LightWave 3D 8 Texturing phần 5 pptx

Chapter 9············································ Part 3 Change the Input Parame - ter to Slope. When you create this gradient, a key is automati - cally created for you at the top of the gradient ramp. We can leave this key exactly as it is. Click a little way below this top key to create another key. Change its Alpha value to 90% and the Parameter value to 0.2. We are now creating snow that lies on horizontal and slightly sloping areas of the mountain object. Click again just below the second key to create a third one. Make sure that its Parameter value is 0.3 and change its Alpha value to 0%. This now makes the snow completely disappear as the object slopes downward. If you render your object now, you should get something that looks like Figure 9-41. NOTE: I have set the lighting up in the scene to use pure radiosity to light it. If you find that the render is too slow for your machine, simply go to your Global Illumination panel and switch the Radiosity option off, then set the Global Intensity value back to 100%. Okay, so we have a mountain that now has some decent snowfall on it. How about adding a touch of greenery along the bottom of the slopes to show some forest areas or just some grassy knolls? This will help to break up the monotony of the brown color on the slopes. 5. Create a new procedural layer (below the Slope gradient layer), and select Turbulence (my most favorite procedural for doing practically any - thing). Set its color to a nice medium green with the following RGB values: 35, 80, 25. Set up the actual texture as follows: Frequencies: 5 Contrast: 90% Small Power: 1.0 188 Figure 9-40 Figure 9-41 ············································Gradients Creating Textures Set the Scale values on the Scale tab to 500 mm for each axis, as shown in Fig - ure 9-42. The problem with this procedural is that right now it covers the entire surface. We only really want it along the foothills of the moun - tain, so we need to have it only growing up to a certain height. This is where the Y Distance From Pivot Point gradient comes in handy. 6. Create a new gradient layer by clicking on the New Layer button and choosing Gradient. Place this gradient above the procedural layer, so that it sits between the procedural and the Slope gradient layers. Change the Input Parameter of this gradient to Y Distance From Pivot Point. Now, if you select the mountain object in Layout, you’ll notice that its pivot is exactly at the bottom of the object, on the ground. 189 Figure 9-42 Figure 9-43 Chapter 9············································ Part 3 So this particular gradient will take its information and allow variations according to the distance along the y-axis from that pivot point. Let’s set up the gradient so that it will mask the procedural, and allow it to show only along the base of the mountain. 7. Change the Blending Mode of the layer to Alpha. This is because we want this gradient to act as a mask for the underlying procedural texture. NOTE: Refer to Chapter 13 for more information on blending lay - ers correctly and effectively. Right now, the entire gradient is white, so it is not masking anything, as the white areas of an alpha layer are the areas that allow the underlying layer to show through. Since black areas mask the underlying layer, we need to mask the procedural as it climbs higher along the y-axis of the object. To do this, we need to first specify the maximum height that we would like the green areas to grow up to. 8. Click in the field at the bottom of the gradient ramp where it says End and enter a value of 15 m. Now create a key at the bottom of the ramp (ensure that the Parameter value is set at 15 m), and set its color to black (RGB 0, 0, 0). This allows the green pro- cedural texture to be visible only up until it reaches a distance of 15 m above the pivot point at the base of the object. And that pretty much does the trick! Rendering your scene out now, you should get some - thing that looks like Figure 9-45. Mmmm…, reminds me of mint choco - late for some reason. And there you have it! A snowy mountain peak. Simple, yet effective for those long-distance shots that call for far - away snowy peaks. 190 Figure 9-44 Figure 9-45 ············································Gradients Creating Textures Tutorial 3: Simulating the Fresnel Effect in Glass Although LightWave does include two differ - ent Fresnel shaders (discussed in the Shaders section of Chapter 5) to create this effect, we can also create it very simply using gradients. This tutorial demonstrates setting up a glass surface using gradients to simulate this effect on the LightWave logo. The Fresnel effect is the phenomenon that we observe in the real world whereby the amount of reflection that we see on a sur - face differs according to the angle that we view it at. This effect is not only found in transparent substances, but in anything that is reflective to any degree. Now let’s get down to business and make it ourselves! 1. Open up the 3.4.4-Tutorial_03.lws scene file from the companion CD-ROM. The scene should load with a LightWave logo (3.4.4-LW_ Logo.lwo) placed in the center of the camera view. Because we are working with a glass surface, we need to give the object an environment to reflect. Check that the Beach_Probe HDRI image 191 Figure 9-46 Figure 9-47 Chapter 9············································ Part 3 is loaded in the scene and has been added to the Image World in your Back - drop options (Ctrl+F5). 2. Okay, now that we know that the scene is all ready to be worked with, let’s go to the Surface Editor. If you have ever tried making glass surfaces before, you may know that they can be pretty darn tricky sometimes. Select the surface “logo surface” in the Sur - face Editor, and enter the following amounts for each of the basic attributes: Color: 0, 0, 0 (pure black) Luminosity: 0% Diffuse: 0% Specularity: 30% Glossiness: 20% Reflection: 0% Transparency: 0% Refraction Index: 1.5 Translucency: 0% Ensure that Smoothing and Double Sided are on. You are probably wondering why we have entered in values of 0% for the reflection and transparency chan - nels when we are making reflective glass! The reason for this is that when we create the gradients in each chan - nel, we do not need to enter in an overall amount, as LightWave will take all its input for each channel from the gradient itself. 192 Figure 9-48 Figure 9-49 ············································Gradients Creating Textures 3. Now that we have deter - mined all the basic attributes, we need to create the gradients. Go to the Transparency channel and open its Tex - ture Editor by clicking on the T button. Create a new gradient layer in the Texture Editor, and set the Input Parameter of the gradient to Incidence Angle. 4. Now, create a new key at the bottom of the gradi - ent. Make sure that the Parameter value for this key is 90.0. Leave its Value at 100%. See Figure 9-51. This key represents any part of the sur- face that is facing us at 90°, in other words, the part of the logo that faces us straight on. Having this value set to 100% means that these parts of the surface will appear to be 100% transparent when we look at the logo. 5. Go back to the top key at Parameter 0, and change its Value setting to 0%. This should make the color of this key in the gradient go to black. See Figure 9-52. This key represents the parts of the sur - face that face us at an angle of 0°. These are the areas that are sloping away from our direct vision, and we have entered in a value of 0, which means that these areas will not appear to be transparent. 6. However, to make the effect a little easier to observe, let’s quickly add another key to the gradient to allow for a little more trans - parency, so that the transparency will appear stronger for a further few degrees. 193 Figure 9-50 Figure 9-51 Figure 9-52 Chapter 9············································ Part 3 Create a key a little above the bottom key, and then ensure that its Parameter value is 70 and its Value is 100% as well, as in Figure 9-53. This means that the effect of the transpar - ency will remain at 100% for a bit more than it would have without this extra key. This is really just for effect, and is not entirely necessary ordinarily. 7. Okay, now we have set up the transparency channel as we want it. According to the way in which the Fresnel effect works, we understand that the reflection should basically be the exact opposite of the transparency, because the reflection increases as the transparency decreases. So all we need to do now to set up the reflection proper- ties is to copy this gradient and paste it into the Reflection channel. Once you have done this, simply press the Invert Keys button to invert the gradient. What this does now is give you the exact counterpart of the transparency channel’s gradient. The reflection and transparency values of this surface should now be creating the Fresnel effect perfectly, as the gradients are now creating the effect of decreasing trans - parency toward the edges of the object, while the reflection gradient is increasing the reflec - tion value at the edges. 8. We need to make one more setting to this surface before it is ready to be rendered. Go to the Advanced tab in the Surface Editor. You see the setting called Color Highlights? Change its value to 50%. This is handy for preventing an overblown look on the glass when it is rendered, which is a common problem when making glass. 194 Figure 9-53 Figure 9-54 Figure 9-55 ············································Gradients Creating Textures 9. Now we are ready to render! Ensure that you have activated all your necessary ray-tracing options (Shadows, Reflection, Refraction) in your Rendering Options to ensure that it renders correctly. You can set the Ray Recursion Limit to 8 to save on rendering time. 10. Hit the render button! To improve the chunkiness of the logo when it renders and give it a smoother glass look, you can change the Render SubPatch Level in the Object Properties dialog to a higher value to increase its smoothness when rendered. When you render, your logo should look like Figure 9-58. Notice how the Fresnel effect can be observed in the glass. The reflection becomes much stronger as the surface slopes away from your direct vision. If we had not used the gradients to create the Fresnel effect on the surface, the glass would have looked like it does in Figure 9-59. As you can see, it is a rather big differ - ence! Render the logo from a few different angles and see how the effect works. As I am sure you will agree, this effect is great for added believability in reflective objects, as its behavior is much more realistic. Remember to incorporate this effect into all your reflec - tive objects! 195 Figure 9-56 Figure 9-57 Figure 9-58 Figure 9-59 Chapter 10 Using Weight Maps for Texturing Using Weight Maps to Control the Input and Placement of Gradients and Textures Did you know that weight maps have another use apart from their role in preparing models for rigging? Indeed they do! You can use weight maps in conjunction with gradients to easily control the visibility and placement of colors and textures on your model, which, needless to say, is extraordinarily useful! This can be especially handy when working with procedural textures, since they can otherwise be pretty darn tricky to control. All you need to do is create a weight map, a really simple process, and then use it as an input parameter for a gradient layer in your surface. You then set this layer up as an alpha layer to control the texture layers that you need to. Easy stuff. Take a look at this guy (you may recognize him from a texturing con - test that NewTek ran in 2003). All the details that you see on this guy’s face and head were cre - ated using a combination of procedural textures and gradients that are using weight maps. Some of the gradients are used solely to cre - ate differences in color, such as to create the subtle changes in skin tone and that little white streak on his forehead, while some of the gradients are used to control the visibility of procedural textures, such as seen on the hair bits. Figure 10-1 196 ·································Using Weight Maps for Texturing Creating Textures For this example, I created a num - ber of different weight maps for each of the different details. Figure 10-2 shows the weight map that I created for placing the hair procedurals. This weight map, used as an input parameter for a gradient, was then used as an alpha layer over the proce - dural layer that I used to create the hair look. So how do weight maps work? Well, you simply paint val - ues onto your model, the orangey areas being strong positive values and the blue areas being negative values. The entire range of positive and negative values influ- ences the gradient that they are set up with. Figure 10-3 shows the gradient set up with the previously shown and mentioned painted weight map. As you can see, this gra- dient is acting as an alpha layer (note the Blending Mode) for the procedural texture below it, which cre - ates the hair texture. This particular model had quite a few different weight maps made for it for plac - ing all the procedurals that you see in this image, as well as for placing simple colors. Figure 10-4 shows the weight map and gradient used to cre - ate the white markings on the character’s face. As you can see, this gradient simply creates color at certain weight values. 197 Figure 10-2 Figure 10-3 [...]... television, film, CD-ROM, or larger formats like IMAX Some common broadcast and film resolution sizes are as follows: Broadcast resolutions: D1 PAL D1 NTSC 720 x 57 6 720 x 480 Film resolutions: Cineon Half Film (2K) Cineon Full 2 08 182 8 x 1332 20 48 x 153 6 3 656 x 2664 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Image Maps Creating Textures Now that you know your final output... top of the gradient layer Set the Pro- Figure 10-22 cedural Type to Veins and set it up as follows: Set the Color to 255 , 255 , 255 Set Coverage to 0.02 and leave the Ledge Level and Ledge Width as they are Go to the Scale tab and set the size to 10 mm, 10 mm, 10 mm (See Figure 10-23.) 2 05 Chapter 10 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Part 3 11 The procedural... at –100% (at the top of the gradient) and set its color up as 240, 255 , 15 This creates a yellow color Now select the key at 0% (in the middle of the gradient) and set it up as 230, 50 , 25 Your gradient should now be a yellow fading into a red at 0% Select the key at 100% (at the bottom of the gradient) and set up its colors as 70, 50 , 160 Your gradient should now look like Figure 10-22 Figure 10-21... entire texturing process Figure 11-4 212 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Image Maps Creating Textures You can use any paint software to paint textures, from 2D painting programs like Adobe Photoshop or CorelPHOTO-PAINT (among many others) to 3D painting packages such as Right Hemisphere’s Deep Paint 3D, Maxon’s BodyPaint 3D, Pixologic’s ZBrush (a full 3D. .. photographs or textures baked directly from LightWave (using the Surface Baker shader, described in Chapter 5 as a starting point) or using a combination of all of these The methods you use can depend entirely on the project at hand, the type of texture you need to create, and the amount of time that you have at your disposal to complete the work Some people are texturing purists who like to paint everything... found under Filters>Other>Offset You can use this filter to shift your image so that the edges move inward If I shift the image 50 0 pixels to the right and 50 0 pixels down, using the Wrap Around option, the edges shift to the side and down as shown in Figure 11-16 Figure 11-16 2 18 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Image Maps Creating Textures I can now... applied as a new texture layer above the brown wall texture in the Texture Editor for the color attribute in LightWave) , we can see that the areas not included in the alpha channel are ignored by LightWave Remember to make sure that the alpha Figure 11-20 channel is enabled in the Image Editor in LightWave in order for it to work properly This is a simple example showing a simple alpha channel, but remember... a blank canvas You can then paint areas that increase the value and these areas become a reddish-orange, while decreasing the value results in blue areas 1 98 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Using Weight Maps for Texturing Creating Textures Use the Airbrush tool under the Weight & Color heading on your Map tab to interactively paint your weight map You can open its options... create a key at 100% in the gradient, and set its Figure 10-10 color to white, as shown in Figure 10-10 And if I then wanted to make all the areas that have weight values of 25% blue, then I would just create another key at 25% and set its color to blue If I were using this gradient as an alpha layer for a procedural texture, I would create the procedural texture and set it up as I wish, and then create... to Alpha This gradient will now show the Veins procedural only on the tail part of the spiral to which we assigned a weight value of 100% Figure 10- 25 Figure 10-26 206 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Using Weight Maps for Texturing Creating Textures Render the image Your render should look like Figure 10-27 Figure 10-27 Of course, this tutorial demonstrates a very simple . incorporate this effect into all your reflec - tive objects! 1 95 Figure 9 -56 Figure 9 -57 Figure 9- 58 Figure 9 -59 Chapter 10 Using Weight Maps for Texturing Using Weight Maps to Control the Input and Placement. Color to 255 , 255 , 255 . Set Coverage to 0.02 and leave the Ledge Level and Ledge Width as they are. Go to the Scale tab and set the size to 10 mm, 10 mm, 10 mm. (See Figure 10-23.) 2 05 Figure. nice medium green with the following RGB values: 35, 80 , 25. Set up the actual texture as follows: Frequencies: 5 Contrast: 90% Small Power: 1.0 188 Figure 9-40 Figure 9-41 ············································Gradients Creating