Modifier - Bones

Double-clicking on the Bones entry will open a fresh window:

Bone Properties Panel

The Bone property panel gives you access to all the settings available for bones in LightWave Layout.

Bone properties can be accessed in two ways:

Select the Bones button at the bottom left corner of Layout and then click the Properties button located in the same corner.

Alternatively use the keyboard shortcuts Shift B to switch to Bone mode and then P for Properties, or visit Object Properties > Modify and double-click the Bones modifier in the stack

Use Bones From Object

This pop up menu allows you to choose a different object whose bones you would like to use to deform your current object.

Clear All bones

As the name suggests, this button will clear all bones from the current object.

Falloff type

Falloff Type uses a mathematical formula to set the falloff strength of a bone’s influence in the current object. An exponent is used (^2, ^4, ^8, ^16) to figure out how quickly the falloff will happen. The larger the number the quicker the influence of the bones will falloff.

Inverse Distance, Inverse Distance ^2, Inverse Distance ^128

Use Morphed Positions

With this enabled, bone deformations will be applied after morphs. This option can adversely affect performance; normally it should be turned off.

Faster Bones

Each vertex will only be affected by the four closest bones in the object. This can increase performance in objects with more than four bones.

Current bone

Shows the currently selected bone. Multiple bone settings can be edited simultaneously.

Bone Active

When checked bone is on (active).

Rest Position

This sets the default base position of the bone, from which its influence is calculated. You can adjust this influence in several ways including distance falloffs, weight maps and so on, listed below. A bone, moved using the Move tool, can be reset to this default base position by selecting Modify > General > Reset.

Rest Rotation

This determines the orientation of a bone at the time it was rested. A bone, rotated with the Rotate tool, can be reset to this default base rotation, by selecting Modify > General > Reset.

Rest Length

This determines the length of a bone at the time it was rested.

Bone Weight Map

Use this pop up menu to select a Weight Map to apply to the current bone. The influence a bone has on an object's points is now limited to within this weight map.

Use Weight Map Only

When this is toggled off, the bone's influence is limited to the weight map, but the Falloff, Ranges, Strength, Multiply Strength by Rest Length, etc.  all affect the bone's influence within that map area. You can, in fact, use the same weight map on multiple bones (for example assign all the bones in one leg the same weight map) and their influences will be mixed in the non-weight map way, but limited to the area of the weight map. This makes setup simpler for some characters.

When Use Weight Map Only is toggled on, the bone's influence is directly controlled by the weight map, and doesn't use other controls such as Strength, detailed below.

Weight Normalization

Use this option to obtain predictable results when using Weight Map Only.

This feature ensures that the total values of several Weight Maps applied to a vertex never exceed 100%. To calculate the amount of influence a bone will have on a particular point we have to know how many Weight Maps are assigned to bones and what their values are. For example, to calculate the amount of influence a bone will have on a vertex we have to know both the total number of Weight Maps on that point, and also their values. Assuming each Weight Map is assigned to a bone, we will conclude that the amount of influence a bone has on that point is derived as follows:

Point A has three weight maps assigned to it named Upp_Arm, Low_Arm and Elbow.

What is the amount of influence the Elbow bone will have on Point A ?

Point A = Elbow/(Upp_Arm + Elbow + Low_Arm)    

Strength

Strength acts as a multiplier on the influence of the bone. 100% means its influence is calculated as normal from its falloff, length etc. 0% will mean it has no influence, like deactivating it. 50% will halve its influence and 200% will double its influence. 

Multiply Strength by Rest Length

The Multiply Strength by Rest Length option (Bones Panel) causes a bone to multiply its Strength by its Rest Length to determine the influence of the bone. Bones with larger rest lengths will exert greater influence over other bones with equal Strength values, but smaller rest lengths.

Limited Range

When Limited Range (Bones Panel) is active, the Min value determines the sharp cutoff point of a bone’s influence. Any points within this range are 100 percent affected by movement or sizing of the bone. Any points outside of this range are affected to a smaller extent or not at all depending on whether they fall within the Max. In an orthogonal view, the Max setting is visible in the viewport.

A short bone will exert a spherical influence, while longer bones exert a more oblong influence.

Bone Displacement/Parent Displacement

These Texture panels allow you to distort your mesh in the bone's (or its parent's) X, Y and Z axes. The amount of the displacement is affected by the influence of the bone on the mesh, so where your bone affects the mesh 100% the displacement will be 100%, and where its influence is 0%, the displacement will be 0%. You can use images or procedurals, but gradients have some special inputs beside the usual ones (distance to pivot etc). These are detailed here.

Joint Compensation

Sometimes bones used to create joints can cause pinching or unwanted bunching, much like a folded garden hose. Joint Compensation (Bones Panel) will remedy this effect by making the affected points tend to maintain the original volume inside the joint. The result is a more realistic-looking joint. You can modify the compensation amount to increase or decrease the effect.

Joint Comp for Parent

This option shears the points affected by the parent bone during the child bone’s rotation. This compensation also alleviates the pinching effect often caused by bones. At the same time the point shear occurs, the bone will also try to maintain the volume inside the joint.

Muscle Flexing / Parental Muscle Flexing

With Muscle Flexing, the points affected by the bone will flare out as the bone is rotated. Parental Muscle Flexing is more commonly used than Muscle Flexing. For example, when your forearm rotates your biceps flex. The forearm is the child and the bicep is the parent. It would not look natural for the forearm to bulge as it is rotated, but it looks perfectly natural when the biceps flex.

Muscle Bulge / Parental Muscle Bulge

These bulge the mesh outwards around the bone/parent bone depending on the angle of the bone (in the case of Z-bones, this is only around the Pitch axis, but for Joints, this is all axes). It can use Textures to control the shape of this displacement like Bone Displacement/Parental Displacement, except this displacement occurs directly away from the bone, not limited to one particular axis. This has the same gradient options as the Bone Displacement/Parental Displacement, but again, these gradients affect the points in directions away from the bone, not just in one axis. For this reason, it will probably be the more used option than just the Bone Displacement/Parental Displacement textures. The effect simulates muscles bulging under the skin. The gradient inputs are discussed here.

Twist

The rotation axis most aligned with the bone at rest is used. For zero-length bones the bank axis is used. The amount of twist is the change in rotation of that axis between rest and current (limitation: local rotation values are used, so a twist of a bone is not inherited by child bones). There is a Twist toggle in the bone panel (default on), and an input which controls how curly it is (0% is no curl, 100% is curl by the amount of twist over the length of the bone).

Bone Icon Size

Changes the size of the bone icon in the OpenGL display. It does not affect how the bone influences the mesh or other bones.