Page 3 of 12
Okay, you're gaining confidence in lighting, and rendering with shadows in trueSpace. Now, let's ease back on the pace of these tutorials, and dwell a little bit on the glitzy super-realistic properties of reflective surfaces. In English, you're going to make a reflective chrome ball now.
1.)Open the file you created and saved last, with the smaller sphere in front of the larger one.
2.)With the Pick tool, click on the larger sphere in the scene to highlight it and then right-click on the paint application icon, as shown in figure 23. You'll see panels open in the workspace, all relating to surface properties of the object (the sphere), as you see in figure 24. Except the panels on your screen probably aren't lettered...
3.) Before doing anything, let's get a grasp on what the panels do. At far left is a color space and a tone slider. You use these to define a color for the surface of an object, and this panel operates just like the light color panel you used last week. By the way, a surface color is negated if you ever put a bitmap surface (called an image map) on an object.
4.) Next to the color definition panel, is the Material preview panel. What you see in this panel is what is loaded to apply to an object. Alternately, if you sample a surface (but we won't cover that right now), the Material preview shows what you are going to apply to an object. There are many, many surface properties, and by learning what these controls do in trueSpace, you'll better be able in the future to make plastic objects look like plastic, wooden objects look like George Bush's head and so on.
5.) Next step: The shaders Map panel. What is a shader? A shader is a component property that defines the surface of an object. In the real world, you might say that something is shiny, but rough. In the world of 3D modeling, "rough" has a control, and "shiny" has a control; the mix is called a shader. Callout a is the amount of smoothing applied to a wireframe model; the top is faceted (no smoothing), the middle is normal, and the bottom button is smooth. The reason why we need these controls is because a wireframe model is made up of straight line vectors, so a sphere with few vectors is going to look funky unless you tell trueSpace to smooth vertices on a clunky-looking object. We will not be using these controls this week, and in general, if your model needs smoothing, there are other, better ways I'll discuss in the future for accomplishing this goal. Callout b is the object property column; on top, is a flat shading for an object, in the middle is the plastic button, and on the bottom is the metal button. These buttons are actually shortcuts to defining a surface-the last panel we explore here can control the sub-properties of, for example, the metal preset. We could in fact choose metal for one of the spheres, and then make the sphere have a rougher, less reflective surface. Try doing this in real life...
6.) Callout C is for image mapping, which deserves an article of its own. To oversimplify, James Blinn, the grandfather of synthetic imagery, devised a way to "paste" a bitmap image onto the surface of a 3D object. It's called image mapping. Now, the top button is for simple image mapping: if you want to put a pattern on a ball, you'd create the pattern in something like Photoshop, and then click on the top button, then right-click on the button to call up a directory box where you locate the pattern image (read this last sentence twice...it is totally un-intuitive to have to left and then right-click to set up the pattern map. And THEN, you have to apply it to the selected object, but I'm getting ahead of myself here. The middle button is for bump mapping. James Blinn's invention again—you create areas of grey in an image, save it and then use it in trueSpace to simulate heights and recesses on the surface of an object without having to actually sculpt every nook and cranny onto the surface. We'll get more into bump mapping in the future. The bottom button, the one we'll use this week, is reflection mapping. Now, trueSpace can render reflections into a scene just fine, thank you, but there will be occasions (I'll point them out in a moment) when you want to use an image instead of telling trueSpace to calculate actual reflections within the scene.
7.) Callout D points to all the procedural textures that trueSpace offers. Okay, what's a procedural texture? A procedure is kind of a math recipe that leads the programmer to offer up something that in the context of surfaces in the 3D realm, obviates the need to use an image map. IOW, a procedural texture of granite (the top button below the D callout) produces a granite look applied to a sphere, for example, without the need to paint a faithful replica (or use an actual photo of) real granite. The advantages of using a procedural texture are 2: First, because the granite (marble, or whatever) is rendered from a math formula onto the surface of an object, it can be scaled up or down without the blurring that would take place if you used a bitmap to image map the look. Also, many procedural textures are called "3D textures", because there is continuity across the faces of an object. Huh? Okay, let's suppose you create half a sphere (also called a hemisphere by people brighter than Bouton). If you used a bitmap to make a surface wooden in appearance, the mapping would abruptly change as the bitmap travels across the smooth surface only to hit the end of the hemisphere. It just would—trust me for the moment. But using s 3D procedural texture, the object would have a smooth wood grain transition from the curved to the flat areas on the hemisphere.