LightWave 3D 8 1001 Tips & Tricks phần 7 pdf

Versions: 6-8 853 Jonny Gorden | Deformations>Morphing and Endomorphs | Beginner Bones in Larger Scenes In larger scenes, make sure the object you’re performing morph animation on is sel

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832 Kevin Phillips | Character Animation | Beginner

Swing Your Head Turns

Next time you animate a head turning from one side to another by simplyrotating it left or right, consider doing this to make the head turn a little morenatural and interesting:

Scrub the frame slider to halfway between the head turn keyframes Rotatethe head down on its pitch slightly and create a key The extra key where the

head dips slightly downward will add a subtle amount of swing to the head as it

turns, giving it a more natural feel

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ÜNote: Unless your character is cautiously turning its head in fear, don’t turn a character’s head too

slowly Consider using between four (fast) to ten (slow) frames as a good basis for a turn of the head

ÜNote: Don’t forget that when we turn our heads, we often subconsciously blink

833 Kevin Phillips | Character Animation | Beginner

Body First, Lip Sync Last

Lip sync is regarded almost as a secondary motion to character animation.You should strive to animate the character’s body language to match your dialogbefore adding your lip sync If your character animation doesn’t feel like itworks without seeing the mouth movement, you should review your animation

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834 Larry Shultz | Character Animation | Intermediate to Advanced

Speeding Up Lip Sync

Sometimes when doing lip sync things can appear to slow down or the audiobecomes choppy Here are a few tips I use to help things along:

n Have Play at Exact Rate checked

n Resample the audio down to the lowest rate possible that is still intelligible

n Lower the SubPatch level on the characters

n Do the lip sync for each character in its own scenes and load them into themain scene later

n Cut off the head, animate the lip sync, and then paste the head back onto thebody later

n Render out preview anims that include the audio in the finished movie file

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835 Larry Shultz, Jennifer Hachigian | Character Animation | Intermediate to Advanced

Crowd Scenes

When animating scenes with multiple characters, things inevitably begin toslow down This happens for a variety of reasons, mostly due to LightWave hav-ing to calculate so many bone displacements, IK, expressions, and so forth

A handy thing to do is to animate the first character and run MD_Scan(Object Properties>Deform>Add Displacement>MD_Scan) on it This “bakes”the motions onto each vertex as displacements MD_Plug is used to replay thedisplacements Once this is done the bones can be turned off and left in place.Why? The bones can still be used to parent things to or as reference for otherexpressions Once this is done the next character can be animated and baked.This allows for a large number of characters to be in scene with a lot less slow-down and allows the animation to be viewed in real time

1 Select the hand bone

2 Go to the frame you wish to copy from

3 Hit Enter to create a keyframe, specify the frame you wish to copy to, andselect Current Item and Descendants

Once you have a couple of poses created, this is a very fast way to block outthe finger animation You can then go through a second pass to refine the fingerposes

Create two versions of the object that will be picked up Parent one version

to a bone in the character’s hand and apply Object Dissolve to it set at 100% solved The second version of the object will be sitting out where the charactercan pick it up

dis-When the character reaches for the second version of the object, dissolve inthe version in his hand and dissolve out the version sitting out Do this over asingle frame and you’ll never see our digital sleight of hand

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Character Animation

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838 Timothy “Amadhi” Albee | Character Animation | All Levels

Reparenting

Say you want to reparent a character’s hand to her hip for an animation ofMae West Go to your character’s setup pose frame (I like to keyframe my setuppose at –200) and with Parent In Place active, reparent that bone (You’ll seeyour mesh instantly and incorrectly deform as it compensates for the “move-ment” affected by the Parent in Place calculations.) Just press “r” to rerecord therest position for that bone after it has been reparented and your model will againreflect its setup pose Go back to frame 0 and start your animation

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Deformations

839 Rob Powers | Deformations | Intermediate

Display SubPatch Level

When working with SubD objects in Layout a Display SubPatch Level of 0will dramatically speed up interaction by preventing LightWave from constantlyupdating the mesh no matter what the object subdivision order setting is Thedownside is that many SubD objects look very poor with a SubPatch level of 0

SubPatch mode to polygon mode with the Tab key As long as you keep theRender SubPatch Level set to a higher number, the object will still rendersmooth

Versions: 7-8

Deformations

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841 Rob Powers | Deformations | Intermediate

Use MD_Scan and MD_Plug

The MD_Scan and MD_Plug displacement plug-ins are hidden gems in theLightWave toolkit that most people overlook They can be used in many differ-ent ways, but two of their best uses are for scenes with groups of characters orcrowds and for speeding up the render process on complex rigs once the finalanimation is completed The MD_Scan displacement plug-in essentially scansthe object on a point level and records the location of each point over time into adisplacement mdd file The payoff is that you can be deforming your objectwith bones, endomorphs, or a complex rig, and the MD_Scan plug-in will

“bake” everything down to one mdd file

You then use the MD_Plug displacement plug-in to apply this recorded mddmotion file to the object With MD_Plug you can control the action start point,the replay speed, the end behavior, and more You can also apply multipleinstances of MD_Plug if you apply the Composite setting in the End Behaviordrop-down You can even transform, scale, and rotate the object with the MD_Plug applied if you set the Key-Move mode to ON If the mdd file that youapply is fairly large, there will be a pause as the scene loads into Layout or on arender farm network; however, after it loads, rendering will be much faster than

if the object was being deformed by bones or a complex character rig To try thisout, simply select your object and choose MD_Scan from the Properties>Deform>Add Displacement menu Double-click on MD_Scan to open the Set-tings panel, and set the location to save your mdd file Then click the OKbutton

You’ll see an “MD_Scan Start” pop-up; select OK again, and MD_Scan willscan your object’s points and generate the mdd file Double-click on MD_Scanagain to open the Settings panel You’ll now see just a save path for your new.mdd file Click the OK button again, and the mdd file will be saved to yourhard drive Now you can load that object into any scene and select MD_Plugfrom Properties>Deform>Add Displacement Lastly, load the mdd file that wasjust created to apply the motion to your object If the object looks strange andit’s a SubD object, be sure to check the subdivision order

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Deformations>Bones

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ÜNote: Not only does it make it easier to “read” your bones in the viewport, it also helps in the SceneEditor as well.

843 William “Proton” Vaughan | Deformations>Bones | All Levels

Bones Aren’t Just for Characters

Ever try to animate a page in a book turning? I created an animation onceusing morph targets (lots of them) to turn a page in a book Later I learned that itwas much easier (100 times easier) to just throw in a chain of bones The nexttime you have to animate something, give bones a try

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844 Steve Warner | Deformations>Bones | Beginner

Use Weight Maps to Organize Objects

People often think that in order to animate a mechanical object, they mustplace the parts that will move on separate layers This can be frustrating, how-ever, as some mechanical objects contain hundreds of separate parts, makingtheir management in Modeler rather cumbersome If you want to keep all ofyour parts on the same layer, simply create a new weight map in Modeler foreach part you wish to animate Name each weight map for the part it’s assigned

to and give it an initial value of 100% (Step 1 below) Now create a skelegon foreach part The base of the skelegon will act as the pivot point for the part it’sassociated with, so position it accordingly (Steps 2 and 2a) Before leaving Mod-eler, bring up the Skelegon Tree (found in the Setup tab of Modeler 8 or theDetail tab of 7.5) Double-click on the Weight section for each skelegon and

Deformations>Bones

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select its associated weight map (Step 3) Save your object and bring it into out The last step is to create bones from your skelegons by using the ConvertSkelegons tool You can now move, rotate, stretch, and scale individual parts ofyour object by simply affecting the appropriate bones (Step 4) This techniquerequires more setup work in Modeler, but will yield more flexibility to you inthe final animation process.

Lay-Versions: 6-8

845 Larry Shultz | Deformations>Bones | Intermediate

Mixing Bones and Multiple Objects

When applying bones to an object we normally think of multiple bones ciated with a single object We can also have multiple objects that share a singleset of bones It’s also possible to construct a segmented character like a robotthat is composed of many parts parented together in a hierarchy What is some-times useful is to allow each part to have its own set of bones This allows forgreater flexibility, especially with characters that may have to have rigid partsmixed with bendy parts This also allows the use of additional objects that areonly affected by particular bones without resorting to weight maps

ÜNote: Falloff Type only comes into use when bones are sharing weight maps or there are no weight

maps being used

848 Todd Grimes | Deformations>Bones | Intermediate

Adjust the Skeleton’s Influence As Needed

Open the Bones Properties panel in Layout Each skeletal hierarchy has afalloff set for its individual bone’s influence You can find this in the Bone Prop-erties panel in the drop-down button next to Falloff Type The higher thefalloff’s inverse distance, the more localized each bone’s influence will be Formore flowing boned objects such as curtains you can try a falloff of Inverse

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Deformations>Bones

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Distance ^2, while more intricately boned objects such as characters will use ahigh value of Inverse Distance ^64 or Inverse Distance ^128.

Versions: 6-8

849 Jonny Gorden | Deformations>Bones | Beginner

Adjust Bone Strength

You can adjust the strength of a bone by adjusting its Rest Length if BoneProperties>Multiply by Rest Length is active This is useful for tweaking defor-mations quickly

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850 Peter Thomas | Deformations>Bones | Beginner

Setting Up Bone Influence

Use Spreadsheet to set up bone influence on weight maps Open sheet, change the left upper tab to Bone Properties: Influence, and select thebone weight maps Select the weight map you want the bone to influence

Spread-Versions: 5-7.5

851 Kevin Phillips | Deformations>Bones | Beginner

The Problem with Partial Weight Mapping

Ever had one of those bones that was affecting parts of the model you didn’texpect, so you decided to add a weight map to it to control that one bone? Thenwhen you moved some of the other bones, sometimes your model would appear

to deform really strangely?

The problem is associated with the way that bones work and how weightmaps are used Bones are like small magnets or force fields That is, they dragall the points in the model about, with the strongest influence on points that areclose and less influence on points that get farther and farther away The distance

at which the influence weakens on points is controlled by the bone propertycalled Falloff A setting of Inverse Distance makes the bone influence slowlyfall off, and Inverse Distance ^128 makes the bone influence quickly fall off.When you stick multiple bones into a model, such as the skeleton inside acharacter, the bones work together, each preventing the others from taking toomuch control of the points that are close to them

Now, a weight map is essentially the equivalent of an alpha channel for abone’s influence When a single bone has a weight map applied to it, the influ-ence of the bone on the points surrounding it gets masked out by the weightmap, and it’s possible that points that the bone was originally holding in placewill suddenly be open prey for the other bones to influence instead When theother bones are twisted or contorted, the influence of the bone is no longer there,and the points in question can get deformed in some unfavorable ways!

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The solution: Don’t weight map individual bones unless there’s a good son to If you must weight map one bone, consider creating a weight map for allthe others, even if it’s just a single weight map that influences all the otherpoints in the model.

rea-Versions: 6-7.5c

Deformations>Morphing and Endomorphs

852 Jonny Gorden | Deformations>Morphing and Endomorphs | Beginner

Setting Paths to Linear

Once you’ve done your first morph animation pass, open Graph Editor andset the curves that pass under 0% or over 100% to Linear

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Bones in Larger Scenes

In larger scenes, make sure the object you’re performing morph animation

on is selected The selected object will update much faster than the other objects

in the scene, allowing for more responsive feedback as you’re scrubbing thetimeline

Oscilla-A similar effect can be achieved by using a bone where the jiggling isneeded and applying Oscillator to the proper channels in the bone to create thejiggling effect

Versions: 6-8

855 Kevin Phillips | Deformations>Morphing and Endomorphs | Beginner

When MorphMixer Doesn’t Work

Take care when you create endomorphs on multiple layered objects If alayer doesn’t need to be associated with the morph, don’t select it as a fore-ground layer Any new morphs get associated with all the vertices that are in theforeground selected layer(s) This is a common case, and can create some mildconfusion when using MorphMixer

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Deformations>Morphing and Endomorphs

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When MorphMixer doesn’t appear to work, make sure that you have applied

MorphMixer to the correct layer in your object Most often, users will not

real-ize this and wonder why their morphs do not appear to be updating on-screen

Versions: 6-7.5c

856 Larry Shultz | Deformations>Morphing and Endomorphs | Intermediate to Advanced

Advanced Endomorph Controls

Typically when you think of controlling endomorphs you immediately think

of using MorphMixer (assuming you know what endomorphs and MorphMixerare) Basically MorphMixer allows you to linearly control a variety of morphswith a slider panel

Another way to control endomorphs is to do it via the Normal Displacementplug-in This allows you to control morphs in a more sophisticated fashion usingtextures In the normal displacement panel set Direction to Morphmap Next toMorphmap, select which morph map you want to affect and click on the Texturebutton

With a gradient you can make the morph occur based on the distance to anull You can also do the same by applying a texture to drive the morph but acti-vate it in specific areas by using texture falloff An almost endless variety ofeffects can be done this way

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857 Todd Grimes | Deformations>Morphing and Endomorphs | Intermediate

Creating Keyframes for Sliders

When using the MorphMixer to animate endomorphs in Layout, hold downCtrl+Shift while dragging a slider This will automatically create a keyframe forevery slider in that group

For any other fake morphs you can just copy the first fake morph This willgive you morph sliders that don’t affect the character geometry for use in otherareas

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859 Patrik Beck | Deformations>Morphing and Endomorphs | All Levels

Morph Levels Over 100%

Morph levels greater than 100% will exaggerate the difference between thebase form and the target form

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Morph Levels with Negative Values

Morph levels with negative values will affect the exact opposite of the ference between the base form and the target form This works very well whenyou use morph targets to simulate mechanical motions

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Flying Logo Letters

The popular effect of having the letters of a word spread apart then cometogether as it flies in can be done much more quickly using morphing instead ofbreaking the word down into separate letters Once the word object is created,create a morph target by moving the letters out from the center one at a time.Each letter should be moved twice as much as the one before it By envelopingthe morph from its maximum level down to 0, the letters will move together

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Combine Bone Deformation with Endomorphs

If a character has a collar that is passing through the geometry of his neck incertain poses, you can create an endomorph on the model with the collar altered

a bit wider Then access the endomorph in Layout with the MorphMixer andadjust the collar on the frames where it’s impeding the neck geometry This pro-cess can sometimes be easier than adjusting the rig after animation has alreadybeen done

Versions: 6-8

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Animating Facial Morphs

It can be useful to parent a new camera to the head bone of a character whenanimating the facial morphs This way you always have a view of the face evenafter you’ve animated the body

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Animating Facial Subleties

Endomorphs can be used to animate facial subtleties For example, creating

a flared nostril target can be used for a character breathing heavily through hisnose, or a raised upper lip target can be used to animate the quivering lips of acharacter about to cry Control targets can also be used to create asymmetry inthe face

Versions: 6-8

Exaggerating Facial Endomorphs

Always exaggerate the shapes of facial endomorphs You can use a lesserpercentage of the shape if the fully exaggerated version isn’t necessary In theevent that you do need the fully exaggerated shape and it’s not there to beginwith, you’ll have to adjust that target in Modeler

When animating lip sync:

n Try to allow at least three frames between phoneme extremes to preventpopping between morphs

n Keyframe consonants two to three frames before the sound, resulting inbetter sync with the sound

n Try to hold consonants for at least two frames for maximum readability

n Make sure you hit all the major consonants We often blur phonemesbetween consonants, but if you don’t hit the major consonants your lip syncwill appear floaty

n Watch yourself in a mirror saying the phrase to get a better idea of what nemes you need and where to place them

pho-Versions: 6-8

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868 Kevin Phillips | Deformations>Morphing and Endomorphs | Beginner

Decapitate for Better Lip-Sync Performance

If you are running a low-spec computer but need to load in your audio and

do lip sync, things can go from sluggish to extremely frustrating very quicklywith regard to animating Low-spec’d computers tend to cause no end of prob-lems with audio playback, especially when scrubbing from frame to frame, andget a lot worse when they also have to redraw the OpenGL display with theupdated morph effect

However, lowering the number of polygons that Layout has to handle andoptimizing the display to work a little quicker can vastly improve the perfor-mance of Layout’s handling of both audio and display, making lip syncing a loteasier When complex models are involved, sometimes a little surgery can assist:

1 Load the character you are working on, and then delete all the body

poly-gons Delete everything except the head Save the model as a new file.

2 Load the head model into Layout on its own If it’s SubPatched, then set the

display SubPatch level to 1 (or 0, although 0 may be too low), and make sure

you set the Subdivision order to Last

3 Add in the MorphMixer deformation plug-in, and load your audio via theScene Editor

4 Do all your facial morph animation with this head model only Fewer polygonsmeans fewer for Layout to deal with and performance should improve substan-tially, hopefully enough to get a fairly good quality audio scrub effect

5 Once you’ve completed your animation, select the Save button on theMorphMixer panel This will save all the morphs in your head, the samemorphs that should also be in your full model

6 Clear the scene and load the proper scene file with your full character model.Select the character and open the MorphMixer panel from the Object Prop-erties Deform tab Click the Load button on the MorphMixer panel and loadthe morphs that you saved from the head animation

7 Ta-da! All the facial animation you created earlier is perfectly loaded ontoyour complete character! Render and enjoy!

Versions: 6-8

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870 Rob Powers | Deformations>Displacement | Intermediate

Preserve Your Displacement Settings

Displacement mapping settings are saved with the scene file and not saved inthe object file This is important to remember because you must use the LoadFrom Scene function to import an object into your scene with displacementmapping settings intact You can find the object’s displacement map settings inthe Object Properties panel on the Deform tab Click on the “T” button to add adisplacement map to your object; you can also animate the displacement mapsover time in this panel

Versions: 7-8

871 Patrik Beck | Deformations>Displacement | All Levels

Displacing in Three Dimensions

Many of the displacement textures only displace on a single axis, eitherstraight up and down or to the sides Fractal Noise and Ripples will displaceobjects in all three dimensions

When applying this tool to subdivision models, you should make sure thatthe SubPatch level is fairly high Set Subdivision Order to First on the Geometrytab so that the necessary geometry is created for the displacement to use SettingSubdivision Order to Last will only apply the bump displacement to the low-rescage model This makes bump displacement more suited for static objects such

as tree trunks, landscapes, and brick walls, among others

Versions: 6.5-7.5c

ÜNote: You can save any subdivision models out as frozen, more detailed meshes by selecting the SaveTransformed Object option from the File menu A purely polygon version of the detailed model will work alot faster in Layout than a bump-displaced one that has to calculate the displacement on the object You canalso optimize the model in Modeler if you wish to cut down the number of polygons for even better perfor-mance in Layout

Deformations>Displacement

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873 Patrik Beck | Deformations>Displacement | All Levels

Better Bump Displacement Control

When bump displacement is used in the Object Properties panel, it deformsthe object using the combined bump maps applied to the surface For better con-trol, copy just the bump map texture layers you want to use from the Bump MapSurface Texture Editor and paste them into the Displacement Map Texture Edi-tor of the Object Properties panel The position and scale values can stay thesame, but you may need to tweak the intensity or texture values This gives youmore control over the displacement amplitude, as well as the option of addingenvelopes

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874 Brad Krause | Deformations>Displacement | All Levels

HDRI Files Can Replace DEM Files for Clean Mesh Distortion

You can distort a flat object mesh using a grayscale image file, like whenyou are trying to create a 3D terrain But pixelated artifacts will appear and themesh will spike, and if you take the values much beyond a rather mild level itwill tear

The solution is to use USGS DEM (digital elevation model) files, availablefor free on the web (http://data.geocomm.com/dem/demdownload.html).You need to bring DEM elevation files into LightWave using a plug-in, likeMike Landis’ ElevationModels, which I use on the Mac

You will end up with a folder full of many files None of the files in theunzipped directory are of any use in LightWave except the largest one, whichalways ends with the characters “CEL0.” That is the file to import

But there’s a way to get around the plug-in after you bring the DEM file infor the first time — save the file as an HDR image file!

If you export the DEM/CELO file out of LightWave as a standard 16-bitgrayscale image, you’ll be back where you started, with a spiking and tearingmesh But the LW-exported HDRI file somehow retains enough of the DEMdata that your distorted mesh will remain as clean as if it were distorted by theoriginal DEM file

After exporting the DEM as an HDRI file, just replace the original DEMwith the HDR image file Thereafter you won’t have to wait for a plug-in tointerpret the data, and you won’t have to worry about other LW users not havingthe right plug-in to open your scene

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875 Kevin Phillips | Deformations>Displacement | Beginner

Effectors Don’t Have Good Parents

Let’s pick a common scenario You have an ocean, and you want to use aneffector to add a deformation from a meteor that is flying overhead So you loadyour ocean model, add in a null, and use it as an effector on the ocean Finally,you add in that all-important particle emitter for the smoking meteor Great, it’sall looking like an easier job than you’d expect!

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However, you then decide to parent the effector to the emitter, so that it willmove along in time with the meteor That should be perfect You animate, andyour effector just isn’t affecting any more! Is the effector broken? Maybe themeteor just is too weak to affect the ocean — you know, gravity and all is differ-ent in the 3D world…

No, the issue is that parenting an effector to another object won’t work Youstill need to move the effector object itself for LightWave to track it correctly Itslocation is seen as relevant to its parent object, so if you parented the null to theemitter at 0,0,0, even when the meteor emitter is moving, LightWave constantlysees the effector at 0,0,0

You can, however, bake in the keyframes using the Motion Baker plug-in,found under the effector’s Motion Options panel, then unparent the effector andapply the baked motion

Animated Splash Ripples

If you’ve ever used one of the Ripples procedurals as a displacement texture

to generate repetitive waves on a mesh and wished that there was some way tomake the ripples appear, then fade out to simulate the effect of an object “drop-ping into” the mesh, here’s how!

To make the ripples fade out rather than infinitely appear across the mesh,use the Texture parameter Falloff tab at the bottom of the Texture Editor panel.This allows you to specify a percentage of fade (or falloff) from the texture’scenter, calculated per unit (which is usually 1 meter by default) Also, for ripples

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in particular, change the falloff type to Spherical By default, the falloff type isusually set to Cubic, which generates sharp, square edges to the ripples.

You can control when the splash ripples will appear by enveloping the ity of the ripple texture over time Make Opacity 0% until it is needed, thencreate a key in the envelope that takes the opacity up to 100%, with another keyafter to create a gradual fadeout over as many frames as needed

opac-For an even better splash effect, add in some HyperVoxel particles that nate from the center of the ripple at the time of “impact” as well

1 Create a single strand of grass using a tube or hair guide

2 Apply a weight map from one end to the other, with one end being 0% (top)and the other being 100% (bottom)

3 Clone the hair guide or grass object all over the “ground” object There areseveral free plug-ins that will clone the objects without losing the weightmap Point Clone Plus will lose your weight map

4 Apply a displacement map to your grass in Layout

5 Apply a gradient on top of your displacement map Set the input parameter

to Weight and select your grass weight map Set the blend mode to Alpha.This will allow the displacement map to affect the geometry based on thestrength of the weight map, which means the roots will stick

Versions: 5-8

Faking Fabrics without Motion Designer

If you plan on having continuous moving objects that need some kind ofcloth simulation for, say, flags or other loose materials, consider using a dis-placement map rather than jumping into Motion Designer straight away

By simply setting the displacement texture to a procedural and setting theWorld Coordinates option, the object will appear to deform and flap around likecloth as it moves through the 3D world

Controlling Flapping Fabrics

For more control on a fake piece of fabric, consider painting a weight maponto the object in Modeler to lay out how strongly you want the effect on thatpoint In Layout, set up your fabric model with your displacement map asbefore, then add a Gradient texture layer that uses this weight map into your dis-placement map texture and set it to Alpha blending mode to control the effect onthe object Don’t forget that you are not limited to just one layer of procedural

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noise, and that you can animate the layers individually This can lead to somequite impressive effects with a little work.

Using Inertia to Flap a Flag

You can use the deformation modifier Inertia to quickly animate a flappingflag Weight map any vertices in your flag model that should not be affectedwith a 0% value (i.e., the flagpole and where the flag joins the pole), and set thevertices that need to be affected with 100% (i.e., the flag fabric itself)

Adjust the pivot point of the flag model to be at the pole (or at least the end

of the flag where the pole is), then apply the Inertia plug-in and set a Lag Rate ofabout 0.1 s/m Animate the flag moving about Instant flag!

For a more realistic effect, try adding the Textured Displacement plug-inafter Inertia and applying a procedural controlled by a gradient (using the sameweight map) to add fluttering and deformation to the flag Why another modifierand not the displacement texture, you ask? Simple — Inertia cancels the dis-placement texture, but you can add it back in by reapplying the textures withTextured Displacement after Inertia

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Character Rigging

881 Larry Shultz | Character Rigging | Intermediate to Advanced

Rigging Tips

Here are some things I see that people seem to miss:

n Deformations should be tested and tuned by posing the character in whatwould be considered its most extreme poses

n How bone falloff, strength, multiply by rest length, etc., all work

n LW bones are not real bones; they are really a type of lattice deformer.LightWave bones once activated simply work You don’t have to pin geome-try to them like in XSI or Maya

n Characters are just a skin; they don’t have internal organs Things must be

done to mimic the effect of having bones, guts, sinew, tendons, etc under the

skin

n Polys can only bend at edges If the edge loops (flow) are incorrect, noamount of endomorphs or weight maps will fix bad deformations due to thebad flow

n Bones only pull vertices Once you understand that you can use it to your

advantage Along with the third item above, this is the key to getting gooddeformations with bones

You have to think outside the typical setups you see with bones (which ably work in the most common circumstances) if you want to see good results.Muscle bones are example of a different way to use bones These are typicallysmall bones added into areas and animated when it is desirable to see the effect

prob-of muscles flexing

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Character Rigging

Using inertia for flags can be enhanced with displacement

for a more realistic effect (please refer to Tips 878 and 879

on displacement).

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In more complex situations it’s better to think about how the shoulder is posed to behave and then determine what configuration of bones and settingswill get close Part of this is remembering that we are animating a skin that sits

sup-on top of muscle, bsup-ones, and so forth So instead of having a single upper armbone, I may break that up into two or three smaller bones where each contributes

a small amount of twist to the skin

When the arm rises, the skin simply is pulled along with the bones, so noproblems here The same when the arm bends forward or backward When thearm is raised higher than parallel to the ground, the collar bone, scapula, i.e., theshoulder girdle kicks in to raise the whole shoulder mass Again, not a hugeproblem (it’s just understanding when the arm stops rotating and when the collarbone starts) Most of the problems come into play when you start twistingthings When you twist your shoulder or forearm, most of the twisting of theskin is away from the shoulder, or in the forearms case more toward the wrist.The solution (for me at least) is to separate bones out into functions Again,what can bones do? They can move, rotate, and pull vertices all at the sametime If you separate bones out into only doing one or two of these functions,you start to see some interesting possibilities For example, suppose you want arig that has IK already set up on it and maybe some expressions watching therotations and so on Let’s say you want to reuse that rig in another character.Based on the way most people approach rigging in LW this isn’t easy to do It iseasier to do if you separate two bone functions found in one bone to two sepa-rate bones: rotation and holding (vertices)

You set up the rig so that you have a small bone at a joint that accounts forjust rotating A second bone off that joint is added to hold the geometry Thismeans that each joint has at least two children: the hold bone and the next jointdown the hierarchy

You can delete the hold bones, and the joint bones would still be there with

IK on them as well as any expressions that watch them You can store this rigwith just the joint bones as a template The hold bones can be easily added tothem by using Draw Bones in Layout or by using skelegons The skelegons in acharacter can be just the hold bones They can be converted to bones on top of acharacter’s existing bones and then simply parented to the proper joint It’s cer-tainly faster than redoing IK and expressions every time It also makes it easier

to tune the bones in Layout because you can add or delete the hold bones at willwithout screwing up IK or expressions

We can extend this idea to the twisting problem We can have bones that arejust for holding, only rotating in the heading and pitch orientations The nextbone down is a twist bone that holds but also only rotates in the bank, i.e.,twists

What happens is that the first bone that rotates but doesn’t twist will resist

the twisting of the twist bone The bone strength and rest length (yes, rest length

can be adjusted after bones are active) can be tweaked to get the right balance

(this is done in the posed position) Further tuning can be done by adding a ond child off the bone that rotates only in heading and pitch This bone can

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further resist the twisting effect of the twist bone only locally Remember thatthe twist bone will have children such as the elbow.

This is very simple to do and set up Lots of interesting things can be doneonce you take this idea and run with it

Versions: 5-8

882 Peter Thomas | Character Rigging | Beginner

Rigging Is a Job in Itself

Think of rigging as one job and don’t go off into an animation unless youhave done all you can in the rig This will allow for animating the rig as quickand easy as possible

This includes locking off all the channels, objects, and bones that will not bekeyed on the character including all the channels control by IK, you don’t want

to create keys that aren’t needed when animating This can easily be done withSpreadsheet in LightWave 7.5 or the new Scene Editor in LightWave 8

Go to the preset banks in the upper right of the panel and select Lockedchannels The first thing to do is lock all the scale channels You don’t normallykey scale unless you are doing toon characters Then lock all the bone positionchannels; you most likely won’t need to move bones at all Then lock off all therotation channels controlled by the IK and lock the position channels of anynulls or control objects that you don’t want to move

Create favorites sets for all the control objects and bones in Graph Editorand selection sets in Scene Editor This makes moving keys around a lot easier.See the Buddha example on the CD

Versions: 5-8

883 Timothy “Amadhi” Albee | Character Rigging | Intermediate

Replace with Item

You can make ultra-low-poly versions of your characters to help speed upfeedback while animating if you have a slow system or if you plan on havingmany characters on-screen at once You can use Replace With Item to swap out

your stand-in with your rendering model (See LightWave 3D 8 Character Animation.)

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a dark blue for the central spine bones These are my preferences, but you canuse whatever colors you prefer as long as it makes the rig easy to view in Layoutand remains consistent for each rig.

There are several plug-ins or scripts available online that will allow you to

do a Load from Scene on your rigs and maintain the schematic view setup thatyou worked so hard on One tool I have used with good effect is Load FromScene Plus Unfortunately, if you use Lightwave’s built-in Load from Scene on arig you will find that the schematic view will be lost

Easier Selection of Bones and Objects

Often when you’re working with a character rig you’ll find that small bonescan be difficult to select Here’s an easy way to fix the problem:

Add a null to your scene and position it somewhere that will make it easy toselect Open the Object Properties panel for the null On the Geometry tab, click

on the Add Custom Object drop-down menu and select the Item Shape plug-in.Double-click the plug-in to bring up its properties window and change the Shapesetting to suit your tastes A box usually works well Then change the size andopacity to meet your needs When you’re satisfied with the look of the ItemShape, close its window along with the Object Properties panel From the Util-ities tab on the main interface, select Master Plug-ins and choose ProxyPickfrom the drop-down menu Double-click on the plug-in to activate its settings.For the Proxy Object, select the null you created For the Target Item, choose thebone (or any other object) you’re having trouble selecting Finally, click onApply Label and close the Master Plug-ins window Now when you click on thenull object, Layout will select the target object instead

Keep in mind that you will no longer be able to move the actual null proxyobject If you find that you do need to move it, simply uncheck the ProxyPickplug-in from the Master Plug-ins panel This will enable you to move the null to

a new location When you’re finished, recheck the ProxyPick plug-in and you’ll

be good to go

Versions: 5-8

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887 Jonny Gorden | Character Rigging | All Levels

Weight Map Only

For character rigging you should never need to activate Bone Properties>UseWeight Map Only

Versions: 6-8

888 Jonny Gorden | Character Rigging | Beginner

Record Pivot Rotation

Try not to use Record Pivot Rotation as it can stuff up targeting and othermotion modifiers Contrary to common perception you rarely need a bone to be

at 0,0,0 rest rotation

When you do need a bone at 0,0,0 rest rotation, clone the bone, set it to 0strength, and parent the working bone to that bone This will give you 0,0,0 restrotation without using Record Pivot Rotation

If dealing with a joint that must rotate in more than one direction, figure out

in which direction the joint will have the greatest range and make that directionrotate on its pitch For example, a wrist bends farther palm-up and palm-downthan it does when rotating from side to side Let pitch control the palm-up andpalm-down for the wrist then, in order to take advantage of Joint Compensation

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LightWave It will allow you to interactively adjust the axis of your pitch, ing, and bank channels in Layout for every bone in your rig.

head-Version: 8

892 Larry Shultz | Character Rigging | Advanced

Skelegons — Bank Handles

Skelegons can be easy to draw but there are some gotchas that can causeproblems It’s important in many cases to know and control which axis of a bone

is oriented along the pitch There are several reasons for this One is that boneproperties such as Joint Compensation and muscle flexing work only on thepitch of a bone Another reason is that it’s more or less accepted convention thatthe direction a simple hinge joint works is the pitch orientation LightWave uses

a parent-based coordinate system, which means that the orientation of a parentbone affects the orientation of the child

With skelegons, the plane in which a skelegon and its bank handle lie mine the pitch Since we are using a parent-based coordinate system, this means

deter-that when you adjust the bank handle on a skelegon it is not adjusting the pitch for that skelegon but for its child.

Versions: 6-8

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Adding Bones

You don’t have to make every bone as a skelegon You can add bones to askeleton/rig in Layout

Versions: 6-8

Quick, Perfect IK Targets

To create quick, perfect IK targets, create a null, turn Parent in Place off, andparent the null to the bone that will control IK Now turn Parent in Place on andreparent the null to the main IK mover or scene mover

896 Dave Jerrard | Character Rigging | All Levels

Setting Up Objects with Nulls

When you’re setting up an object that will use nulls for controls, suck as IKgoals or reference objects, make those nulls part of the object file itself By plac-ing a single point in an object layer, you turn that layer into a null object Sincethat null is part of the object itself, it will be difficult to accidentally lose it Thiswill make the object and its controls much more transportable, especially interms of texture reference objects

Versions: 6-7.5

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898 Larry Shultz | Character Rigging | Intermediate

Bones

I find that how the character was modeled has a big effect on how well itdeforms, and no amount of weight mapping or hold bones seems to help much.It’s also very difficult to know what to tweak until you figure out from yourstoryboards what sorts of things the character must be able to do Put him in themost extreme poses you’ll encounter From there you can determine what needs

to be fixed

I would play around with several things (in no particular order) before going

on to weight maps:

n Joint positions affect how geometry is deformed

n Hold bones are faster to add than weight maps (these can also be animatedfor other effects)

n Bone falloff (^64, ^128 give tighter results)

n Adjust rest length after resting bones You can see geometry grabbed or

released as you change this

n Bone strength/multiply by rest length

n Break single bones into two or more bones to distribute twisting This workswell in areas other than just the forearms (shoulders for example)

n Bone orientation People seem to always set up bones to match the waybones are oriented in real people 3D bones are not at all like real bones LWbones are a special case of lattice deformers; you put them in and they work.Orienting bones in creative ways can yield unexpected results Turning somebones off and leaving others on can give interesting results

n If you do go with weight maps, keep them simple

Versions: 5-8

Stop Joint Popping

To stop joints from popping when animating your rig, make sure you drawthe knees and elbows with a bend in them This may mean you have to edit themodel, but a good bend will set the bones’ rest position and help keep the jointsfrom popping and finking around when animating Sometimes you will still getpopping with this method but that is mostly due to feet and hands being inunnatural positions and not animating the shoulders and hips correctly

See the Buddha example on the CD

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901 Timothy “Amadhi” Albee | Character Rigging | All Levels

Avoiding Gimbal Lock

Because of the order in which LightWave records rotations (heading first,then pitch, and then bank), pitch is the control you should adjust last to minimizeproblems with gimbal lock (where bank, as a child of pitch, is aligned with theheading axis when pitch is +/– 90 degrees)

Sometimes you need absolute precision control over an item’s rotation ing animation, and just letting LightWave in-between your keyframes isn’tgiving you the results you want/need The simplest solution to this is called

dur-“nesting,” where you have a hierarchy of nulls or inactive bones controlling ferent, specific rotation axes If you had a spaceship you wanted to tumble in avery specific way after being hit, using this technique you would make the ship

dif-a child of dif-a null object, using the null to move the ship dif-and to rotdif-ate it dif-along onlyheading and bank axes The ship itself would only be animated to rotate alongits pitch and bank axes I find this gives me the highest level of precision controlfor how an item rotates between keyframes without having a separate item foreach rotation axis

Versions: All

Tiêu đề	Character Animation
Tác giả	Kevin Phillips, Larry Shultz, Jennifer Hachigian, Jonny Gorden
Trường học	Not Available
Chuyên ngành	Character Animation
Thể loại	Hướng dẫn
Năm xuất bản	Not Available
Thành phố	Not Available

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Số trang	65
Dung lượng	0,92 MB