Essential LightWave 3D- P11

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Essential LightWave 3D- P11: What you have in your hands is, quite simply, a collection of tools and techniques that many professional LightWave artists use every single day doing what we do in our various fields. The tools and techniques explored in this book are essential to creating the caliber of imagery that you see on film and television and in print and video games.

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Chapter 13 · · · · · · · · · · · · · · · · · · · · · · · Figure 13-16 16. Now, working with the curves that appropriate for a rubberized bumper, define the rubberized bumper and the and copy and paste the bumper onto opening on top of the kayak, select the your assembly layer. curves in the order shown in Figure 13-16. Fill in the Make Spline Patch window with Perpendicular set to 10 Note segments distributed WRT Length Wouldn’t it be nice to be so brilliant that you (for a nice, soft feel to its silhouette) know exactly what every setting does at every turn? I’m pretty far away from that and Parallel set to 5 segments distrib- myself. To get the above settings correct to uted WRT Knots (so the bumper’s match the bumper up with the kayak’s segments will line up perfectly with the opening, just like anyone else, I had to play segments of our kayak’s opening). around with it a bit until I found the right settings. Still, I didn’t trust it just looking 17. The resultant patch may look pretty right. I tested it, copying both patches to a angular as it skirts the rim of the “junk” layer and using Merge Points to see if kayak’s opening, but I’m planning on it fused the two sections together. No one’s perfect. Don’t bust your chops if using this as a sub-patch model, so it’ll you’re not. be fine. (Notice how the segments of the bumper and the opening line up perfectly.) Assign these polys a surface 288
· · · · · · · · · · · · · · S p l i n e M o d e l i n g E xe r c i s e : K a y a k Figure 13-17 Figure 13-18 18. Selecting a few polys from the nose because I like to get the numeric info sections of our kayak and using Select of just how many points were elimi- Connected quickly selects all the polys nated when I merge points manually.) we’ll need to mirror to become its tail. Because our spline cage was created by Mirror those polys across X=0. (You mirroring, our patches should fit per- may merge points if you like. I don’t fectly by mirroring as well. 289
Chapter 13 · · · · · · · · · · · · · · · · · · · · · · · Figure 13-19 19. Mirror the entire kayak across Z=0, and then merge points. Figure 13-20: Our completed kayak, surfaced and viewed as sub-patches! 290
· · · · · · · · · · · · · · S p l i n e M o d e l i n g E xe r c i s e : K a y a k ... That wasn’t so hard, was it? There are weld all your endpoints. (This is a simple many applications where using spline thing, but it still slips by me from time to patches can be pretty nifty. time.) The hardest part about spline modeling There you go. To quote Obi Wan Kenobi, in LightWave is juggling the settings in “You’ve taken your first step into a larger your mind so your patches end up seaming world.” At the time of publication, only an properly. (It’s a little like that children’s estimated 4% of LightWave users said that game of memory — but it’s not cheating if they understood spline patch modeling. You you want to use pencil and paper.) Just can take pride in knowing that you’re actu- know that it may take a couple of tries to ally ahead of the pack! And to solidify your get things to line up. position there, we’re going to exercise your Also, remember that you’ve got to watch knowledge of splines by using them to the distribution of your knots. You can do model a human head. Flip the page and let’s some pretty fancy tricks through creative begin! placement of those little things. Be sure to 291
Chapter 14 Spline Modeling Exercise 2: Modeling a Human Head Splines are a wonderful tool and I hope step is broken down and discussed in detail, you’re beginning to see just how powerful making it easy to follow, even for new they can be. Splines are most often used to users. That said, however, I expect you to model objects with large complex surface have already worked through the previous areas, such as vehicles and aircraft. In this modeling chapters and to have a basic chapter, we’ll be looking at a more esoteric understanding of the spline modeling rules use of splines, namely for the creation of a outlined in Chapter 12. realistic human head model. We’ll get into the actual modeling This chapter will provide a detailed shortly, but first let’s talk about the things explanation of the process. It is a long chap- that make a good head model. ter, but don’t let that intimidate you. Each Figure 14-1: The head model built in this chapter with textures applied. 292
· · · · S p l i n e M o d e l i n g E xe r c i s e 2 : M o d e l i n g a H u m a n H e a d Poly Count and Flow I’ve seen hundreds of head models and doz- harder than a low-poly object. But the quest ens of tutorials showing how to build them. for minimal polygons isn’t just about render There are as many techniques for building a time. It’s much more practical than that. head as there are people building them. But You see, when you sub-patch an object, you regardless of how the head is constructed, are actually interpolating geometry there are two inherent qualities it must pos- between each point in your object. Take a sess in order for it to be “successful.” look at Figure 14-2, which shows two Contrary to what you might think, looking sub-patched objects. good is not one of them. Rather, the most The object on the left is a simple box successful head models are those with a with a single cut running down the center. reasonably low polygon count and an ideal Moving the points at the center of this box polygon flow. creates a smooth arc from one end of the object to the other. This arc is caused by the Poly Count interpolation of geometry that occurs when an object is sub-patched. Now take a look at The best modelers are always striving to the object on the right. It is the same box, create their objects with the fewest number but in this case, there are six more cuts of polygons possible. This isn’t just an running through it. Moving the middle obsessive-compulsive drive. It’s a practical points on this object still results in an inter- quest. The more polygons an object has, polation of geometry; however, since the the longer it will take to render. Even with points on either side of those being moved the most modern processors, a high-poly are now closer together, the arc is tighter sub-patch object will hit the render engine and more pronounced. Understanding this Figure 14-2: Low poly count enables broader changes to your model. 293
Chapter 14 · · · · · · · · · · · · · · · · · · · · · · · Figure 14-3 simple truth is the key to effective subpatch Poly Flow modeling. The more polygons you have in a The other quality that makes a good head given area, the more pronounced the effect model is proper polygon flow. Flow is a diffi- on the movement of points in that area. cult concept to grasp, especially for Take a look at Figure 14-3. Keeping in beginners. In essence, it is the deliberate mind what you saw in Figure 14-2, you can layout of polygons into overlapping bands or imagine what would happen if you moved loops that, when fully realized, mimic the the points on either of these objects. natural flow of muscles under the skin. Undoubtedly, the object on the left would Keep in mind that as you model, you are enable you to make broad changes (similar simulating reality. Whether it’s a wineglass, to the object on the left in Figure 14-2). a sports car, or a human being, you are Small movements to the points on this building a simulation of a real-world object. object would not have a drastic impact on In the case of organic models such as ani- its overall shape. That’s not true for the mals and people, you are simulating the object on the right. Even minor adjust- features that make up their outward appear- ments to this object’s points would result in ance, typically muscle and bone. It is a noticeable change to its form. important, then, to study in great detail the Learning to control the poly count and forms you are attempting to simulate. understanding where and when it’s appro- Amazing character models aren’t created by priate to add more geometry is a skill that accident. The best character modelers are takes time to develop. But suffice it to say those who have a solid grasp of human that as you model, you should strive to keep anatomy. your poly count as low as possible. 294
· · · · S p l i n e M o d e l i n g E xe r c i s e 2 : M o d e l i n g a H u m a n H e a d Figure 14-4: Basic muscle flow of the human head. Figure 14-5: Bad polygon flow (left) compared with good flow (right). 295
Chapter 14 · · · · · · · · · · · · · · · · · · · · · · · Unfortunately, an introduction to anatomy is muscles in a real face, it will be difficult to beyond the scope of this chapter, but I create realistic expressions in a simulated would encourage you to pick up an anatomy face. You will find yourself fighting the book or attend a figure drawing class if you model to get so much as a smirk. It intend to pursue character modeling. And I becomes imperative, then, to build a model would strongly encourage you to visit with great flow. http://www.fineart.sk and http://www.3d.sk. In Chapter 10, we built a head model These two sites offer the most comprehen- using the detail-out approach. The advan- sive set of resources for character modelers tage to the detail-out approach is that it is a that you can find. WYSIWYG process. You have immediate The need for ideal polygon flow doesn’t feedback on the model at each stage of stem from a purist compulsion. Like poly- development. The problem with the gon count, it is a practical requirement. detail-out approach is that poly-by-poly con- Consider this: Character models are rarely struction makes it frustratingly difficult to built to hold a single pose or a solitary facial develop good flow (especially for beginners) expression (like Michelangelo’s sculpture of and it often yields objects with a high poly David). On the contrary, they are built to be count. Spline modeling, however, avoids animated and posed in a variety of fashions. these pitfalls, allowing you to visualize the A real face can make expressions (e.g., flow of your polygons and to selectively smiling or frowning) because of the layout adjust the resolution of each patch for opti- of muscles in the face. Therefore, if your 3D mal poly count. model’s polygons do not mimic the flow of Spline Modeling Pitfalls Spline modeling, while elegant and efficient, specifying your Perpendicular and Parallel is not without its problems. As we’ve seen patch settings to avoid creating polygons in previous chapters, there are rules that that do not line up properly from patch to need to be followed. And even when the patch. And as if all of that weren’t enough, rules are followed, the occasional “Curves the cold hard truth is that some objects are Do Not Cross” error will appear (seemingly not well-suited for spline modeling. These for no reason at all). Moreover, spline mod- drawbacks cause many modelers to steer eling’s greatest strength can also be its clear of splines altogether. But you’re in biggest weakness, especially when dealing luck — I’m going to show you several with organic models. While splines make it tricks to work around these pesky easy to visualize the flow of your polys, you problems. must have a solid understanding of flow in the first place to build them correctly. You also have to be extremely careful when 296
· · · · S p l i n e M o d e l i n g E xe r c i s e 2 : M o d e l i n g a H u m a n H e a d Spline Modeling Tips and Tricks The major pitfalls of spline modeling can be You have to remember which spline you avoided by following these simple tips and selected first in order to establish how the tricks. perpendicular and parallel patches are con- structed. And then you have to ensure that • Tip 1: Use splines for their strengths, the patches line up properly to those around not their weaknesses. It sounds obvious, but you’d be surprised at how many people them. It’s a hassle, but here’s a simple solu- don’t get this. Splines work best as a visual- tion: Use the same patch settings for the ization tool, allowing you to establish the whole object. If you construct your splines overall form of your object quickly and eas- properly (by making sure your patched ily. They do not work well for creating areas are roughly the same size), you can intricate details, but I see people attempting use the same patch settings for your whole this all the time. They build spline cages object. This can save you loads of time and with an incredible amount of detail and frustration down the line. expect to simply patch it and be done. It Keep these simple tricks in your back sounds great in theory, but it rarely works pocket and they will make your spline mod- out in practice. So rather than using splines eling job much easier. as a be-all and end-all, use them for what Now that we’ve covered the basics, they’re good for — namely building the we’re ready to start modeling. Here’s an overall form of your object. Then use the outline of what we’ll be doing: other tools at your disposal to model in the details. 1. First we’ll build the spline cage. I’m going to show you how to construct a • Tip 2: Build quad cages. It’s best to cage with great flow using the tricks build your cage so that every region is outlined above. Once built, this cage bounded by four splines. I call this a quad can be saved and used over and over cage. It consists of splines for the top, bot- again to quickly knock out other head tom, left, and right for each area in your models. cage, both large and small. Building a quad cage is perhaps the most critical component 2. Next, we’ll patch the splines, add a few of spline modeling, and I’ll be teaching you details, and learn how to reduce the more about it as we proceed. number of polygons to obtain an opti- mal poly count. • Tip 3: Use simple patches. One of the 3. Lastly, we’ll construct the remaining most time-consuming aspects of spline modeling is determining the proper Parallel details using tools you’re already famil- and Perpendicular patch settings. Figuring iar with. this out is like some sort of twisted game. Fire up Modeler and let’s get started! 297
Chapter 14 · · · · · · · · · · · · · · · · · · · · · · · Creating the Cage As was the case with the detail-out can easily be divided into four sections (top, approach, it’s helpful (and often necessary) bottom, left, and right), and that provides a to use a reference image when building good starting point for building a quad cage your spline cage. You can find the images (see Tip #2 above). for this chapter on the companion CD under 1. Begin by laying down three points over Images\Chapter14. In the Setup\Chapter 14 the top of the eye in the Back viewport. folder, there is a Backdrop config file. Bring Then, with the points still selected, use up the Display Options window () and the Create | Curves | Make Curve click on the Backdrop tab. From the Pre- | Make Open Curve tool (or press sets pop-up menu, select Load Backdrop + ) to generate your first and load the Spline_Head_Backdrop.cfg spline. Finally, use the Drag tool (or a file. similar tool for moving points) to adjust Once your images are loaded, zoom in on the spline in the Right view. Keep in the eye on the right (which is the charac- mind that the eye bulges out in the ter’s left eye). Oftentimes, finding the best center, so your middle point should place to start a spline cage can be difficult. I stick out farther than the points on chose the eye as a starting point because it either side. Figure 14-6: Load the Spline_Head_Backdrop file that we’ll use as a reference for building the spline cage. 298
· · · · S p l i n e M o d e l i n g E xe r c i s e 2 : M o d e l i n g a H u m a n H e a d Note Note Don’t feel that you have to adhere to my You’ll notice as we proceed that the splines I particular workflow. I find that laying down lay down don’t strictly adhere to the refer- points and then converting them into splines ence image. Remember Tip #1! At this gives me the control that I want, but if stage, we’re only interested in getting the you’re more comfortable using the Sketch, basic form. We’ll be doing plenty of Bezier, or Spline Draw tools, go right ahead. fine-tuning to the model after we patch it. It’s not important how you arrive at the end So do yourself a favor: Don’t waste time try- result so long as you are comfortable with ing to precisely match the reference image. the process used to get there. Focus on the overall form. Getting it close is good enough for now. The actual refining stage comes later. Note Notice that this spline does not extend over The most basic curve consists of a starting point, an ending point, and a control point the top of the entire eye. Rather, it covers somewhere in between. You can build your about 70 to 80% of the total area. This is splines with as many points as you like, but done to ensure that the splines on either keep in mind that the more points you have, the more difficult it will be to adjust the side of the eye are roughly the same size as overall shape of the spline. those on the top and bottom. Remember Tip #3. We want to create patches that are roughly the same size. If they are signifi- Note cantly smaller, the polys created by patching this area will get crammed As we build our splines, many of them will jut up against each another, creating harsh together, resulting in an unpleasant pinch- angles between them. This is nothing to ing effect that’s difficult to remove in the worry about. There’s no need to rebuild your final object. splines. We’ll be fixing these harsh angles after we’ve completely built our cage. Figure 14-7: Create the first spline over the top of the eye. 299
Chapter 14 · · · · · · · · · · · · · · · · · · · · · · · Figure 14-8: Create the second spline along the bottom of the eye. 2. Create three more points in the Back in Step 1. The middle point on this viewport along the bottom of the eye spline should stick out farther than the and press + to convert endpoints but not as much as the mid- them into a spline. Then shape the dle point for the top of the eye. spline in the Right viewport as you did Figure 14-9: The third spline is created by using the two existing points from our other splines and a new point at the outside corner of the eye. 300
· · · · S p l i n e M o d e l i n g E xe r c i s e 2 : M o d e l i n g a H u m a n H e a d Note then the point on the inside bottom Shaping the spline in at least two of the spline. Then create a new spline by three viewports is something you will always pressing + . need to do. From here on out, I’m going to describe the creation of each spline, but I You’ve just completed the outline of the eye will expect you to make the adjustments using four separate splines. Take a moment necessary in each viewport. to spin around in your Perspective view and check for anything that looks out of place. The outline should bulge out at the center 3. Create a single point at the outside cor- and taper in and back on the sides. ner of the eye. Then deselect it. Now Inspecting your splines like this is a habit select the outside point on the top you should get into. Check it from multiple spline, followed by the point you just angles and don’t be afraid to move points created, and finally the outside point on that seem out of place. Oftentimes you’ll the bottom spline. Press + find that the Perspective view will reveal to create a new spline. problems that would be difficult to identify 4. Create a single point at the inside cor- in the orthographic views alone. ner of the eye. Then deselect it. We’re Now that we’ve got an initial outline, it’s going to repeat the procedure in Step 3 time to branch out. for the left (inside) part of the eye. 5. Create three more points over the top Select the point on the inside top of the eyebrow and convert them into a spline, the point you just created, and spline. Figure 14-10: The fourth spline is created in the same manner as the third by using two existing points and a third new point at the inside corner of the eye. 301
Chapter 14 · · · · · · · · · · · · · · · · · · · · · · · Figure 14-11: Create a new spline over the eyebrow. 6. Create three points under the eye 7. Add a new point where the top of the (about the same distance below as the nose and the eyebrow meet. Move it eyebrow spline is above). Then convert back slightly on the Z axis, then dese- these into a spline. The inside point for lect it. Select the inside point from the this spline should rest at the base of eyebrow spline, the point you just cre- the nose and the outside point should ated, and the inside point from the rest on the cheek bone. spline below the eye. Press + Figure 14-12: Create a new spline under the eye. 302
· · · · S p l i n e M o d e l i n g E xe r c i s e 2 : M o d e l i n g a H u m a n H e a d to create a new spline and adjust the outside of the cheekbone spline. its shape as needed. Press + to create a new 8. Add a new point at the outside of the spline. eye behind the eye socket cavity. Dese- As we did before, spin your view around in lect this point, then reselect the point the Perspective viewport to check for any- on the outside of the eyebrow, the new thing that looks out of place. point you just created, and the point on Figure 14-13: Create a new spline running along the inside of the eye. Figure 14-14: Create a new spline along the outside of the eye. 303
Chapter 14 · · · · · · · · · · · · · · · · · · · · · · · We’ve now got two sets of splines radiat- to ensure that the points in your splines are ing out from the eye of our model. The area merged together properly. Figure 14-16 enclosed by these splines forms a loop, shows the results. known as an edge loop. When we patch the Wait a minute. This is just a grid-like splines in this loop, the resulting polys will mesh. We were expecting a nice clean edge follow the basic musculature of the loop. What happened? Well, here’s the prob- orbicularis oculi shown as the dark polys in lem. Even though we built our splines with Figure 14-15. four sides (as described in Tip #2), the outer splines have no way of knowing that they should be bounded by the inner splines. When we patched the outer splines, they generated polys that ran right over the inner splines. That’s definitely not what we want. In order to resolve this, we need to link the outside splines to the inside splines so that we can patch the region between them. Go ahead and undo the spline patch. 9. Add three points in a roughly horizontal Figure 14-15: The orbicularis oculi edge loop. line about the center of the eye. They should mimic the points in the splines above and below them. In other words, Let’s go ahead and patch them now. Select the middle point should stick out far- the splines of the outer loop in a counter- ther than the ones on the left and right. clockwise fashion and press + Deselect these, then select the points . Accept the defaults of 10 Parallel and shown in Figure 14-17 and create a 10 Perpendicular and press OK. If you get a new spline. “Curves Do Not Cross” error, press Figure 14-16: The results of patching the outside splines. 304
· · · · S p l i n e M o d e l i n g E xe r c i s e 2 : M o d e l i n g a H u m a n H e a d Figure 14-17: Create a new spline that runs from the bridge of the nose to the outside edge of the eye. 10. Select the points shown in Figure 14-18 and create a new spline. Figure 14-18: Create a new spline from these existing points. 305
Chapter 14 · · · · · · · · · · · · · · · · · · · · · · · Note good. But we no longer have a quad cage. Technically speaking, you don’t need the That’s bad. It may look like we have a quad points running through the center of the eye cage, but in reality, each area is made up of that you created in Step 9. But like sub- six separate splines. patches, splines are directly affected by the We can resolve this by partitioning our points around them. I had you add these extra points to provide a subtle element of edge loop with a few more splines, and in control to the splines extending out either the process we’ll begin to expand our cage. side of the eye. 11. Zoom out and create a new point in the center of the forehead, just a bit above Let’s take a look at what we’ve got. By the bridge of the nose. Select the adding these two extra splines, we’ve parti- remaining points as shown in Figure tioned off sections of this edge loop. That’s 14-20 and create a new spline. Figure 14-19: It looks like we’ve sectioned our edge loop with four splines, but in reality, each area is made up of six separate splines. Figure 14-20: Expanding the spline cage 306
· · · · S p l i n e M o d e l i n g E xe r c i s e 2 : M o d e l i n g a H u m a n H e a d 12. Create a new point at the center of the 13. In the Right viewport, create two more nose, about the same distance from the points as shown in Figure 14-22. The bridge as the point you created in Step first should be placed in the temple 11. Then create a second point slightly region of the head and the second off to the right and down a bit. This should be placed above and in front of second point will act as a constraint, the ear. Deselect these points, then allowing us to shape the spline better reselect them in the proper (sequen- to fit the nose. Finally, select the tial) order and create a new spline. remaining points shown in Figure 14-21 and create a new spline. Figure 14-21 Figure 14-22 307