LightWave 3D 8 Character Animation phần 3 pot

3. Maximize a Schematic view (by pressing the numeric keypad’s 0 key, which toggles the “maximized view” mode on and off, just as in Modeler) and organize your character into an iconic representation of a human. As in Figure 5.6, I lean toward a classic da Vinci layout, giving the rough impression of the character standing spread eagle, palms up. 90 Chapter 5: Converting, Organizing, and Aligning Figure 5.6. Animation can be pretty hectic. Every bit of organization you can do beforehand helps. With the controls for your character laid out like this, you can quickly choose the control you need without having to scroll through a list. (This illustration is only a suggestion; it is what works best for me. Feel free to innovate and find what works best for you!) 5.3 Aligning the Spine, Pelvis, and Feet Because the skelegon “bank rotation handle” is a little cryptic to understand, sometimes you’ll find that you’ll need to adjust the rota - tion axes of the bones as Layout has created them from Modeler’s skelegons. 1. Select the Root bone. Depending on the viewport in which skelegons were created, bones created from these skelegons can have a +/–90º bank rota - tion to them (even if the bank rotation handle was never touched). This flip-flops what we would think of as heading and bank for the bone, its children, or both! This isn’t a huge problem, and we could easily work around it. But when we’re deeply engrossed in a scene, and the familiar left-right mouse movement that usually means “I’m rotating in heading” instead rotates these few bones in pitch, it can feel like an unnecessary speed bump in the roadway of production. So, here’s how we’re going to fix it. 91 Chapter 5: Converting, Organizing, and Aligning Figure 5.7. Pitch is what we would normally think of in LightWave as the axis to rotate an item forward and backward (around its X-axis). With the way Root is currently oriented, in order to bend the character forward and backward we would have to use heading (represented by the red circle on your screen). 2. Select your character’s mesh (object). 3. Choose Items|Add| Clone ^C and enter 1 for the number of clones. (See Figure 5.8.) 4. In a Schematic window, move this new object to a place where it won’t interfere visually with the original model and its hierarchy. 92 Chapter 5: Converting, Organizing, and Aligning Note: I’ve found the Clone command to work more reliably than the Clone Hierarchy command. Note: Under Display Options|Schematic View, you'll find a check box labeled “Drag Descendants.” When this box is unchecked, each “node” within a Schematic view can be moved independently of all the oth - ers. When this is checked, moving something in a Schematic view also moves all of its children — this is what you’ll want for Step 4. Figure 5.8. Your model will be cloned, along with all its bone structure. 5. With the clone of your model still selected, open the Classic Scene Editor and choose Select|Select All Bones of Cur - rent Object. 6. With all the bones of the cloned model selected, within the Scene Editor select Colors|Color Selected Items|Orange. 93 Chapter 5: Converting, Organizing, and Aligning Figure 5.9. All the bones of the cloned model will be selected. Note: The bones you just colored orange will be guides for us to match as we rotate our model back into alignment. If you notice in the Current Item field that you’ve got an orange bone selected, stop! LightWave only has one level of undo in Layout. Make sure you have the right bone selected before making changes. 7. Select the Root bone of your original mesh. (It should be cyan, not orange.) 94 Chapter 5: Converting, Organizing, and Aligning Figure 5.10. All the bones you have selected will be colored orange. Figure 5.11. Just making sure that the correct bone is selected. 8. Change your tool (what LightWave does when you move the mouse) to Rotate (Modify|Rotate|Rotate y). 9. In the numeric input field, change the entry for bank to 0. 10. Select the Pelvis bone of your original mesh. 11. Make sure you are at Frame 0. 12. Enter 0, 0, 0 for its rotation (heading, pitch, and bank), and then manually rotate it until it lines up with the orange pelvis bone of the cloned mesh. 95 Chapter 5: Converting, Organizing, and Aligning Figure 5.12. The value for bank in my scene was –90. Changing the pivot’s bank to 0 swings my character’s spine and pelvis onto its side. Newbie Note: After getting each of these bones lined up, press Enter twice to create a keyframe for that bone. Even if you have Auto Key Create active, this is a good habit to get into; it reduces the chances of losing precious minutes or hours of work. 13. Repeat step 12 for Spine1, Spine2, and Spine3. 96 Chapter 5: Converting, Organizing, and Aligning Figure 5.13. After you change the rotation values for the pelvis to 0, you should only need to rotate it along its pitch axis to line it up with the orange reference bone. Almost always, copying the old value for heading into pitch aligns the pelvis and spine bones perfectly. Figure 5.14. The spine bones, back in alignment with our orange reference bones. 14. Select RightFoot in your original mesh. 15. Set its bank rotation to 0. 16. Select RightToes (in your original mesh). 97 Chapter 5: Converting, Organizing, and Aligning Figure 5.15. Changing RightFoot’s bank should leave it aligned with its orange reference bone (even though RightToes is now misaligned). Tweak RightFoot’s heading and bank if you need to. 17. Swap the values for heading and pitch, and zero-out the value for bank; RightToes should line up with its orange reference bone. Tweak as needed. 18. Repeat steps 14 to 17 for LeftFoot and LeftToes. 19. Check to see that the Head,*Hand_Trans, and *Hand_Rot bones also have a bank rotation of 0. Adjust them as needed. 20. Save a revision of your scene. 21. Select the cloned object you’ve been using as reference and press - (or click Items|Delete|Clear Selected) to clear it from the scene. 22. Save another revision of your scene. 98 Chapter 5: Converting, Organizing, and Aligning Figure 5.16. RightToes is back on track. (Nothing is parented to the toes, so they don’t have to be exact.) 5.4 Bone Hierarchy We did a lot of hierarchy work in Modeler with skelegons, but there are some hierarchical things that can’t be done with skelegons. Modeler forces child skelegons to be attached to the tip of their par - ent skelegon. Child bones in Layout don’t have to be right at their parent’s tip. We’ll need this kind of relationship for our character’s fingers as they attach to the hand. 99 Chapter 5: Converting, Organizing, and Aligning Figure 5.17. Your character is done with its virtual chiropractic session; be sure to clear the right object! Newbie Note: With Parent in Place active, LightWave calculates the SRT offset required to keep the selected object in the same “worldspace” (an item’s relationship to the LW world vs. its relationship to another item; more on this in Chapter 8), even though it inherits SRT data from its parent item. LightWave does a good job of this, but it can be fooled by complex hier - archies where items have had changes made to their pivot’s rotation (see Section 5.5). So save revisions and always be watchful for errors in these calculations! [...]... bones we’re using as controls so that LightWave s IK can track these bones’ positions (Yes, it’s rather backward, but bear in mind, most everything cool in 3D is a “hack” of some kind or other “Hacking” in this sense is just working within limitations — inane as they may be — to get the result we need Remember, creativity is your greatest asset in doing anything with 3D A problem or a stumbling block is... Aligning 3 Save a revision of your scene! Figure 5. 23 Record rest position Give yourself a healthy pat on the back! You’ve just completed the first half of character setup! In the next chapter, you’ll finally begin to see the power of the setup you’ve been creating as we start to activate IK 106 Chapter 6 Putting IK and IKB to Work Everything is all set to bring the “big guns” of computer animation. .. 5.21 Both settings need to be active in order for Auto Key to record changes in SRT 3 Make sure you are on Frame 0 4 Select the bone named Root 5 Choose Setup|Modify|Orientation|Record Piv Rot to record the Root’s pivot rotation 1 03 Chapter 5: Converting, Organizing, and Aligning Note: In recording pivot rotation, LightWave (in essence) sets the pivot point’s rotation of the current item to its current... children of Root 8 Make RightShoulder and LeftShoulder children of Spine3 Note: RightFoot and LeftFoot remain children of ch_04 9 Make RightKnee and LeftKnee children of Pelvis 10 Make Pelvis a child of Spine1 (Spine1 being a child of Root) 11 Make Head a child of Spine1 Note: These are options you’ll want to keep in the back of your mind for future reference I’ll go through them in Chapter 8 in the section... be terminating (While working at this stage, I find it helpful to hide the mesh.) 3 Repeat step 2 for RightElbow (the parent of RightBicep), LeftElbow (parent of LeftBicep), RightKnee (parent of RightThigh), and LeftKnee (parent of LeftThigh) 1 08 Chapter 6: Putting IK and IKB to Work 6.2 Creating Goal Objects Because LightWave s standard IK doesn’t let you use bones as goals for IK, we have to add... in Place only works when both items’ pivots are free of rotation So save revisions of your scene before making changes in your character s hierarchy Figure 5.20 The schematic of the character s hierarchy up to this point 5.5 Recording Pivot Rotations Now we’re going to tell LightWave to perceive many of the bones’ current directions as if they were 0H, 0P 0B This is a big help , where gimbal lock may... to Work 6 .3 Activating IK Now, we’ve got to activate IK We’ll be telling LightWave which item will be pulling which chain toward which goal object We won’t see the chains move yet; we’ll still have to tell Layout which axes IK should take over on each item to be controlled by IK 1 Select the RightArm_Puller bone 2 Press to bring up the Motion Options panel for this item (See Figure 6.5.) 3 Select... and translation With World selected, LightWave rotates (or moves) the object in alignment with the worldspace coordinates such that Y is always straight up, heading always rotates with respect to the world’s Y-axis, etc With the coordinates set to Parent, LightWave figures movement and rotation with respect to the item’s parent With the coordinates set to Local, LightWave figures rotation and movement... Section 5 .3) Could we do what we talked about in Chapter 2, “swapping” heading and pitch? Yes, we could, but should we? Only if you want to use that bone’s joint compensation and/or muscle flexing Note: Your character s leg should now follow his foot when you move RightFoot Just make sure you’re on some frame other than 0 when you test it, and delete the keyframe if one is automatically created! 1 18 Chapter... to something you know will work 10 Select RightBicep 11 Set IK to control RightBicep’s heading, pitch, and bank (see Figure 6.11) 12 Select RightForearm 13 Set IK to control RightForearm’s heading (see Figure 6.12) 14 Repeat steps 10 to 13 for your character s LeftBicep and LeftForearm 120 Chapter 6: Putting IK and IKB to Work Figure 6.11 Using IK for all three of RightBicep’s axes Figure 6.12 Using . red circle on your screen). 2. Select your character s mesh (object). 3. Choose Items|Add| Clone ^C and enter 1 for the number of clones. (See Figure 5 .8. ) 4. In a Schematic window, move this new. losing precious minutes or hours of work. 13. Repeat step 12 for Spine1, Spine2, and Spine3. 96 Chapter 5: Converting, Organizing, and Aligning Figure 5. 13. After you change the rotation values. bones we’re using as controls so that LightWave s IK can track these bones’ positions. (Yes, it’s rather backward, but bear in mind, most everything cool in 3D is a “hack” of some kind or other.