities of the surface are used in the shading calculation of the pixel If the surface is reflective or refractive additional rays are created at the surface intersection point One ray represents the reflection and one ray represents the refraction These rays continue until they intersect another surface Additional reflection and or refraction rays are born at the new intersection point if the associated mate rial is reflective or refractive To prevent an infinite number of rays from being born limits are placed on the total number of permitted rays Refraction differs from reflection in that a refractive ray travels through a surface Real world refractive materials such as glass or water are perceived as transparent or semitransparent With Maya Software raytracing is activated via the Raytracing check box found within the Raytracing Quality section
9. the material assigned to the Junction_R surface and open its Attribute Editor tab Click the Color checkered Map button In the Create Render Node window click the File texture icon File and 2d Placement nodes are added to the shading network Open the new File node s Attribute Editor tab Click the Image Name attribute s Browse button and retrieve the texture you wrote out from Photoshop If the Junction_L surface is assigned to a separate material repeat this process with that material Render a test The screw heads and logo should appear in the correct loca tions see Figure 1 31 It s important to remember that Maya does not store bitmap textures in its scene file That is when you save an mb or ma Maya scene file the bitmap textures are left in their original location and in their original state the file simply records the location of the texture as a line of text Therefore it s best to save the textures in a logical and accessible location For exam ple if the scene files are saved to C ProjectFiles Project1 save the bitmap textures to C ProjectFiles Project1 Textures If you open a scene file and discover that a File texture is missing or otherwise renders black you will need to reload it To do so open the File texture node s Attribute Editor tab and click the Reload button below the Image Name attribute If Reload fails use the Image Name Browse button to relocate the texture file Figure 1 31 When op
10. the printed logo uses metallic flake paint you can use masking tools to cut a noisy layer into a text like shape see Figure 1 30 To do so create a new layer and add white text Again you can use the Type tool or cut and paste from a bitmap that already carries text Create a new layer and paint a pattern that emulates gold flake paint If this is too difficult to paint cut and paste from a photo that has a similar noisy pattern for example glitter or sand If the photo s colors are incorrect choose Image gt Adjustments gt Color Balance and fine tune the red green and blue mixture After the gold flake paint layer is completed switch back to the text layer by clicking on the corresponding layer name in the Layers panel Using the Magic Wand tool click within the white area of one letter Choose Select gt Similar This selects all the white text Choose Select gt Inverse Return to the gold flake paint layer Choose Edit gt Cut The gold flake paint is cut out in the shape of the text PROJECT APPLYING TEXTURES 27 eh tapes y He i ba ag m he A gt OF jE PE a he ypa Oe s ata a hoa kx 6 When you ve finished painting the various layers choose Layer gt Flatten Image Choose File Save and select a Maya compatible file format Targa or TIFF are both high quality formats When choosing a filename strive for clarity For example name the file Junc tion_Color Return to Maya Open the Hypershade select
11. 500 ee ee Reflected Color Phong Phong E Blinn and Anisotropic materi als All four materials share the following specu lar highlight attributes Specular Color Specular Color sets the color of the specular highlight Reflectivity Reflectivity controls the intensity of raytraced reflections and reflections simulated with the Reflected Color attribute By default the Maya Software renderer does not raytrace For an introduction to raytracing see the Project Raytracing Reflections section later in this chapter Reflected Color If the Reflected Color attribute is set to any color other than black or is mapped a simulated reflection is applied directly to the assigned surface Reflected Color does not require raytracing to function The Reflected Color attribute is demonstrated in Chapter 5 Texturing and Lighting a Vehicle Part 1 Whereas the Blinn material controls the specular highlight size with the Eccentricity attribute Phong uses the Cosine Power attribute and Phong E uses the Roughness and Highlight Size attributes The Anisotropic material controls the size shape and rotation of its specular highlight with the Angle Spread X Spread Y and Roughness attributes The Anisotropic highlight can assume circular vertical or horizontal patterns see Figure 1 8 Technically speaking an anisotropic surface is one that reflects light unevenly in such a case the unevenness is dependent on direction Real worl
12. CHAPTER 1 Texturing and Lighting a Product Part 1 I n this chapter and Chapter 2 Texturing and Lighting a Product Part 2 you will texture and light a pair of headphones This chapter which contains part 1 of the project will guide you through the following steps Reviewing the scene file Assigning materials Creating lights and shadows Applying textures Raytracing reflections In addition important lighting and texturing theory is included as follows Material types and critical attributes Hypershade functionality Lighting techniques and Maya light types Procedural textures Scanline and raytraced rendering Although many tutorials would treat a pair of headphones as a traditional still life this project approaches the scene as if selling a product In the realm of business a prod uct is a good or service that fulfills the need of a particular market A product is often a physical object a seller offers a potential buyer Hence the goal of texturing and light ing a product is to present it aesthetically so that a buyer might desire it This requires a unique approach to texturing and lighting 2 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 5 Figure 1 1 Left Hypergraph view of the head phones hierarchy Right Outliner view of the same hierarchy Group nodes are indicated by the white trap ezoid symbols Project Reviewing the Scene File Before starting the texturing process revi
13. Z depth buffer With a Z depth buffer the distance from 2D AND 3D PROCEDURAL TEXTURES 19 the light is encoded in various shades of gray surfaces close to the light receive higher val ues and surfaces far from the light receive lower values If there is only one light in a scene the shadow renders black You can add a fill light to brighten the shadow However the fill light will also brighten the unshadowed area of the surface An alternative solution is to adjust the light s Shadow Color attribute For example in Figure 1 20 Shadow Color is set to a light blue In this case Filter Size is set to 32 2D and 3D Procedural Textures Maya provides a number of textures that are procedural A procedural texture is one that is mathematically generated through a predefined algorithm Procedural textures are reso lution independent and do not have defined edges or borders The textures fall into two categories 2D and 3D 2D procedural textures create a pattern in two dimensions U left right and V down up These textures include Bulge Checker Cloth Fractal Grid Mountain Noise Ramp and Water When you map a 2D texture to the attribute of a material two nodes are cre ated and connected to the material node The first node is the texture node which car ries the attributes that determine the quality of the texture Because several procedural textures are based on fractal noise patterns a number of attributes are shared The s
14. adiates from the light icon and is identical to a point light Ambient lights are suitable as fill and are usually inappropriate as a key Volume The volume light acts as a point light but is contained within the volume of the light s icon You can scale the icon to any size By default the icon is spherical but you can change it to a cylinder or cone through the light s Light Shape attribute By default the light s intensity tapers from the icon center to the icon edge The rapidity of this taper is controlled by the Color Range and Penumbra gradients For a surface to be lit by a volume light it must rest within the interior of the light icon For a demonstration of the volume light s unusual functionality see Chapter 2 15 16 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Figure 1 16 Scaled and posi tioned area light that will serve as the key as seen from the Top and Front view panels Project Creating Lights and Shadows After you ve adjusted the material Color and Transparency attributes you can begin light ing Although Maya provides a default light when no light nodes are present the light quality is not driven by any particular light source Hence the default light is not suitable for judging assigned materials or added textures Setting the Key Light Although you have a fairly wide selection of light types in Maya we will use an area light to serve as the key for the headphones scene The soft
15. at relates pixels of a texture map to positions on a sur face UV points represent the location of a polygon s vertices within a UV texture space If polygon faces overlap within the UV texture space they share the same section of an assigned texture Hence the majority of sur faces in the headphones scene possess a UV layout that avoids over lapping faces The few faces that are allowed to overlap are for small unseen parts of the model For an example of such overlapping see the section Creating Custom Bitmaps later in this chapter Working with Multiple Cameras The headphones scene file contains two perspective cameras persp and Render By default the persp camera is included in every Maya scene file You can use the persp camera to exam ine different parts of the model The Render camera on the other hand is positioned and animated for the final render and should not be moved To switch between persp and Render in any view panel choose Panels gt Perspective gt camera name from the view panel menu Note that the Render camera has the Resolution Gate option activated The Resolution Gate appears in the view panel workspace as a green box with a grayed out outer area see PROJECT REVIEWING THE SCENE FILE 3 Figure 1 3 The box indicates the outer edge of the render surfaces outside the box will not render To toggle the Resolution Gate on or off for any camera choose View gt Camera Settings gt Resolution Gate f
16. attributes will require adjustment after Specular Roll Off is switched from a solid color to a mapped file In addition to adjusting the Eccentricity and Specular Color to affect the size and intensity of a highlight you can lighten or darken the generic specularity texture within Maya To darken the texture lower the texture node s Color Gain attribute value To lighten the texture raise the texture node s Color Offset value Color Gain and Color Offset are located in the texture node s Color Balance section If you raise the Color Offset while lowering the Color Gain you reduce the contrast found within the texture SCANLINE AND RAYTRACED RENDERING 31 To create a generic noise pattern you can combine photos of real world surfaces Rusty metal stucco dirty concrete and similar surfaces often contain interesting patterns In fact if you layer several different photos in Photoshop and adjust each layer s Opacity you can generate a more complex result For example if you stack three different rusty metal photos and reduce each layer s Opacity an interesting pattern forms see Figure 1 37 To convert the result to grayscale choose Layer gt Flatten Image and Image gt Adjustments gt Desaturate To adjust the overall contrast apply Image gt Adjustments gt Brightness Contrast or Image gt Adjustments gt Curves TE Scanline and Raytraced Rendering By default the Maya Software renderer operates
17. cialized Maya materials Surface Shader Use Background and Layered Shader are perhaps the most useful Descriptions of each follow Surface Shader The Surface Shader material is a pass through node It carries no shad ing properties and does not take into account any lights or shadows A surface assigned to a Surface Shader material will appear self illuminated Hence the material is appropriate for any surface that needs to retain a maximum intensity regardless of the scene s light ing For example a half sphere assigned to a Surface Shader with a sky photo mapped to its Color attribute does not need to be lit As a working example a Surface Shader mate rial will be assigned to the Light_Box geometry later in this chapter Use Background The Use Background material picks up the color of the camera s Background Color attribute which is black by default or an image plane attached to the camera If you assign Use Background to surfaces that are receiving shadows the shadows are trapped in Left Nonspherical highlight of Anisotro pic material Middle Anisotropic high light on human hair Right Anisotropic reflection on choppy water 8 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 an alpha channel and the RGB channels remain black This offers a handy means to render shadows as a separate render pass For a demonstration of the Use Background material and render passes see Chapter 6 Texturing and Lighti
18. d anisotropic surfaces possess parallel channels grooves fibers or tube like structures Human hair brushed metal and choppy water therefore fit the anisotropic category If a surface creates specular highlights that are elongated and perpendicular to the channels grooves fibers tubes it is anisotropic MATERIAL TYPES AND CRITICAL ATTRIBUTES 7 Keep in mind that 3D specular highlights are an artificial construct Real world specular highlights are actually reflections of intense light sources such as a day sky or a bright lamp The intensity of the Maya specular highlight is controlled by the Specular Roll Off Blinn Whiteness Phong E and Fresnel Index Anisotropic With the Phong material you can adjust the specular intensity by changing the Specular Color anisotropic Using Specialized Materials In addition to Lambert Blinn Phong Phong E and Anisotropic Maya offers several spe cialized materials These are available in the Maya section of the Hypershade Create tab In addition a large number of mental ray materials are included in the mental ray sec tion Although the mental ray renderer can render either Maya or mental ray materials the Maya Software renderer can render only Maya materials Nevertheless while textur ing and lighting the headphones we ll work solely with Maya materials Information on mental ray materials is included in Chapter 7 Texturing and Lighting an Environment Part 1 Of the spe
19. e the Image Format menu to a format that s supported by a digital paint program such as Photoshop For example JPEG is a commonly used format that produces sufficient quality for the texture painting process If you choose an image format that supports alpha such as Targa or TIFF the UV information will be written to an alpha channel Click the OK button The UV texture space is written out with the name and location defined by the File Name attribute be irememes sec Launch Photoshop Open the UV snapshot file you just Y UV Snapshot File name Zoouments maya projects default images ui wrote out The UV texture space appears with the UV shells laid out in white over a black background see Ee Keep aspectratio Figure 1 28 By default only the 0 to 1 0 UV space is Coior vake M s Ant alas ines included U runs left to right and V runs down to up a UY Range Options with 0 0 at the bottom left corner If UV shells or r UV points fall outside the 0 to 1 0 area they receive a OK repeated part of the texture Note that the tubes run Figure 1 27 ning through the center of the Junction_R surface The UV Snapshot window overlap the surface sides Overlapping faces share the same part of any assigned texture For this h Junction R_Uvstga 50 RGB B XH p Be B 3 reason you usually want to avoid such overlap However in this situation the overlap is unim portant because the walls of the tubes a
20. econd added node is a 2d Placement utility node see Figure 1 21 This node controls the UV tiling of the texture If the node s Repeat UV attribute is set to 1 1 the texture appears one Figure 1 19 Left Detail of depth map shadow with default 512 Resolu tion Right Improved shadow with 2048 Resolution Asample file is saved as headphones step4 maon the DVD 20 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 time across the surface in the U and V directions Additionally the 2d Placement utility node offers attributes to offset mirror or rotate the procedural pattern Figure 1 20 Filter Size is set to 32 and Shadow Color is set toa light blue A sample file is saved as headphones step5 maon the DVD Y 2d Texture Placement Attributes Interactive Placement Coverage 1 000 1 000 Translate Frame 0 000 00g Rotate Frame 0 010 m Mirror U v irap U Stagger Repeat UV 1 000 Offeet 6 000 Rotate LV 0 000 Ainge UY 0 000 Fast Figure 1 21 Top A 2d Placement utility node auto matically named place2dTexture1 con nected to a Noise texture node Bottom The utility s UV tiling attributes Note that two naming conventions are applied to any given node in Maya a nice name and a long name A nice name includes spaces and features capitalization A long name carries no spaces and sometimes features a different word order For example 2d Placement is a nice name whi
21. ening Chapter 1 sample scene files you can avoid missing bitmap textures by first choosing File gt Project gt Set the color insert Figure 1 30 Left White text over black Middle Bitmap photo of gold glitter Right Photo cut out in the shape of the letters with the appli cation of the Magic Wand selection and cut tools A finished texture is included as Junction_Color tga in the ProjectFi les Projectl1 Textures folder on the DVD Custom bitmap texture applied to Junction material as seen on frame 36 For a color version of the figure see 28 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Figure 1 32 Left Custom bump texture Right Junc tion rendered with a bumped groove along the side A sample file is saved as headphones step9 ma A finished texture is included as Junction_Bump tgain the Project Files Project1 Textures folder on the DVD and browsing for the Project1 folder whether the folder remains at its original location on the DVD or is located on a drive after the DVD contents have been copied When creating custom bitmaps you re not limited to color For example you can cre ate the illusion that the plastic junction is composed of two halves with a central groove by painting a new texture and mapping it to the Bump Mapping attribute of the associ ated material The groove requires a black line on the texture while the unaffected areas are filled with 50 percent gray see
22. er animator mS e Light _ Box Fabric Plastic Ear Cup Pane Plastic Junction if the materials are named clearly the Figure 1 12 animator will have no problem navigat Oe Materials created for the headphones scene Each material is assigned to surfaces that share the same look For example the Wire material is assigned the materials are assigned For example to the Wire_L Wire_R and Cord surfaces Note that the material names are easy to interpret A sample Maya file is saved as headphones step1 ma inthe ProjectFiles Project1 folder on the DVD For a color version of the figure headphones scene file see the color insert ing the Hypershade and determining how Figure 1 12 shows materials created for the Adjusting Colors and Transparency After you ve assigned materials to all the surfaces in the scene adjust the Color attribute for each material Match the colors listed in Table 1 1 earlier in this chapter as well as those illustrated in Figure 1 12 To access the Color Chooser click the Color attribute s color swatch With the Color Chooser you can select a color by LMB dragging the color wheel handles or the R G B red green blue sliders You can also enter values into the R G B number cells By default the color scale runs from 0 to 1 0 for each color channel You can switch from the RGB color model to an HSV hue saturation value one by changing the lower right menu After you move your mouse off the Color Choose
23. ew the scene file and its contents Open the headphones start ma scene file from the ProjectFiles Project1 folder on the DVD The scene hierarchy surface UV texture space camera setup and unique light box geometry should all be examined before proceeding further Checking the Hierarchy and UVs The headphones model is constructed from 16 polygon surfaces The surface nodes are grouped together as a single hierarchy see Figure 1 1 You can view the hierarchy through the Hypergraph Window gt Hypergraph Hierarchy or the Outliner Window gt Outliner You can select group or surface nodes through the Hypergraph and the Outliner Technically speaking a node is a construct that holds specific information and any actions associated with that information In Maya a node may be a surface a light a camera a material and so on All the polygon surfaces carry a completed UV texture space That is each surface s UV points are arranged in such a fashion that the texturing may begin immediately The UV points are laid out as a single shell or as multiple shells surrounded by empty UV texture space see Figure 1 2 You can examine the UV texture space of a surface by selecting the surface and choosing Window gt UV Texture Editor Approaches for examining and utilizing the UV points and shells are discussed in the section Creating Custom Bitmaps later in this chapter Technically speaking UV texture space refers to a coordi nate system th
24. in a scanline mode The scanline process operates with these basic steps Surfaces visible to the rendering camera are noted Occlusion of one surface by another is taken into account Polygon faces of the visible surfaces are projected into 2D screen space The faces are processed in scanline order A scanline is a row of pixels within a render Technically speaking a pixel is a sample point that carries an x y coordinate and a color value for an image to be stored in a digital system it must be broken down into a discrete number of pixels Hence a 1280x720 render has 720 scanlines with each scanline possessing 1280 pixels Figure 1 37 Three photo bit maps of rusty metal are placed on three different layers in Photoshop The top and middle layers are given reduced Opacity values lead ing to a more com plex result after the layers are flattened and desaturated 32 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Y Raytracing Quality Reflections 2 Refachons 0 Shadows 2 Dias Figure 1 38 The final color of each pixel within a scanline is based on the material qualities of the polygon face found within the pixel In addition the surface s relationship to lights and cast shadows is taken into account To optimize memory usage the scanline approach is often broken into tiles The size of any given tile is based on the number and complexity of surfaces found with a particu lar area of
25. ions section see Figure 1 39 PROJECT RAYTRACING REFLECTIONS A list of the most critical attributes and their functionality follows Refractions Activates refractivity for the surface assigned to the material For the refrac tivity to be visible the material s Transparency attribute must be set above 0 Refractive Index Determines the degree of refractivity present If set to the default 1 0 no refraction occurs In the real world a refractive index is a number that indicates the change in the speed of light when the light ray crosses the boundary between two materi als For example water has a refractive index of 1 33 which means light slows by 25 per cent The actual equation is speed of light in vacuum speed of light in water or 1 0 0 75 which equals 1 33 The change in speed affects the perceived angle of the light rays which causes refracted surfaces to appear bent For example a straw placed in a glass of water appears bent below the water line Lists of real world materials and their refractive indexes are easily found on the Internet Refraction Limit and Reflection Limit Are local material overrides for the Reflections and Refractions attributes found in the Render Settings window The lower value between matching attributes determines the number of reflective or refractive rays that the surface assigned to the material is permitted to generate For example if Reflection Limit is set to 1 the assigned surface is a
26. itude of L ee Render camera view directions the subject is evenly lit and does not produce harsh shadows As such prod Grayed out areas uct photographers and videographers often employ light boxes As an added bonus light outside the box of the Resolution Gate boxes allow for the creation of a seamless background in which there is no obvious donor ndi horizon line 4 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Figure 1 4 Top The Light_Box cube Bottom A real world light box In this chapter you ll use the Light_Box cube to create large specular highlights and reflections in the plastic and metal of the headphones In Chapter 2 you ll have the chance to illuminate the scene by using the Light_Box cube s material attributes and the Final Gathering rendering option Material Types and Critical Attributes Materials sometimes referred to as shaders are small programs that determine the surface qualities of the geometry they are assigned to In common terms surfaces are described as rough smooth shiny dull and so on A material uses a shading model which is a math ematical algorithm that simulates the interaction of light with a surface Working with Lambert Blinn Phong Phong E and Anisotropic Materials The Lambert material is considered a parent material in Maya That is four other Maya materials Blinn Phong Phong E and Anisotropic inherit common attributes from the corre
27. l Off and or Specular Color values reduce the highlight intensity For the Ear_Cup geometry the following settings work well assuming the Key light s Intensity is set to 0 4 Color Dark gray RGB values 0 02 0 02 0 02 Diffuse 0 3 Eccentricity 0 15 Specular Roll Off 0 3 Specular Color Medium gray the default value Each material may require its own unique set of specular settings see Figure 1 18 Note that you can change the Specular Color to a nonwhite color For example the head phone s grommets are a semitransparent plastic By setting the corresponding material s Specular Color to a yellow gold the highlight becomes more subtle Figure 1 17 Headphones lit with an area light serving as a key The Diffuse and Color attributes of several materials are adjusted A sample file is saved as headphones step2 maon the DVD 18 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Figure 1 18 Eccentricity Specu lar Roll Off and Specular Color attributes of materi als are adjusted A sample file is saved as headphones step3 maonthe DVD For a color ver sion of the figure see the color insert While adjusting the specular quality of each material check each of the Reflectivity attributes For any material that need not be reflective set the Reflectivity attribute to 0 When raytracing is activated later in this chapter any material with a nonzero Reflectivity value will automatically ref
28. le the render on the right side of Figure 1 25 sets Diffuse to 0 2 Eccentricity to 0 16 and Specular Roll Off to 0 4 Render a test An impression of stitching is created 24 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Figure 1 26 Left Detail of ren der after addition of the Noise texture as a bump map Right Render after the adjustment of the 2d Placement Bump 2d and material node attributes A sample file is saved as headphones step8 maon the DVD The Foam surface which represents the material covering the headphone s built in speak ers can also benefit from a bump mapped noise To add such a bump follow these steps 1 Inthe Hypershade select the material assigned to the Foam_L and Foam_R surfaces The included sample scene files use the Foam material Open the material s Attribute Editor tab and click the checkered Map button beside the Bump Mapping attribute In the Create Render Node window click the Noise texture icon Render a test Blobbish pits appear on the Foam surfaces see Figure 1 26 To make the surfaces appear as if they are made of closed cell foam that possesses tiny bubble like air pockets adjust the 2d Placement node connected to the new Noise tex ture node Change the Repeat UV attribute to 10 10 to create smaller cells To further randomize the noise pattern select the Stagger check box To reduce the depth of the bump change the Bump 2d node s Depth
29. le place2dTexture is a long name Nevertheless 2d Placement and place2dTexture refer to the same node The Hypershade work area uses the long naming conven tion to label the node icons The Hypershade Create tab node list however uses the nice naming comvention In contrast to procedural textures several 2D textures are based on bitmaps imported by the user these include File Movie and PSD File When mapped to an attribute a bitmap based 2D texture is connected to its own 2d Placement utility node When a 3D procedural texture is mapped to an attribute a 3d Placement utility node is connected to the shading network The node is visible in each view panel as a green placement box see Figure 1 22 By default the box is placed at 0 0 0 and is 2x2x2 units in size The utility determines the color of each assigned surface point by locating the point s position within or relative to the placement box This process is analogous to a surface dipped into a square bucket of swirled paint or a surface chis eled from a solid cube of veined stone Hence the scale translation and PROJECT APPLYING TEXTURES 21 rotation of the placement box affects the way in which the texture appears across the assigned surface If the surface is transformed relative to the box or deforms over time the texture will change To avoid such a change it may be necessary to parent the 3d Placement node to the sur face More drastically you can convert 3D te
30. lect within the scene Adding Depth Map Shadows After the Key light is in place you can create shadows Follow these steps 1 With the Key light s Attribute Editor tab open expand the Shadows section Select the Use Depth Map Shadows check box 2 Render a test The shadow edge will appear jagged This is partially because of the low quality render settings Choose Window gt Rendering Editors gt Render Settings In the Maya Software tab of the Render Settings window change the Quality menu to Production Quality 3 Render a test The overall quality of the render is improved However the shadow remains jagged To remedy this you can raise the light s Resolution value For example in Figure 1 19 the Resolution is set to 2048 The higher the Resolution value the smoother the depth map shadow edge will appear However Resolution alone will not affect the hardness or softness of the shadow edge You can soften the shadow by adjusting the Filter Size attribute When adjusting the Resolution and Filter Size you can use the following rules of thumb e Fora hard edged shadow choose a high Resolution value and a low Filter Size value Fora soft edged shadow choose a low Resolution value and a high Filter Size value The Filter Size attribute blurs the shadow equally along its edge The Resolution attribute determines the pixel size of a depth map bitmap written to disc The bitmap is the view of the shadowing light written as a
31. llowed to reflect any ray that hits it so long as that ray has not been reflected previously If Reflection Limit is set to 4 an assigned surface is allowed to reflect any ray that hits it so long as that ray has been reflected previously three times or less If refractions and or reflections are missing from a surface when it renders yet the Reflections and Refractions attributes in the Render Settings window have high values raise the Refraction Limit and or Reflection Limit values Project Raytracing Reflections Thus far no surface in the headphones scene is creating reflections To create reflections you must select the Raytracing check box in the Maya Software tab of the Render Settings win dow After Raytracing is activated all surfaces are potentially reflective To alter this behav ior you must adjust the Reflectivity attribute of each material in the scene If you prefer that a surface does not reflect change the Reflectivity attribute of its assigned material to 0 To increase the strength of a surface s reflection raise the Reflectivity value of its assigned mate rial you can exceed the default limit of 1 0 by entering a higher value into the number cell Because reflectivity is also affected by Specular Roll Off and Specular Color those attributes may require adjustment Table 1 2 lists the recommended reflective surfaces and the cor responding Specular Color and Reflectivity settings the Specular Roll Off attributes were
32. mapped in the section Creating Custom Bitmaps earlier in this chapter 33 34 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Table 1 2 Recommended Reflectivity settings Figure 1 40 Final Chapter 1 render A sample file is saved as head phones step13 ma on the DVD Fora color version of the figure see the color insert SURFACE NAME SPECULAR COLOR REFLECTIVITY Slider_L R Mid gray 0 4 0 4 0 4 1 Junction_L R Mid gray 0 4 0 4 0 4 0 1 Cup_L R Mid gray 0 35 0 35 0 35 0 15 Grommet_L R Gold 0 5 0 4 0 0 2 Light_Box Floor material Default gray 0 5 0 5 0 5 0 3 Note that the Color of the material assigned to the Slider surface does not matter When Reflectivity is set to 1 0 the reflection obscures the surface color completely In this case the Slider surfaces are able to reflect the surrounding Light_Box as well as nearby parts of the headphones It s important to adjust the attributes within the Raytracing Quality section of the Render Settings window For this project a Raytracing value of 2 a Refractions value of 0 and a Shadows value of 2 is sufficient Refractions are not needed for the headphones model Additionally the Raytracing Options section of each material should be exam ined For this project a Reflection Limit of 2 is sufficient for each reflective material For more information on the raytracing attributes carried by a material and the Render Settings window see the prior
33. mbient light acts like bounced light in this case window light bounced off a floor a volume light functions as a point light but the illuminated surfaces must be placed within the light s volume shape Area The area light possesses a rectangular icon and can be scaled in either the X or Y direc tion Hence area lights can emulate a source that is transmitted through a plane with a fixed size For example an area light might re create sunlight arriving through a window or a bank of lightbulbs placed behind a rectangular marquee Area lights are the most physically accurate of the basic Maya light types As such the light intensity is affected by the distance and angle of the light icon in relation to lit surfaces Although an area light is represented by a rectangular icon it actually functions as an array of point lights This array causes the area light to be fairly soft Nevertheless area lights operate in one direction this is indicated by the small pointer extending from the light icon s center Ambient The ambient light is extremely soft and produces little if any variation in inten sity By default the light is a mixture of omnidirectional and directional rays The light s Ambient Shade attribute controls this mixture If Ambient Shade is lowered from the default 0 45 to 0 the light becomes equally intense at all points within a scene this leads to a flat toon look If Ambient Shade is raised to 1 0 the light r
34. me nodes are provided automatically and are necessary for basic rendering Others arrive as you add texture maps To view a shading network go to the Materials tab of the Hypershade RMB click a material icon and choose Graph Network from the marking menu The network is revealed in the work area see Figure 1 11 Initially several nodes are hid den To see the entire network select the visible nodes in the work area and click the Input And Output Connections button see Figure 1 9 earlier in this chapter It may be necessary to select all the visible nodes and click the button several times Within the work area you can delete node connections or add new ones For more information see Chapters 5 and 6 You can change the view within the work area by using the camera controls Alt key and mouse buttons If the work area becomes cluttered you can clear it by choosing Graph gt Clear Graph from the Hypershade menu Project Assigning Materials After examining the scene file the first important step to tex turing and lighting is the creation of new materials and their assignment to surfaces As such you must decide what types of materials to create In addition you must determine whether surfaces will share assignments After material assignments have been made you can adjust the materials Color and Transparency attributes Choosing Material Types PROJECT ASSIGNING MATERIALS 9 Figure 1 10 Selection buttons on
35. n of the bump texture A sample file is saved as headphones step11 ma Figure 1 36 Left Generic Specular Roll Off texture The tex ture is included as Generic_Spec tgain the ProjectFiles Project1 Textures folder on the DVD Right The result of the texture mapped to the ear cups and grommets A sample file is saved as head phones step12 ma PP eae ee eee ea Oe eee ee a eee ee ee eee eee ee ee ee Pee Pe Another material attribute that benefits from custom bitmaps is the Specular Roll Off By mapping the Specular Roll Off you can create the illusion that the surface is scratched smudged or slightly imperfect In this situation it is not necessary to make a specific map for a specific piece of geometry Instead you can create a generic bitmap that can be mapped to multiple materials and hence multiple surfaces For example you can map a low contrast grayscale noisy bitmap to the Specular Roll Off attributes of the materials assigned to the Junction_L Junction_R Cup_L Cup_R Grommet_L and Grommet_R surfaces see Figure 1 36 If the pattern found within the bitmap appears too similar between sur faces you can offset each instance by adjusting the Offset UV or Rotate UV attributes of the connected 2d Placement nodes If a surface is relatively small such as Grommet_L or Grommet_R you can use a portion of the texture by reducing the Repeat UV values below 1 1 Note that the Eccentricity and Specular Color
36. n a sufficient number of vertical lines when the texture has a greater number of pixels in the U direction PROJECT APPLYING TEXTURES 29 Figure 1 33 Left Custom color texture Right Ear cup rendered with logo Asample file is saved as head phones step10 ma A finished texture is included as Ear__ Cup_Color tgain the ProjectFiles Project1 Textures folder on the DVD a wae gt BEEN Figure 1 34 Left Leftmost column of faces of the Pad_L surface are selected in the UV Texture Edi tor Right Corre sponding faces are highlighted orange in the persp view panel This indicates the seam where the left and right sides of the UV texture space meet than in the V direction After the texture is mapped to the Bump Mapping attribute of the appropriate material it s necessary to adjust the Bump 2d node s Bump Depth and the mate rial s Diffuse and specular attributes For Figure 1 35 the following settings are used Bump Depth 0 2 a negative value inverts the bump result Diffuse 0 4 Eccentricity 0 2 Specular Roll Off 0 2 30 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Figure 1 35 Left A custom bump texture with vertical lines to repli cate bunched leather and short horizontal dashes to re create stitching The texture is included as Ear_ Pad_Bump tga in the ProjectFiles Projectl Textures folder on the DVD Right Detail of ren der after the additio
37. nd material To do so follow these steps 1 In the Hypershade create a new Blinn material and Surface Shader material 2 Inaview panel RMB click the Light_Box geometry and choose Face from the mark ing menu Shift click all the polygon faces along the floor If you accidentally select PROJECT ASSIGNING MATERIALS 11 an incorrect face deselect it by Ctrl clicking After all the floor faces are selected return to the Hypershade window RMB click the new Blinn material and choose Assign Material To Selection from the marking menu 3 Ina view panel select the entire Light_Box This deselects the floor faces and selects the remaining faces Return to the Hypershade and assign the selected faces to the new Surface Shader material Organizing the Hypershade As you work with the Hypershade it s important to keep the resulting contents orga nized The easiest way to achieve this is to name the materials clearly For example name each material after the real world substance it s supposed to replicate Thus Chrome and Foam are useful names You can also include the name of the surface a mate rial is assigned to For example you might use Plastic_Junction or Leather_Ear_Pad Avoid generic names that may become confusing in the long run For example it might not be clear which surfaces are assigned to Plasticl Plastic2 and Plastic3 One trick is to imagine that your scene p will be handed off to anoth
38. ng a Vehicle Part 2 For a demonstration of image plane use see Chapter 5 Layered Shader The Layered Shader material allows you to combine two or more materi als For a demonstration see Chapter 7 Hypershade Functionality Maya 2011 introduced a newly designed Hypershade window Window gt Rendering SF Editors gt Hypershade Nevertheless the win Bim dow s tabs menus and work areas remain virtu lt _ _ ally identical to earlier versions of the software In P Layered Shade 2 addition Maya 2012 uses the same Hypershade m ore Bade wpe ean Shader layout as Maya 2011 Figure 1 9 illustrates the key areas of the window ee In Maya 2011 and 2012 the Create tab is Surface Shader broken into two halves a rollout column and a Lise Background Ramp Shader node list column The rollout column filters what I D Env Pag SE appears in the node list column For example Light Fog ar age if you click the word Surface under the word Maya Volume Fog the node list column shows only standard Maya materials Figure 1 9 The Maya 2011 and 2012 Hypershade window with A Create tab ial rollout column which includes the Favorites Maya mental ray and Creating a New Materia Autodesk Materials 2012 sections B node list column which is filtered by selections within the Create tab rollout column C Input oo And Output Connections button D node tabs and E work area icons in the C
39. of the Maya Software tab of the Render Settings window see Figure 1 38 The number of times an initial ray is allowed to reflect or refract is controlled by the Reflections and Refractions attri butes For example if Reflections is set to 3 a ray is allowed to create three addi The Raytracing Quality section of tional reflection rays Along those lines any reflective surface is allowed to reflect the Maya Software tab in the Render any ray that hits it so long as that ray has been previously reflected two times or Settings window Y Raytrace Options Refractons Refractive Index 1 000 Refraction Limit 6 Light Absorbance 0 000 Surface Thickness 0 000 Shadow Attenuation 0 500 less Additionally you can control the number of raytraced shadows that appear in recursive reflections or retractions by setting the Shadows attri bute If Shadows is set to 2 the render creates one recursive raytraced shadow in any reflection or refraction If Shadows is set to 1 0 standard shadows appear but no raytraced shadows appear within reflections or refractions In Chromatic Aberration contrast depth map shadows appear in all reflections and refractions and Refiection Limit Reflection Specularity 1 0 Figure 1 39 The Raytrace Options section of a Blinn material are unaffected by the Shadows attribute For more information on raytraced shadows see Chapter 2 Blinn Phong Phong E and Anisotropic materials possess a Raytrace Opt
40. op view panel The three lighting scenarios are included as key ma key_fil1 ma and key_fill_rim main the ProjectFiles Project1 Reference folder on the DVD Point The point light produces omnidirectional rays originating from the light icon Point lights are similar to lightbulbs or other sources that have a small physically spherical shape Spot The Maya spot light re creates a spotlight found on a stage or motion picture set Thanks to its conical shape the spot light produces naturally divergent rays In general the light can emulate artificial sources that are close to the subject Because of the spot light s cone it has an identifiable falloff from 100 percent to 0 percent intensity The size of the cone is controlled by the Cone Angle attribute The softness of the cone edge is set by the Penumbra attribute which is 0 by default Note that the scale of the spot light icon does not affect its light quality LIGHTING TECHNIQUES AND Maya LIGHT TYPES Figure 1 15 Top Row Maya light types Bottom Row The corresponding real world lighting scenarios emulated by Maya lights From Left to Right A directional light re creates the parallel rays of an unobstructed sun a point light acts like a lightbulb with omnidirectional rays originating from a specific point a spot light simulates the divergent rays of a real world spotlight from film and stage an area light duplicates light arriving from a rectangular plane such as a window an a
41. ows each surface s material to be adjusted separately However the Hypershade may become difficult to manage if a scene is complex and contains numerous surfaces Assign a single material to every surface that shares the same look For example create a single Foam material and assign it to both the Foam_L and Foam_R surfaces This simplifies the contents of Hypershade but limits flexibility when adjusting attributes Either of these approaches is suitable for this project Should one approach prove limiting you can delete materials reassign materials or create new materials at any time To delete a material simply select its icon in the Hypershade Materials tab and press the Delete key If a material is deleted any surface assigned to it will not render until it is assigned to one of the other surviving materials Note that newly created primitives NURBS and polygon sur faces are automatically assigned to the Lambert1 material Although you can edit Lambert you cannot delete it You can assign a surface to a new or different material at any time Assigning Multiple Materials to One Surface When you assign a polygon surface to a material all the polygon faces are assigned to the same material However if you select individual faces before assigning the surface can be assigned multiple materials For example with the Light_Box geometry it would be pref erable to assign the floor to one material and the walls and ceiling to a seco
42. quality of the area light makes it suitable for product lighting Use the following steps to create and place the light 1 Choose Create gt Lights gt Area Light The new area light is placed at 0 0 0 Select the light and interactively scale it so that it s 10 10 20 units in X Y Z For greater preci sion you can enter values into the Channel Box Rename the light Key You can enter a new name through the top cell of the Channel Box while the light is selected 2 Position and rotate the light so that it is in front of and slightly higher than the Render camera icon see Figure 1 16 The light should point in the same direction as the Render camera The direction the area light is pointing is indicated by the pointer extending from the light s center Note that the Render camera is animated and moves in a short arc around the headphones Use the Timeline controls to see where the camera starts and stops 3 Render a test To do so choose Window gt Render ing Editors gt Render View and choose Render gt Render gt Render from the Render View menu At this point the render settings are set to low qual ity We will raise the quality after we add shadows Fine Tuning Material Attributes After you ve set the key light you can begin to fine tune additional material attributes First examine the overall brightness of the surfaces in the render If the surfaces are consistently too bright or too dark adju
43. r Node window click the Leather texture icon To simplify the node list column click the phrase 3D Textures under the word Maya in the rollout column After the Leather texture is selected three nodes are added to the mate rial s shading network a Leather node a Bump 3d node and a 3d Placement node To view the network follow the instructions listed in the Exploring Shading Net works section earlier in this chapter 3 Render out a test A leather like bump appears across the Head_Pad surface see Figure 1 23 At this point the leather pattern is small and too deep To reduce the bump depth open the Attribute Editor tab for the Bump 3d node Change the Bump Depth attribute to 0 3 Render a test 22 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Figure 1 23 Top Detail of ren der after addition of the Leather texture as a bump map Bottom Render after the adjust ment of the Bump 3d and Leather node attributes A sample file is saved as headphones step6 maon the DVD 4 Open the new Leather node s Attribute Editor tab Reduce the Cell Size to 0 8 to enlarge the overall size of the pattern Despite this adjustment vertical lines appear across the surface This is because of the regularity of the leather cells To defeat this change the Leather s Randomness attribute to 1 0 see Figure 1 23 Although the addition of the Leather bump map increases the realism of the head pad it does not c
44. r panel it closes and the selected color is placed in the swatch The Transparency attribute on the other hand should be left set to 0 black unless a surface calls for the namesake quality Of all the surfaces included in the headphones 12 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 scene file the grommets alone should be a semitransparent plastic As such set the cor responding material s Transparency color swatch to a medium gray Lighting Techniques and Maya Light Types Successful lighting in animation depends on a wealth of techniques developed for cinema tography and still photography This necessitates an understanding of Maya light types and the equivalent real world lights they emulate Understanding Product Lighting As mentioned earlier in this chapter light boxes light tents are useful for evenly lighting products that fit within their structure However the Light_Box geometry included in the headphones scene cannot provide illumination at this point although it will contribute to specular highlights and reflections We will activate the illumination capability of the Light_Box in Chapter 2 by using mental ray and Final Gathering In the meantime we will use other real world lighting techniques Figure 1 13 Top A model is lit by two lights placed on either side of the camera The left light carries a soft box Bounced light from the white walls works as a back light Bottom Left
45. re not seen by the rendering camera In Photoshop double click the Background layer in the Layers panel The New Layer window opens Enter a new name such as UV Snapshot into the Name field and click OK This converts the locked Background layer into a layer that you can reposition in the layer stack Choose Layer gt New gt Layer Double click the new layer to open the New Layer window Enter a new name such as Texture into the Name field and click OK LMB drag the UV Snapshot layer to the top of the layer stack Change the UV Snapshot layer s w Doc 3 00M 3 68M DOF blending mode menu from Normal to Screen The Figure 1 28 A UV snapshot of the Junction_R surface as seen in Photoshop _ The arrows point to several areas where polygon faces overlap in An example PSD file with this setup is included the UV texture space Screen blending mode allows the white lines of the snapshot to appear over the lower texture layer 26 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 as UV_setup psd in the ProjectFiles Project1 Reference folder on the DVD Proceed to paint on the lower texture layer Note that the general color of the texture does not need to be pure black Even though the junction is composed of black plastic you can add subtle scratches smudges or slight color variations see Figure 1 29 Figure 1 29 Left Detail of color variation added to the black representing the pla
46. reate tab The new material is added To create a new material click one of the material to the Materials tab To access the material s attri butes in the Attribute Editor click the material icon in the Materials tab if the Attribute Editor is closed double click the material icon To rename the material update the name cell at the top of the material s Attribute Editor tab Assigning a Material To assign a material to a surface select the surface RMB click the material icon in the Hypershade window and choose Assign Material To Selection from the marking menu You can also MMB drag the material icon and drop it on top of a surface in a view panel however this method is less precise and is prone to incorrect surface assignment When selecting a surface it s generally best to make your selections through the Hypergraph Hierarchy or Outliner windows If you select surfaces through a view panel do so while the Select By Object Type button is acti vated on the Status Line see Figure 1 10 If the Select By Hierarchy And Combinations button is activated instead you may inadvertently select a group node If a material is assigned to a group node all the group node s children automatically inherit the same material Exploring Shading Networks Any material you create is part of a larger shading network composed of multiple nodes The nodes are represented as square icons in the Hypershade node tabs and work area So
47. reate the illusion that the pad was constructed out of multiple pieces To cre ate the illusion that the edges of the pad are stitched you can apply a Grid texture as a bump map with the following steps 1 Select the Head_Pad surface and choose Window gt UV Texture Editor Note how the surface is split into multiple UV shells see Figure 1 24 The top shell contains the polygons sitting on the top of the pad The middle shell contains the polygons sitting on the bottom of the pad The bottom shell which takes the form of a square includes all the polygon faces along the forward and back edges of the pad To see which poly gon faces a shell includes RMB click in the UV Texture Editor and choose Face from the marking menu Proceed to select faces in the UV Texture Editor by either LMB clicking individual faces or LMB dragging a selection box around multiple faces The selected faces are highlighted in the view panels Note that each of the edge faces shares exactly the same UV texture space This means that every edge face will receive the same exact part of the texture assigned to the surface PROJECT APPLYING TEXTURES 23 2 Open the Hypershade Create a new Blinn material Name the new Blinn Leather_Pad_Edge or something equally appropriate Return to the UV Texture Editor Clear the face selection by clicking on an empty area of the UV space LMB drag a selection box around the bottom square shell All the edge faces are selected Re
48. rom the view panel menu To manipulate the persp camera select the persp node in the Hypergraph or Outliner and use the standard transform tools You can also interactively move the camera with the Alt key and mouse buttons in a perspective view panel H H T T ii H i Sane ee rete ee eee Eg eee TT i ji ii Bi ll Il T 1 n Figure 1 2 Left The UV Texture Editor view of the Ear_Pad_R surface A single UV shell occupies the entire UV texture space The dark gray area represents the 0 to 1 UV range whereby a texture is tiled one time Right The UV Texture Editor view of the Ear_Cup_R surface Two UV shells fill a portion of the UV tex ture space In this case UV points are selected and appear as green dots in Maya The render resolution of the scene file is set to 640x360 which View shang Lighting Show Renderer Panes Da CET EE OCL E ERE is one half the size of HD 720 1280x720 This is suitable for test renders We will raise the resolution to 1280x720 toward the end of this chapter In addition the anti aliasing render quality will be switched from low quality to high quality Examining the Light_Box Geometry The headphones are surrounded by a large cube named Light_ Box Real world light boxes or light tents are small structures covered with fabric or other translucent material that diffuses Figure 1 3 incoming light see Figure 1 4 Because the diffused light arrives from a mult
49. section of this chapter The addition of raytracing concludes the first part of Lighting and Texturing a Product As such your render should look similar to Figure 1 40 In Chapter 2 we ll add an additional light change the shadow type switch to the mental ray renderer activate Final Gathering and fine tune the materials and textures
50. so known as back lights or hair lights When a rim light is used to fill in the dark side of a person s face it is known as a kicker Figure 1 14 is included as an example of lighting in Maya that adds a key fill and rim light The color and shadow quality of each light is determined by the real world light source it s attempting to replicate For example if a Maya directional light is acting as a midday sun it should arrive from a high angle create hard edged shadows and carry a color that is slightly blue Light replication is discussed in more detail throughout the remaining chapters of this book Understanding Maya Light Types Maya provides six basic light types see Figure 1 15 This chapter and Chapter 2 use an area light and volume light and the remaining lights are utilized throughout the remain ing chapters The key qualities of each light type follow Directional The directional light creates parallel rays As such the light has direction but not position Hence the position of the light icon will not affect the light quality Directional lights are suitable for emulating the sun or other light sources that are a great distance from the subject 13 14 CHAPTER 1 TEXTURING AND LIGHTING A PRODUCT PART 1 Figure 1 14 Top Left Mannequin lit by a key light Top Right Mannequin lit by key and fill Bottom Left Mannequin lit by key fill and rim Bottom Right Positions of all three lights as seen in a T
51. sponding Lambert node see Figure 1 5 MATERIAL TYPES AND CRITICAL ATTRIBUTES 5 The shared attributes include the following Color Color determines its namesake You can enter specific red green and QRS Color a blue values by clicking the color swatch and updating the Color Chooser EERE 7 window For more information on the Color Chooser window see the aries z Adjusting Colors and Transparency section later in this chapter ee Dieese 0 200 7 Transparency Much like Color Transparency uses a color swatch By zs Tranalucence Depth 9 500 n default Transparency employs a scalar grayscale range in which black Translacence Focus 0 500 J is opaque and white is transparent However you are free to choose any Figure 1 5 color value through the Color Chooser window Attributes shared l l l _ by Lambert Blinn Ambient Color Ambient Color represents diffuse reflections arriving from all other sur Phong Phong E faces in a scene as well as reflections from participating media particles suspended in se ee a materials air such as dust smoke or water vapor To simplify the rendering process the diffuse reflections are assumed to be arriving from all points in the scene with equal intensities In practical terms ambient color is the color of a surface when it receives no direct light A high Ambient Color value will reduce the contrast of an assigned surface Incandescence Incandescence creates the illusion
52. st the Key light s brightness To do so open the light s Attribute Editor tab with the light selected press Ctrl A and change the Intensity attribute value If individual surfaces are too bright or too dark adjust the corresponding material s Diffuse attribute Lower Diffuse values produce darker surfaces If necessary further adjust each material s Color attribute For example in Figure 1 17 the Key light s intensity is set to 0 4 while several materials have had their Diffuse and Color values lowered PROJECT CREATING LIGHTS AND SHADOWS 17 As you adjust the materials render out additional tests in the Render View window To save time render out only the region of interest You can define a region by LMB dragging in the Render View render area to form a red region box After releasing the mouse click the Render Region button Aside from the Color and Diffuse attributes it s important to adjust attributes control ling specular highlights For example the render shown in Figure 1 17 features black plas tic parts with intense specular highlights The highlights reduce the overall contrast for the plastic surfaces and thus make them appear milky In particular the Ear_Cup geom etry carries large areas that verge on pure white To defeat the overly intense specular high lights adjust the Eccentricity Specular Roll Off and Specular Color attributes Reducing Eccentricity creates a smaller highlight Lower Specular Rol
53. stic The contrast is exaggerated for print The actual texture variation is more subtle Right Photo of screw head pasted twice into texture as seen in Photoshop A finished texture is included as Junction_Color tga 4 To add additional realism feel free to cut and paste from photo bitmaps For example in the ProjectFi les l l Project1 Textures the junction geometry includes two cylindrical holes that represent the locations of folder on the DVD screws Instead of painting screw heads by hand cut and paste from a photo bitmap of a screw you can take the photo yourself or find one through a stock photo or 3D texture website To cut and paste choose File gt Open and retrieve the photo bitmap Switch to the opened photo bitmap by clicking on the top bar of its window Using the Lasso tool draw a selection marquee around the screw head Choose Edit gt Copy Switch back to the texture you started with Choose Edit gt Paste Press Ctrl T to reveal the transfor mation handle Interactively scale position and rotate the pasted screw head into loca tion over a screw hole indicated by the UV snapshot see Figure 1 29 5 To create a specific logo on the side of the junction you can use Photoshop s Type tool or cut and paste from a bitmap that already carries text You can leave the text a solid color On the other hand you can add color variation to make the text appear more complex For example to give the sense that
54. that the surface is emitting light The color value of the Incandescence attribute is added to the color value of the Color attri bute thus making the material appear brighter You can use the Incandescence attribute to contribute light to a scene when using the mental ray renderer and the Final Gathering option this is demonstrated in Chapter 2 Bump Mapping At the point of render bump maps perturb surface normals along the core of a surface the central section facing the camera They do not however affect the surface s silhouette edge For example in Figure 1 6 a primitive sphere is assigned to a bump mapped material While the core of the sphere appears craggy the sphere s silhouette edge remains per fectly smooth Nevertheless the bump effect can often sell the idea that a surface is rough When the Bump Mapping attribute is mapped middle gray values 0 5 0 5 0 5 on a 0 to 1 0 RGB scale have no effect Higher values cause peaks and lower values cause valleys to form For a demonstration of the bump effect see the section Procedurally Mapping Bumps later in this chapter Diffuse The term diffuse refers to that which is widely spread and not concentrated Hence a real world diffuse surface Figure 1 6 appears matte like and does not create highlights or specular hot spots This is because A bump mapped sphere renders with a craggy core anda For example paper and cardboard are diffuse surfaces In Maya
55. turn to the Hypershade RMB click the new Blinn node and choose Assign Material To Selection Although the pad s UV texture space contains the faces for the entire pad only the selected edge faces are assigned to the new Blinn The old material s assignments of the remainder of the pad are not changed 3 Open the new Blinn node s Attribute Editor tab Change the attributes to match the material assigned to the remain der of the pad The included sample scene files use the Leather_Head_Pad material Click the checkered Map Figure 1 24 button beside the Bump Mapping attribute In the Create TRE ene or EEA E AUNAR Render Node window click the Grid texture icon Grid Bump 2d and 2d Placement nodes are added to the Blinn s shading network Render a test Small divots appear along the pad edges see Figure 1 25 Figure 1 25 Left Detail of ren der after addition of the Grid texture as a bump map Right Render after the adjustment of the 2d Placement and Blinn node attributes A sample file is saved as headphones step7 maon the DVD 4 To refine the bump pattern open the new 2d Placement node s Attribute Editor tab Change the Rotate UV attribute to 45 This creates diagonal grid lines Open the Grid node s Attribute Editor tab Change UV Width to 0 3 0 3 This thickens the grid lines so they will become more visible To further exaggerate the bump readjust the Blinn node s attributes For examp
56. xtures to 2D textures through the Convert To File Texture tool 3D tex tures include Brownian Cloud Crater Granite Leather Marble Rock Snow Solid Fractal Stucco Volume Noise and Wood Project Applying Textures After basic material attributes are adjusted under the Key light you can begin adding textures Both procedural textures and custom bitmap tex tures will lend the render greater complexity Because textures will add fine detail to the various surfaces it s neces sary to increase the render resolution to accurately gauge the result Open the Render Settings window and change the Presets menu in the Image Size section to HD 720 Procedurally Mapping Bumps Figure 1 22 Top A 3d Placement utility node auto matically named place3dTexture1 con perfectly smooth To defeat this perfection you can map Bump Mapping nected to a Solid Fractal texture node Bottom The corresponding placement box displayed in a view panel At the present stage of this project the surfaces of the headphones appear attributes with various procedural textures For example to add a leather like bump to the Head_ Pad geometry follow these steps 1 Open the Hypershade window and click the material assigned to the Head_Pad sur face The material is named Leather_Head_Pad in the included sample scene files In the material s Attribute Editor tab click the Bump Mapping attribute s checkered Map button 2 Inthe Create Rende
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