LightWave 3D 8 Texturing phần 10 pps

Summary of Tips for Creating Wooden Surfaces • Finding and using suitable photographs for using in your textures is usually quicker than painting wooden images. • Make sure that the direction of the grain in the wood is correct. For example, you wouldn’t have the grain running horizontally across the width of a long plank — the grain would run along the length of it. • For lacquered, finished wood objects, model an additional layer surrounding the wood and shade it as you would clear plastic. • For older or dry woods (such as trees, crates, driftwood, or rough planks), use little to no specularity and no glossiness. Using reflection for highlights on dry wood is a waste of rendering time, so stick to specularity in small quantities. • If you are working on a tree with coarse, chunky bark, use displacement mapping for the bark instead of just a bump map. A bump map will most likely end up looking fake. • Details such as fingerprints make lacquered wood duller. Add dark streaks from fingerprints to your reflection or specular maps to lessen the effect in those areas. • When lacquered wood has just been polished, it shows streaks of variations in the reflection map, usually in circular patterns, since this is the pattern in which most people tend to polish. If you really want to be a detail freak, add these patterns to your reflection maps. • Whatever you do, don’t use that cedarfence.jpg image that every single 3D user on the planet has used at some stage or another as a wood texture. It has been used to death, and it is about time that it is retired from its long-standing run in the 3D world. 443 ·········································WoodSurfaces Quick Tutorials Chapter 22 Organic Surfaces Organic surfaces are probably the toughest surfaces to create, because not only do you have to make them look realistic, but you also need to make them look alive, and that is by far the trickiest thing to do in texturing. I tried, I really did, to write a step-by-step tutorial on painting human skin for this book, but failed miserably. You cannot give somebody a paint-by-numbers tutorial on painting human skin because a lot of artistic technique is involved, and it requires an approach and a certain delicacy that cannot be taught, only developed over time and with practice. And the same really applies to any organic surface. This is because organic surfaces require a subtlety that can be demonstrated but not laid out in a series of instructions. I cannot teach you to be an artist; I can only show you my own examples and hope that by observing, you will understand what it is that is required and subsequently develop your own technique of creat- ing what you know is needed. As I have said time and time again, references are essential when creat- ing textures, and this is probably the single most important piece of advice I can give you when it comes to organic substances. If you have lots of refer - ences, you simply cannot go wrong. Paint what you see and paint what you need. This is a simple philosophy, but it usually requires a lot of work. By now you should have a clear understanding of why and how surfaces work, and what you need to manipulate in your settings in order to achieve certain effects. If, for any reason, you are still trying to get a handle on texturing, I rec - ommend that you stick to simpler surfaces until you have a finer grasp of them before trying to tackle organic surfaces; otherwise, there’s a good chance you will simply end up disappointed. Organic surfaces, above all, require patience, an artistic eye, extreme attention to detail, and very good painting and color skills. There are two tutorials in this section. The first is that of an eyeball. The eyeball is a step-by-step tutorial; however, it does not involve texture painting (I have supplied an iris image for you to use). I included this tutorial solely because eyes are one of the most essential parts of a character, and all too often I see dead-looking eyes in digital characters. 444 The second tutorial is a guide to human face painting. The same ideas can be applied to any type of skin. As you will see, it all comes down to observation and recreation, with a large dose of careful painting and use of color. Good luck! Organic Tutorial 1: An Eyeball Eyes are the windows to the soul. Well, some people say so anyway. By creating eyes that have a sense of depth, we instantly impart life to our characters, and this is why it is so important to ensure that your character’s eyes, whether they are human, alien, or animal, are believable and have a spark of life in them. The first essential thing for eyes is to model them with details. At the very minimum, model your eyeballs in three parts: the inner eyeball, the outer liquid layer covering the inner eyeball, and the lens. Modeling your eyes to have these three parts is the first step to a suc- cessful eyeball. I am supplying an eyeball model for this tutorial anyway, so feel free to use it as much as you like on all your characters if you’ve simply been using spheres up to now. Some people also like to model the actual pupil separately as well, but that is only really necessary when you are going to be doing a lot of close-up animation and want to have control over animating the size of the pupil according to lighting changes. 1. Load up the 7.3-Eyeball.lws scene from the companion CD-ROM. You’ll see a lonesome eyeball staring up at you. 445 ········································Organic Surfaces Quick Tutorials Figure 22-1 As always, I have already set up Image World in this scene to create an environment with an HDR image so that the eyeball has something to reflect. I have already painted the textures for this eyeball, but let’s quickly take a look at each of them. (You’ll find the Photoshop file of this eyeball tex - ture with a few different colored irises on the companion CD-ROM.) First, let’s examine the color texture. It really couldn’t be simpler. I took a photo of an iris, worked it a bit to remove lighting (this involved cloning areas onto the areas where there was light), and posi - tioned it correctly onto the image. If you look at the Photoshop file I have included on the CD, you’ll find a blue and a brown variation of this iris as well. Immediately surrounding the iris we have a white area with faint pink coloring in certain areas, just to offset the white slightly. And surrounding the white is a pink border, with veins of varying inten- sity. The pink edges and the veins are on separate layers and can therefore be adjusted separately. Please feel free to go ahead and alter these to your tastes. Secondly, we have a bump map. As you can see in Figure 22-3, the bump map is solely for adding a bit of bump to the veins on the eyeball. Again, the veins are on separate layers so they can be adjusted to suit your tastes. 2. Back to the scene. I have already added the textures to the eyeball’s “eyeball inner” surface, which is the actual inner sphere forming the bulk of the eye itself. Set up the rest of the basic parameters as follows: Diffuse: 50% Reflection: 3% Translucency: 50% Leave all the other values as they are. This creates a reasonably fleshy eye - ball that is somewhat reflective. Having a bit of reflection on the inner eye helps to create a deeper look to it since it appears to form more layers. 3. The eyeball lens and the outer eyeball surfaces require the same set - tings, so all we need to do is set one up and then copy it to the other. 446 Chapter 22 ··········································· Part 7 Figure 22-2 Figure 22-3 Select either one of them and let’s get started. Set up the basic parame - ters as follows: Color: 255, 255, 255 (pure white) Diffuse: 40% Specularity: 80% Glossiness: 60% Reflection: 0% (we’ll map this in a moment) Transparency: 0% (we’ll be map - ping this one too) Refraction Index: 1.2 Make sure that both Smoothing and Double Sided are checked. 4. Open the Reflection Texture Editor by clicking on the “T” button next to it. Change the default layer to a gradient tex- ture by selecting Gradient from the Layer Type pull-down list at the top right of the panel. Change the gradient’s Input Parameter to Incidence Angle. See Figure 22-4. 5. Select the top key on the gra- dient ramp and change its Value to 5%. Now create a sec - ond key at the bottom of the ramp and set its Value to 1%. This applies a very low level of reflectivity to the surface; however, even such a low level is sufficient for this example. See Figure 22-5. 6. Open the Texture Editor for Transparency. Change this default layer also to a gradient texture and select Incidence Angle as the Input Parameter. Select the top key that was created on the gradient ramp and change its Value to 80%. Create a second key at the bottom of the ramp and change its Value to 100%. See Figure 22-6. 447 ········································Organic Surfaces Quick Tutorials Figure 22-4 Figure 22-5 7. Copy this surface to the other surface (either the lens one or the outer eyeball one, depending on which one you just set up) by right-clicking on its name and selecting Copy, and paste the settings into it by right-clicking and selecting Paste. Your surfaces are now set up. Render- ing the eyeball should give you something like Figure 22-7. And now you have a decent eyeball for your characters. Depending on the lighting in your scenes, you may find that you’ll have to change some of the parame - ters from scene to scene (especially the Diffuse parameter), but as I mentioned before, it is the modeling of the eyeball that makes all the difference. Organic Tutorial 2: A Human Face I chose a pirate for this exercise because such a character has the potential to have many of the kinds of details that you’ll encounter when you texture heads, such as scars, pimples and blemishes, wrinkles, gaunt coloring, and so on. Basically he’s the ultimate exaggeration of skin texturing! So let’s get started. When I’m texturing skin I like to start off the entire process by taking the model into Layout and setting up the lighting and the basic shading of the model. We all know what lighting is but let me quickly explain what I mean by shading. Shading, as discussed previously, is the stage when I set up all the basic surface parameters — diffuse, specularity, reflection, translucency, and colored highlights — to get the basic look of the surface simply by assigning overall values to each so that it more or less 448 Chapter 22 ··········································· Part 7 Figure 22-6 Figure 22-7 begins to look like skin. I also add a rough procedural grain to the skin to give it some texture. While I am doing this I also set up my lighting because the interaction between the surface and the lighting is very important for realism. For this example I used an area light as the main light, with two spotlights (one behind, one to the side) and Backdrop Only radiosity to soften the overall lighting. I mix a little bit of red and blue into the lighting as these colors go well with skin. You’ll find that when working with skin, the shading values you assign can vary quite a bit depending on the lighting setup. There is no foolproof surface setting for each surface attribute that will always work in any light - ing situation. However, what generally does always work is to make the skin look overly soft to begin with. Take a look at the flesh on your cheeks and try to make the entire head look like that — in other words, make it look really soft, fleshy, and, well…almost squishy. You can create specular and reflec - tion maps later on to “harden” the areas that shouldn’t look that soft. Once you’re happy with the way that the skin looks in the shading ren - der, it’s time to start painting your texture maps. Ideally, the textures you paint should serve only to add details to the shading you’ve already set up. In other words, we’ll make textures to add color variation, blemishes, wrin - kles, etc., as well as variations in the actual surface attributes like specular, translucency, reflection, etc. I’ve already set up my UV map for the head using a cylindrical map on the y-axis that I have edited to eliminate stretching. I then export the UV viewport out of Modeler. 449 ········································Organic Surfaces Quick Tutorials Figure 22-8 Fire up Photoshop (or whatever you use for painting textures) and let’s get going. I generally start off my texture painting by doing the color map. This is purely out of habit — there is no reason why you can’t start off with any of your other attributes. I like doing the color map first simply because I like to start off by establishing the basic look of whatever I am creating textures for, and for me the most logical choice is color. But start off with whatever you feel most comfortable with. I start off my color map by creating a flat skin tone and then adding sub - tle variations to it to break up the monotony of the single color. A nice quick way of creating subtle color variation is to create some noise using the Noise filter. Create some fairly low-level noise (don’t use the Monochrome option) and then blur it a lot. Skin color can be a tricky thing to paint because in reality skin is actu - ally very plain. It gets most of its perceived tonal variations from two things: its environment (i.e., reflections) and what’s going on beneath it. Generally we’ll fake what’s going on beneath it by adding those particular tones to the color map, and create a reflection map for the surface in order to allow it to reflect its environment a little. So in order to fake what’s going on beneath the surface, we basically have to create the illusion of blood beneath the skin, and this means that we add red and blue tones, particularly in the cheeks and just below the eyes where the skin is a little thinner. The bridge and tip of the nose tend to get a little redder as well. 450 Chapter 22 ··········································· Part 7 Figure 22-9 The key to creating successful skin textures lies in subtlety. A subtle buildup of tones creates a far more realistic look than big splotches of color. For this reason I tend to use my airbrush on a low opacity (usually around 30%) with 0% hardness (soft edges), and slowly build up my tones by gradu- ally painting over and over certain areas until the blending looks right. I use a Wacom for most of my painting, which does make this a little easier since you have a lot more pressure control, but using an extremely low opacity with a mouse can create exactly the same effect. I now want to make the scar and some blemishes for the face. I start off with the scar, sketching its shape out in gray using the airbrush and then the Soft Light blending mode, and taking the opacity of the layer down to create the right blend of scar tissue with the underlying skin texture. See Figure 22-11. I sketch some faint vein details and some subtle blue tones around this area as well, to create a little more “activity” in that area. Each detail is on its own layer. I also draw some blemishes and pimples on their own layers and find the right blending for them, in this case using the Color Burn blending mode. At this point I also add some more detail to the lips, to give them some nice tonal variations and make them look a little fleshier. 451 ········································Organic Surfaces Quick Tutorials Figure 22-10 Now that I have some blemishes, pimples, and a scar, it’s time to focus on the eye areas. These areas are important because the eyes are generally the first part of a CG character that your viewers are going to focus on, so you have to ensure that they look good. I start off by adding even denser layers of blues and reds to create dark, purplish flesh below the eyes. This is to create a sickly, gaunt look for the character. Having dark rings under the eyes also helps to portray a creepi - ness and dangerous look for the character. I also add some very subtle wrinkles to this area. 452 Chapter 22 ··········································· Part 7 Figure 22-11 Figure 22-12 [...]... command, 360 Set UV Value command, 365 shaders, 84 -85 BRDF, 48, 86 -89 Edge Transparency, 89 -90 Fast Fresnel, 94-95 G2, 107 -114 gMIL, 105 -106 Halftone, 96-97 Interference, 97-99 LightWave built-in, 85 -106 Real Fresnel, 95-96 Super Cel, 99 -103 Surface Baker, 90-94 Surface Mixer, 104 -105 Thin Film, 103 -104 third-party, 107 -115 Z Shader, 104 shading, 116-117 models, 84 Shadow Density (Alpha Channel option),... blending with, 302 creating and using images with, 219-220 anisotropy, 48- 49 with the BRDF shader, 88 -89 with the G2 shader, 114 area lights, 16-17 atlas mapping, 343-3 58 Automatic Sizing option (Texture Editor), 280 B backlight, 19 Blending Mode setting (Texture Editor), 271-277 Bloom filter, 390-391 BodyPaint 3D, 254-256 BRDF shader, 48, 86 -89 Brick procedural texture, 142-143 brightness, 35-36, 265 brush,... renaming, 26 saving, 26 T Texture Amplitude option (Texture Editor), 287 - 288 Texture Antialiasing option (Texture Editor), 287 Texture Axis option (Texture Editor), 279 Texture Color option (Texture Editor), 139 Texture Displacement blending mode (Texture Editor), 277 Texture Editor, 269- 288 Falloff tab, 282 - 285 Position tab, 281 - 282 ... parameter, 174 Smoky procedural texture, 156-1 58 Smooth Threshold option (Surface Editor), 28 4 78 Smoothing option (Surface Editor), 28 Soften Reflections filter, 396-397 using with Special Buffers, 77 Special Buffers, 72-77 specular map, creating, 46-47, 235-2 38 specular reflection, see specularity specularity, 44-49 anistropic, 48- 49 tinting, 47- 48 spherical mapping, 310- 313, 331-343 spotlights, 15-16 Spread... 294-295 in UV maps, 374-3 78 subdivision distortion in UV mapping, 373-374 subsurface scattering, 62-63, 113 Subtractive blending mode (Texture Editor), 273 Super Cel shader, 99 -103 Surface Baker shader, 90-94 Surface Editor, Advanced tab, 69 -80 edit modes, 24-25 Environment tab, 80 -84 filtering options, 25-26 opening, 23-24 preview options, 26- 28 Surface Mixer shader, 104 -105 Surface Opacity (Alpha... 58- 59 creating with gradients, 191-195 Fast Fresnel shader, 94-95 Real Fresnel shader, 95-96 Full Precision Blur filter, using with Special Buffers, 75-76 G G2, 107 -114 Gamma option (Image Editor), 266-267 glossiness, 49-50 glossiness map, creating, 2 38- 240 glow, 78 using with luminosity, 42-43 gMIL Occlusion shader, 105 -106 gradient ramp, 172 gradients, 172-179 blending with, 2 98- 301 tutorials, 180 -195... texture, 147-1 48 cubic mapping, 3 18 Cull Map command, 361-362 Cyclone procedural texture, 167-1 68 cylindrical mapping, 302-306, 331-343 D Deep Paint 3D, 252-254 Delete Vertex Map command, 361 Dented procedural texture, 1 68- 169 Difference blending mode (Texture Editor), 274 diffuse, 37-39 and reflection, 54-55 diffuse map, creating, 234-235 Diffuse Sharpness option (Surface Editor), 80 diffusion, 38 discontinuity... Aluminum 1.44 Amber 1.546 Amethyst 1.544 Aquamarine 1.577 Asphalt 1.635 Benzene 1.501 Bromine (liquid) 1. 18 Calcite 1. 486 Carbon dioxide (gas) 1.000449 Chalk 1. 510 Chlorine (gas) 1.0007 68 Chlorine (liquid) 1. 385 Cobalt blue 1.74 Cobalt green 1.97 Cobalt violet 1.71 Copper 1 .10 Copper oxide 2.705 Coral 1. 486 Crystal 2.00 Diamond 470 1.661 Bronze 2.417 · · · · · · · · · · · · · · · · · · · · · · · · · · ·... references, 11-12 reflection, 50-55 and diffuse, 39, 54-55 Reflection Blurring option (Surface Editor), 84 reflection map, creating, 240-243 Reflection Options (Surface Editor), 81 -82 refraction, 56- 58 index, 57, 470-472 Refraction Blurring option (Surface Editor), 84 Refraction Options (Surface Editor), 82 -83 477 Index · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·... Render Outlines option (Surface Editor), 78 resolution, image, 2 08- 211 RGB images, 220 RGB color space, 32-33 Ridged Multi-Fractal procedural texture, 171 rim light, see backlight Ripples procedural texture, 155-156 Rotation tab (Texture Editor), 282 S Sasquatch, 3 98- 401 saturation, 35, 266 Scale tab (Texture Editor), 139-140, 280 - 281 seamless textures, creating, 2 18- 219 seams, in cylindrical/spherical . value of gray (1 28, 1 28, 1 28) so that I can create a suitable range of both light and dark details over it to create the details necessary for the bump map. Remember that with LightWave, lighter. that was created on the gradient ramp and change its Value to 80 %. Create a second key at the bottom of the ramp and change its Value to 100 %. See Figure 22-6. 447 ········································Organic. gaunt coloring, and so on. Basically he’s the ultimate exaggeration of skin texturing! So let’s get started. When I’m texturing skin I like to start off the entire process by taking the model into