LightWave 3D 8 Character Animation phần 4 docx

14. Enter 50 for Value 1. (We only need to worry about Value 1 for point weighting; LightWave automatically assumes the value to be a percent.) 15. Select RightCalf as the active weight map. (The red coloring will disappear from the Weight Shade window because only RightThigh has values assigned to its points right now; RightCalf does not.) 140 Chapter 7: Point Weighting Figure 7.6. After pressing Enter in step 14, the surface surrounding the isoparm defined by the points we have selected turns the shade of red corresponding to the value of +50%. 16. Activate Set Map Value again, and enter 50 for Value 1. 17. Select the points that influence the isoparm directly above the knee joint. 141 Chapter 7: Point Weighting Figure 7.7. These points will now move with 50% of their influence coming from RightThigh and 50% coming from RightCalf. Figure 7.8. These will be influenced 25% by RightCalf and 75% by RightThigh. 18. With the RightCalf map still as the active weight map, activate Set Map Value and enter 25 for Value 1. 19. Select RightThigh as the active weight map, and set Value 1 for these points to be 75. 142 Chapter 7: Point Weighting Figure 7.9. RightCalf now has 25% influence over these points. Figure 7.10. RightThigh now has 75% influence over these points. 20. Select the points that influence the next higher isoparm. 143 Chapter 7: Point Weighting Figure 7.11. These points will be set to follow RightThigh 100%. 21. Bring up Set Map Value again and enter 100 for these points. 22. Set the points of the next highest isoparm to a value of 75 for RightThigh. 144 Chapter 7: Point Weighting Figure 7.12. These points will now follow 100% of RightThigh’s motion. Figure 7.13. These points will move 75% with RightThigh and 25% with Pelvis. 23. Select the Pelvis weight map (in the lower-right corner), and set Value 1 for these points to 25. 145 Chapter 7: Point Weighting Figure 7.14. These points will now move 25% with Pelvis. Figure 7.15. Set the points of the isoparm just below the knee to move 25% with RightThigh and 75% with RightCalf. (Two images are shown together for illustrative purposes.) 24. Hide the foot so we can be sure to only select the points of the pant leg. 146 Chapter 7: Point Weighting Figure 7.16. Set the points of the next two lower isoparms and the points that make up the top of the foot to move 100% with RightCalf. Figure 7.17. Using this illustration as a guide, assign RightCalf weight maps for these points. Figure 7.18. Using this illustration as a guide, assign RightFoot weight maps for these points. 25. Press \ to unhide everything in the model. 26. Rehide everything except the right foot. This method is the basis for all point weighting. As you gain famil - iarity with this process, you will develop your own ways of working, your own tricks and shortcuts. Where multiple bones exert multiple influences, such as in the shoulder where a point may be affected by Spine3, RightShoulder, and RightBicep, you simply visualize how much influence each bone should have on the point and assign the values accordingly. 147 Chapter 7: Point Weighting Figure 7.19. Using this illustration as a guide, assign RightFoot weight maps for these points. Figure 7.20. Using this illustration as a guide, assign RightToes weight maps for these points. The values on each point must add up to 100%. If the combined values on a point add up to less than 100%, it will get “left behind” as you move the model. (The closer to 100% this cumulative value is, the less noticeable the lag, until the character is moved signifi - cantly from its starting position. Be very watchful of these values.) If you have the combined values on a given point add up to more than 100%, that point may “leap ahead” of the motion described by its controlling bone. (LightWave has a bit of a fix for values over 100%: activating Weight Normalization under the Bone Properties panel of Layout. It is far better to be precise with your point weight - ing than to depend on software to fix it though.) 7.3 Swapping Models and Testing Weight Mappings The only way to really know if your point weighting is working is to take it for a test spin in Layout. In this section, we’ll check out the weighting we just did for the right leg. To do that, we’ve got to swap out an old model for a new one. Using this technique, and having common bone and weight map names, you’ll be able to use almost every animation you do with almost every character you make! 148 Chapter 7: Point Weighting Note: Figure 7.21. LW[8] has a new Setup|Skelegons|Rotate Skelegons tool that lets you test your weight mapping right in Modeler. This is exceptionally handy for tweaking problem areas. However, putting your character onto his fully functional rigging is the only way to truly know how his “skin” will behave under animation conditions. 1. In Layout, load up the scene you created in the last chapter. 2. In a working directory set aside for Chapter 7, save a version of this scene with a name that will make sense to you if you come back to it years later. Something like “Scenes\Work\ ch07\ch_07_MappingTest_01_v001.lws” will do nicely. 3. In the Classic Scene Editor, make sure that your character model’s visibility is set to at least Shaded Solid. 4. Press <f>, and type 10 to jump to Frame 10. (We’re going to be playing with the controls on Frame 10, so we can check that our character comes in properly on its “rest pose,” Frame 0.) 149 Chapter 7: Point Weighting Note: If, while you’re working, bending your model around, you accidentally hit <r> (an easy thing to do), LW will record the selected bone’s current position and rotation as its rest posi- tion. If this happens, your model’s skin will be fouled for that bone. To fix it, you need to go to the frame where the skeleton is at rest and press <r> for the offending bone. So, once again, just to drive a point well into the ground: You always need to have a frame in your scene where your skeleton is at rest. This can be at 0, –20, –100, or whatever. Just don’t get caught putting the final touches on your masterwork scene (which, because of being “in the groove,” wasn’t saved for several hours) and accidentally tap the <r> key; otherwise you’ll likely wind up exploring new and more creative combi - nations of expletives than you ever thought possible. Note: If you need to use mine, it can be found in Scenes\chapters\ ch_06.lws. [...]... gimbal lock makes things tedious 8. 2 Root The Root bone will move everything but your character s feet (See Figure 8. 2.) You can use this bone to get general upper carriage movements while your character s feet stay rooted firmly to the “floor.” Figure 8. 2 Moving Root in –Y, you get the character s upper carriage to move downward The character s feet stay locked in place 4 Root is designed to move and... pose Figure 8. 3 Rotating the Pelvis bone along its heading axis 4 Pelvis is designed only to be rotated It may be rotated in all axes 172 Chapter 8: Using the Controls 8. 4 Spinal Bones The bones of the spine do pretty much what you’d expect; they rotate to curve the spine of the character into the shapes you need Spine1 does double-duty, however, in that it also is used to position the character, leaving... his hands and feet won’t move until you move them with their separate controls.) Figure 8. 4 Moving Spine1 in –Y lowers the character, but his hands and feet stay where they are 173 Chapter 8: Using the Controls Figure 8. 5 Rotating Spine1, Spine2, and Spine3 in heading 4 Spine1 may be rotated and moved on all axes 4 Spine2 and Spine3 may be rotated on all axes Note: Head is a child of Spine1; it will... Scenes\chapters\ch_07_PoseTest.lws is a series of poses to see how your character s skin stretches when in common and extreme poses 4 Scenes\chapters\ch_07_MotionTest.lws is a short animation for you to see how your character s skin stretches as it moves through a quick bit of action Note: In the following chapters, I’ll go over the animation controls, and you’ll be putting your character through a series of poses If, as you... animator for the character or the animation director do a little animation for the character so the motion technical directors (the guys in charge of skinning and a great deal of other things as well) can scrub through the animation frame by frame to see if and where their point weighting could be improved To this effect, there are two scenes that you can load and swap your model into: 4 Scenes\chapters\ch_07_PoseTest.lws... moving the character to where he was going to start his scene I gave this up because it is just one more thing to build, one more thing to keep track of I now just use the model itself for the gross positioning control Figure 8. 1 Using the model itself (Objects\Final\Thinguy_F.lwo in my case) to orient and position the character to where he will start his scene 170 Chapter 8: Using the Controls 4 The model... Tab to convert subpatches into polygons Figure 7.30 The character s mesh, in polygons 4 Switch back to Layout With the Hub active, you should now be looking at your scene with your character as a polygonal mesh instead of subpatches If this doesn’t happen, you may have to save the object in Modeler, then reload in Layout to update the changes 1 58 Chapter 7: Point Weighting Note: If Layout and Modeler... familiar to start all your animations 167 Chapter 7: Point Weighting And that’s it! These are the secrets to character setup (or at least some of them) Everyone has their own way of doing things; everyone finds ways that work best for them You can use this information as is, or you can blend and mold it to fit your specific needs Hopefully, even if you’re new to LightWave and/or character setup, this section... computer animation Computer animation is in a constant state of evolution New riggings are constantly being devised, revised, and abandoned, evolved upon, and stripped down If you happen to stumble upon (or forge through sheer effort) something great, share it with others You’ll be helping the world of animation as a whole, and bettering the impression of animators and technical directors in general! 1 68. .. with driving this character with standard IK The last section will show you how to use the IK Booster settings we brought to bear in Chapter 6 Newbie Note: If you would like to work from my setup, it can be found in Scenes\CharacterSetups\Thinguy_Setup.lws on the companion CD 169 Chapter 8: Using the Controls Note: If things do not work as described, there may be problems with the character s hierarchy . names, you’ll be able to use almost every animation you do with almost every character you make! 1 48 Chapter 7: Point Weighting Note: Figure 7.21. LW [8] has a new Setup|Skelegons|Rotate Skelegons. convert skelegons into bones, and you have already created weight maps (which we did in Chapter 4, Section 4. 6, Step 24) , bone weight maps are automatically assigned to the bone (skelegon) of the same name model’s points. 7 .4 The Use Weight Map Only Option There are many and differing views on whether or not to let LightWave s mathematical falloff for bones play a part in skinning. Letting LightWave use