Skin ModifierThe Skin modifier is a skeletal deformation tool that lets you deform one object with another object. Mesh, patch, or NURBS objects can be deformed by bones, splines, and other objects.

Envelope Properties groupAbsolute/Relative

This toggle determines how vertex weights are calculated for vertices between inner and outer envelopes.

AbsoluteA vertex must merely fall inside the brown outer envelope to have 100% assignment weight to that particular bone. A vertex falling inside more than one outer envelope will be assigned multiple weights summing to 100% based on where it falls in the gradients of each envelope.

RelativeA vertex falling only within an outer envelope will not receive 100% weighting. A vertex must either fall inside two or more outer envelopes whose gradients sum to 100% or greater or the vertex must fall within a red inner envelope to have 100% weight. Any points within a red inner envelope will be 100% locked to that bone. Vertices falling within multiple inner envelopes will receive weighting distributed over those bones.

Envelope Visibility Determines the visibility of unselected envelopes. Choose a bone in the list and click Envelope Visibility, then choose another bone in the list. The first bone selected remains visible. Use this to work on two or three envelopes.

Falloff Flyouts Choose a falloff curve for the displayed envelopes.Weight falls off in the area between the inner and outer envelope boundaries if envelopes overlap and Absolute is turned on. This setting lets you specify how the falloff is handled:

Falloff Fast OutWeight falls off quickly.

Falloff Slow OutWeight falls off slowly.

Falloff LinearWeight falls off in a linear way.

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Falloff SinualWeight falls off in a sinusoidal way.

Weight Properties groupAbs. Effect

Enter an absolute weight for the selected bone to selected vertices.Choose the Envelope sub-object level, turn on Vertices in the Parameters rollout Select group, select a vertex or vertices, and then use the Abs. Effect spinner to assign weight. Selected vertices move in the viewports as their weight changes.

Rigid Causes selected vertices to be influenced only by one bone, the one with the most influence.

Rigid Handles Causes the handles of selected patch vertices to be influenced by only one bone, the one with the most influence.

Normalize Forces the total weights of each selected vertex to add up to 1.0.

Exclude Selected Verts Adds the currently selected vertices to the exclusion list for the current bone. Any vertices in this exclusion list will not be affected by this bone.

Include Selected Verts Takes the selected vertices out of the exclusion list for the selected bone. The bone can then affect these vertices.

Select Excluded Verts Selects all vertices excluded from the current bone (see Exclude Selected Verts, preceding).

Bake Selected Verts Click to bake the current vertex weights. Baked weights are not affected by envelope changes, only by changes to Abs. Effect or weights in the Weight Table.

Weight Tool Displays the Weight Tool dialog, which offers control tools to help you assign and blend weights on selected vertices.

Weight Table Displays a table for viewing and changing weights for all bones in the skeletal structure. See Weight Table.

Paint Weights Click and drag the cursor over vertices in the viewports to brush on weights for the selected bone.

Painter Options [ellipsis] Opens the Painter Options dialog, where you can set parameters for weight painting.

Paint Blend Weights When on, blends painted values by averaging the weights of neighboring vertices and then applying the average weight based on the brush strength. Default=on.

Mirror Parameters rolloutMirror Mode

Activates Mirror mode, which lets you mirror the envelopes and vertex assignments from one side of the mesh to the other. This mode is available only at the Envelope sub-object level.

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Mirror mode uses the Mirror Plane setting to determine the “left side” and “right side” of the mesh. When you turn on Mirror Mode, the vertices on the left side of the mirror plane turn blue, while the vertices on the right turn green. Vertices that are neither left nor right turn red, including vertices at the mirror plane. If vertices don't change color appropriately, you might have to increase the Mirror Thresh value to expand the range used to determine the left and right sides.If you select vertices or bones, the selected vertices or bones turn yellow, and the corresponding match on the other side of the mesh turns a brighter blue or green. This can help you check for matches.

Mirror Paste Pastes selected envelope and vertex assignments to the opposite side of the body.

Paste Green to Blue Bones Pastes the envelope settings from green bones to blue.

Paste Blue to Green Bones Pastes the envelope settings from blue bones to green.

Paste Green to Blue Verts Pastes the individual vertex assignments from all green vertices to the corresponding blue vertices.

Paste Blue to Green Verts Pastes the individual vertex assignments from all blue vertices to the corresponding green vertices.

Mirror Plane Determines the plane that will be used to determine the left and right sides. The plane appears in the viewport at the mesh's pivot point when you turn on Mirror mode. The selected mesh's local axes are used as the basis for the plane. If several objects are selected, one object's local axes are used. Default=X.TipFor the easiest workflow with mirroring tools for the Skin modifier, set the pivot points for character meshes to align with the World before applying Skin.

Mirror Offset Shifts the mirror plane along the Mirror Plane axis.

Mirror Thresh Sets the relative distance the mirroring tools will look when setting vertices as left or right. If some vertices in the mesh (other than those at the mirror plane) are not colored blue or green when you turn on Mirror mode, increase the Mirror Thresh value to include a larger area of the character. You can also increase this value to compensate for lack of symmetry in asymmetrical models.

Advanced Parameters rolloutAlways Deform

A toggle useful for editing the transformation relationship between bones and the controlled points. This relationship is initially set when Skin is applied. To change the relationship, turn off Always Deform, move the object or the bones, and reactivate. The new transformation relationship is now used.

Ref. Frame Sets the frame where the bones and the mesh are in a reference position.Normally this is frame 0. If frame 0 is the reference frame, start your animation at frame 1 or later . If you need to adjust bones relative to the mesh, move the time slider to frame 0, turn off Always Deform, move the bones into the correct position, and then turn on Always Deform.

Back Transform Vertices

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Allows you to link the mesh to the bone structure. Ordinarily, when you do this, any movement of the bones causes the mesh to move twice as far as it should, because it moves once with the bones and once with the link. Enabling this option prevents the mesh from moving twice under these circumstances.

Rigid Vertices (All) When on, effectively assigns each vertex to the bone whose envelope has the most influence, as though weighted 100% to that bone. Vertices will not have weight distributed over more than one bone and the deformation of the skinned object is rigid. This is mainly used with game engines that do not support weighted point transformation.NoteThis does not change weight values for vertices assigned to multiple bones, so you can return to distributed weight assignments simply by turning off Rigid Vertices (All).

Rigid Patch Handles (All) On a patch model, forces patch handle weights to equal the knots weights.

Bone Affect Limit Limits the number of bones that can affect one vertex.

Reset group

Reset Selected Verts Resets the weight of selected vertices to the envelope defaults. After manually changing vertex weight, use this to reset weights if necessary.

Reset Selected Bone Resets associated vertex weights back to the original weights calculated for the selected bone's envelope.

Reset All Bones Resets all vertex weights back to the original weights calculated for all bone's envelopes.

Save/Load Allows you to save and load the envelope position and shape, as well as the vertex weights. If you load a saved file onto a different system of bones, you can use the Load Envelopes dialog to match the incoming bones to the current bones.

Update on mouse up When on and the mouse button is pressed down, no updates take place. When the mouse button is released, updates occur. This option helps keep workflow moving quickly by avoiding unnecessary updates.

Fast Updates Turns off viewport display of weighted deformation and gizmos and uses rigid deformation when not rendering.

Ignore Bone Scale Turn this option on to leave a skinned mesh unaffected by a scaled bone. Default=off.NoteTo scale a bone's length, you first need to turn off its Freeze Length option on the Object Properties rollout of the Bone Tools floater dialog.

Animatable Envelopes Toggles the possibility of creating keys on all animatable envelope parameters while Auto Key is active. Default=off.NoteThis does not affect keyable track settings.

Weight All Vertices

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When on, forces all vertices that are not under the control of an envelope to be weighted to the bone closest to them. Has no effect on vertices that are manually weighted. Default=on.TipIf you want to revert vertices to their original weight value, click Reset Selected Verts (in the Reset group) or open the Weight Table, and change the Modified weight status (M) of your selected vertices.

Remove Zero Weights Strips a vertex from its weight if it is less than the Remove Zero Limit value. This helps making your skinned model lighter (in games for instance) because less unnecessary data is stored in the geometry. Also accessible from the Weight Table.

Remove Zero Limit Sets the weight threshold that determines if a vertex is stripped of its weight when you click Remove Zero Weights. Default=0.0.

Gizmos rolloutControls in the Gizmos rollout allow you to deform the mesh according to the angle of the joint, and to add gizmos to selected points on the object. The rollout consists of a list box containing all the gizmos for this modifier, a drop-down list of the current types of gizmos, and four buttons (Add, Remove, Copy, and Paste).The workflow for adding a gizmo is to select the vertices that you want to affect, select the bones that will drive the deformation, and then click the Add button.There are three deformers available:

The Joint Angle deformer has a lattice that can deform vertices on the parent and child bones.

The Bulge Angle deformer has a lattice that only works on vertices on the parent bone. The Morph Angle deformer works on vertices of the parent and child bones.

Keep these distinctions in mind when you select vertices to deform. For example, if you want to use the Joint Angle deformer, then select vertices close to the joint that will drive the deformation. If you want the parent bone vertices to deform like a biceps muscle, then select vertices that are only assigned to the parent bone before adding the Bulge Angle deformer. If all the vertices of the parent and child bone must deform, then select all of the vertices and add the Morph Angle deformer.

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Gizmo List Window Lists the current Angle Deformers.The Deformer Parameters rollout changes depending on the type of gizmo selected.

Deformer drop-down list Lists the available deformers.

Add Gizmo Adds the current Gizmo to the selected vertices.To add a gizmo, you must first select the child bone for the joint you want to deform. Then you must select the vertices that you want to deform. You can then add a gizmo. After a gizmo is added, a Deformer Parameters rollout displays that contains gizmo parameters that you can adjust.

Remove Gizmo Remove the selected gizmo from the list.

Copy Gizmo Copy the selected gizmo.

Paste Gizmo Paste the gizmo.The Paste button pastes the current copy buffer into the currently selected gizmo. You can only paste to like gizmos. For instance, you can't paste from a bulge gizmo to a joint gizmo.

Deformer Parameters rolloutThe following parameters are for the Morph Angle deformer. One way to create morph targets, after the morph gizmo is added, is to add an Edit Mesh modifier to the stack above the Skin modifier. Use the vertex controls in the Edit Mesh modifier to shape the geometry. Then go back in the stack to the Skin modifier and click Add From Stack. You can then delete the Edit Mesh modifier. Add From Stack looks at the last modifier in the stack to get the morph target. Note that when you go back down to the Skin modifier, the morph effect is doubled; you can rectify this by deleting or deactivating the Edit Mesh modifier.Joint Field

Displays the type of Deformer and the associated bone.List Window

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Contains the current morph targets and associated bone angles.Naming Field

Select a morph target and rename it in this field.Add from stack

Uses the current state of the stack to get the morph target. Ideally, you have put an Edit Mesh modifier on top of the stack and done your edits before you click Add From Stack.

Add from node Uses another object as your morph target for this angle. This is like a regular morph target, but instead of being driven by a field, it is driven by the joint angle.TipYou can use Snap Shot on the main toolbar to create a new target for morphing.

Delete Deletes the currently selected morph target from the list.

Enable gizmo Toggles the effect of the gizmo.

Joint Angle and Bulge Angle parametersThe following parameters are for the Joint Angle and Bulge Angle deformers. These two deformers are almost identical in the way they operate. The difference is that the Bulge Angle deformer only works on vertices of the parent bone, while the Joint Angle deformer works on vertices on both the child and parent bone.To apply either of these deformers, first select the child link, then select vertices on the mesh, and then apply the deformer. Remember to turn on Vertices in the Parameters rollout Select group before region-selecting vertices in the viewports.Once the deformer is applied, turn on Edit Lattice and move the lattice control points in the viewports to deform the mesh at different bone angles.Name Field

Allows you to change the name of the deformer.Twist

Allows you to spin the gizmo around the mesh to place control points appropriately.Use Bounding Volume

Turn this on if you plan to change the geometry, like increasing segments on a cylinder. If the geometry changes, the mesh will still deform inside the lattice if this is turned on.

Enable Gizmo Toggles the effect of the gizmo on and off.

Edit Lattice Allows you to move the lattice control points in the viewports.

Edit Angle Keys Curves Brings up a curve editor that lets you manipulate the shape of the lattice at a particular angle. This curve is position vs. angle. It will show you the curves of the current selected points. The red curves are X, green curves are Y, and blue curves are Z.

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