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  Mastering 
 3D Studio MAX R3  | 
  
  
  
 
 
  
 
 
  
  
 Chapter 5 
 Organic Modeling 
 Featuring 
  
 -   Understanding Spline-Based Modeling 
 
-   Shaping Bezier Splines 
 
-   Shaping NURBS Curves 
 
-   Modeling with Patches 
 
-   Modeling with Surface Tools 
 
-   Modeling with NURBS 
 
-   Subdivision Surface Modeling with NURMS 
 
        
 This chapter will familiarize you with the three main 
 organic modeling options in 3D Studio MAX: patch modeling, NURBS modeling, 
 and subdivision surface modeling. You will explore the advantages and 
 disadvantages of the different methods and use MAX Surface Tools to create 
 a model. This chapter will describe the different tools and approaches 
 available to each type of model and give you important pointers for successful 
 modeling. 
 Modeling Organic Forms
 When modeling characters and other organic objects, you often need to 
 create smoothly continuous surfaces that can be edited easily. MAX offers 
 three very powerful options for organic modeling: patch modeling, NURBS 
 modeling, and subdivision surface modeling. These correspond to the three 
 types of model outputs mentioned in Chapter 4: patches, NURBS, and meshes. 
 MAX offers extra versatility by allowing you to convert between the different 
 outputs. NURBS and patch models can be converted to polygonal models and 
 then further edited with mesh tools. Meshes can be converted to patches 
 or NURBS and then edited with the corresponding tools and methods. You 
 are free to experiment with whatever works for you.  
 Choosing a 
 Modeling Approach
 Developing a modeling style is personal. What works fabulously well for 
 one person will be a hair-pulling bundle of frustration to another. You 
 may find using loft deformations to be completely intuitive, for example, 
 while your co-worker finds them unreliable and prefers to move each vertex 
 with transform type-in commands.  
 As another example of choosing your approach to your modeling workflow, 
 consider just the number of ways you can access the sub-object selection 
 levels (Vertex, Polygon, and so forth). You can go to the Modify tab of 
 the Command Panel, click the Sub-Object button, and choose the sub-object 
 level you want from the drop-down list. You can also get there by clicking 
 the individual sub-object icons at the top of the Selection rollout. And 
 when you right-click any object in a viewport, the shortcut menu includes 
 the Sub-Object options, allowing you to navigate levels that way. 
 
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  | TIP You can 
 cycle between sub-object levels by pressing the Insert key. 
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 Multiply this example by the many thousands of commands in MAX, and you 
 begin to get an idea of the choices available to you in developing your 
 modeling style. You may like to use shortcut keys, and may assign your 
 own in Customize Ø Preferences. You 
 may use the right-click shortcut menus for almost everything. These, too, 
 can be customized. You may write MAXScripts to streamline your workflow, 
 use the Tabs in the Shelf Area, or make your own toolbars. You may prefer 
 to build a coarse form first and then add detail, or you may build a very 
 detailed nose and then build the rest of your character piece by piece 
 around it. Youll find the methods that work best for you. 
 
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  | NOTE In the 
 exercises in this book, we will sometimes stick to one technique for 
 a while, to keep things simple, and sometimes vary our technique, 
 to better acquaint you with the different methods available. We hope 
 this will help you discover the methods and workflow that best suit 
 you. 
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 One choice you have to make up front is whether you want to use reference 
 images or to model freestyle. This choice can depend upon the nature of 
 the project, too. If you are hired to model a specific jet plane, for 
 example, you will need to acquire accurate orthographic drawings and model 
 from those. In the examples in this chapter, we will use a freer style, 
 since we have no specific constraints and simply want to acquaint ourselves 
 with the various tools and methods.  
 
 
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  Top 5 MAX Concepts 
 Move or Modify?: The Difference Between a Transform and a Modifier 
 What is the difference between a transform and modifier? A simple 
 enough question,certainly, and easy to answer in some cases. Then 
 why ask it? Its a good question because it forces us to consider 
 what we are doing with our geometry. Do you really know what you 
 are doing to your geometry? 
 Well, if you dont, or if you donХt know what we mean by that, 
 consider the following. 
 On the surface, the definition of this topic is self-evident. A 
 transform is the movement of your geometry from one location in 
 world space to another. A modifier is a change to your geometry 
 in object space. What about when you use the Move, Rotate, and Scale 
 transforms to modify a model? Well of course you are in Sub-Object 
 mode, right? You are just moving a couple of vertices around. Maybe 
 you are collapsing a couple of faces or even turning some edges! 
 But by working at the Sub-Object level, you are working at the 
 heart of the math that the engineers at Discreet have calculated 
 for you. And by transforming an object through space, you are multiplying 
 that small amount of math by however many vertices you have in your 
 model. 
 The difference is the order in which they occur. This is critically 
 important! According to the sidebar in Chapter 4, the dataflow tells 
 us that transforms are calculated after the modifier stack. Meaning 
 that, for example, if you have a cylinder with a Bend that moves 
 20 units in the Z axis, it would be calculated like this: The cylinder 
 is drawn in the view-port,the bend is applied, and the move is calculated. 
 Simple, right? But letХs consider a more advanced implication. 
  
 -   1. Create a box that has a length of 200 
 units, and a width and height of 80 units each. 
 
-   2. Rotate the object 45 degrees in the Z 
 axis. Note the bounding box corner markers are still tight around 
 the box, indicating that the bounding box has been transformed(rotated) 
 in world space. 
 
-   3. Now add a Xform modifier to the object. 
 (Xform is short for a transform in object space.) 
 
-   4. Enter Sub-Object mode and rotate the Xform 
 gizmo 45 degrees in the Z axis. 
 
     
 This time notice that box has rotated just like before, but the 
 bounding box has merely expanded to accommodate the rotation. Even 
 though visually the effect is the same, the two are quite different 
 in terms of dataflow.  
 In the first example, the transform happens to the entire box. 
 This means the creation parameters, pivot point, and bounding box 
 information has all been reoriented. In other words, the entire 
 object was transformed in world space. 
 In the second example, the bounding box orientation information 
 is the same, but the box has been reoriented locally, within the 
 stack. In other words, it has been transformed in object space. 
 So when do I use one or the other? That depends; in 
 some situations, only one method is possible. There may be times 
 when you want to correct the orientation of objects in your scene, 
 and the only way to do this is to adjust the transform. On the other 
 hand, if you are doing any file exporting, you must certainly consider 
 using the Xform modifier to transform an object. This is because, 
 in many export formats, world transformations do not export; and 
 even when they do, each 3D program interprets transforms, especially 
 rotation, differently, so the results are unreliable. 
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 © 2000, Frol (selection, 
 edition, publication) 
 
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