Skin Atelier


The Skin Atelier is meant to manage skinning weights, meaning by that: Bind, Edit and Mirror your skinning weights.

This window is divided in 2 different parts:

  • The upper part concerns the Duo Skin features (Bind Skin, Auto Smooth) as well as Mirror Skin, Copy Skin and few other features
  • The down part concerns the Skin Numerical Field Editing

Let's start with the middle part!


Duo Skin and other skin features

The Duo Skin process is our new automatic skin workflow developed to provide (far) better and quicker results. 

This process is called « Duo Skin » as it is split in 2 different steps:

  • During the 1st step Akeytsu will bind in rigid your mesh(es) to your skeleton
  • Then (2nd step), Akeytsu will perform smoothing over 1st step influences

How to use it ?

  1. First of all, use Ctrl+Left Click to gather both desired mesh(es) + desired joint(s). To select the character, go in the Tree window, to select joint(s), it's often easier to parse the picker window (instead of expanding the whole tree hierarchy),
  2.  hit the Bind Skin command. It will (pre)bind in rigid your selected mesh(es) to your selected joints and then automatically perform a smoothing straight afterwards. From that moment, you already get your smoothed skin.
  3. If you are pleased with the result you can stop here!
  4. If you want to adjust your skinning, you have got two solutions:
    1. Easy & Quick: go back into the Rigid step (by using the Duo Skin Mode button), manually refine your rigid skinning zones (using rigid tools only) and hit the Process Smooth Skin button to perform a new auto-smooth pass.You can then iterate the process on the full skinning or on specific parts as well as setup each joint smoothing strength in front of each one in the Picker window
    2. Longer: stay into the Smooth step and manually refine your smooth skinning zones (using smooth tools)

Now discover the features more in details!



 Bind Skin: Bind in rigid the selected meshes to the selected joints and auto-smooth the whole influences straight forward.

 Process Smooth Skin: Generate smooth (end) skin from rigid (start) skin according to your joint selection (and potentially vertex selection) as well as the smooth factors displayed into the Picker (once the skin is pre-bound). 


Duo Skin Mode: Display and edit either rigid (start) or smooth (end) skin. 

Unbind Skin: Unbind the current skinning, meaning that your skinned mesh(es) return(s) to mesh(es) state. By the way, another method to unbind your skinning is to drag'n'drop your skinned mesh(es) outside the Character node into the Tree window. 

Hide Skinned Mesh Vertices: Hide the faces corresponding to the selected vertices. Very useful to skin from the inside of the model or to hide the empty side when you work on your half skinning.

Mirror Skin Weights & Joints: Mirror the skinning weights and the joints in same time. Please notice that the mirroring process works according the YZ plane and the (side) joints must have the following tags in their names : r_/l_/R_/L_ as prefix, or _r/_l/_R/_L as suffix or even right/left/Right/Left anywhere in the name. Then select the side you want to mirror and hit the command. If the joints already exist on the other side, only weights will be mirrored. 



Update Skinned Mesh: Allows you to quickly replace the existing skinned mesh by an unbound (new) one. The tool will smartly transfer all weights to the new model and remove the old mesh. If you want to keep your old mesh, you need to duplicate it and select only one of your two copied meshes, then your new un-skinned model and finally execute this command



Copy Weights: Copy weights values of the selected vertices. 


Paste Weights: Paste the previous copied values onto the current selected vertices.

Fix Weights: Average weights on the selected vertices according to neighbour vertices.

Sweep Weights: Clean very small weights on the selected vertices. The threshold is available into the Skin Atelier preferences.


Full Select Mode: If enabled, this mode allows to select front and back vertices using pick/rectangle mode and lasso. By default this mode is disabled, providing a classic paint mode, meaning front vertices only.

Weight Scanner (Shortcut: S): If enabled, the Weights Scanner will display (inside the 2D brush) the weights of the vertex located under the center of the brush.

Weight slider: Weight value applied in different ways depending on the selected paint mode (Add/Remove or Target). You can enable a slider step mode into the Skin Atelier options.

Strength slider: Strength is a factor altering the amount of weight treated by a brush stroke. In Add/Remove case, strength acts as an opacity factor, meaning that if Strength=1 the weight value will be applied while if Strength=0.5 (or .5) weight value's half will be applied. In Target case and for a new influence (initial weight=1), if Weight=1 and Strength=0.5, successive brush stroke results will be 0.5, 0.75, 0.875, etc. In Smooth case, strength defines how much the smoothing is applied. You can enable a slider step mode into the Skin Atelier options.

Size slider (Shortcut: W): Size factor of the paint brush. 

  • You may increase brush size by LMB (or RMB) + drag up (or drag right) + W
  • You may decrease brush size by LMB (or RMB) + drag down (or drag left) + W

Skin Numerical Field Editing

This part of the Skin Atelier allows you to work directly with your vertices, meaning selecting them and entering numerical values and/or using the Weight Ramp.

The following features require, of course, that a vertices selection has been made beforehand.

Pick/Rectangle Vertex Selection:

  • Select vertices: LMB clicking (or rectangular selection) + Shift
  • Add to vertex selection: LMB clicking (or rectangular selection) + Ctrl
  • Remove from vertex selection: LMB clicking (or rectangular selection) + Alt

Lasso Vertex Selection:

  • Select vertices: MMB clicking and dragging + Shift
  • Add to vertex selection: MMB clicking and dragging + Ctrl
  • Remove from vertex selection: MMB clicking and dragging + Alt

Other Vertex Feature:

  • Increase vertex selection region: "+"
  • Decrease vertex selection region: "-"
  • Select all vertices: "*"
  • Invert vertex selection: "/"

 Weight Ramp:

The Weight Ramp allows to quickly add or remove weights on the current influence (or joint)

As for the circular Spinner, you click on the "spinning" area and drag Up to add weight and drag Down to remove weight. Increasing and decreasing speed depends on the step value displayed in the Ramp. You may change this value by double-clicking in it

 

 

Influences & Vertices Editor:

In this compact editor, you may see and edit your unlocked working influences (or joints) as well as edit your vertex weights


Influences:

On the left side you may find the influences you directly selected in the Picker or the 3D Viewport, or the influences you indirectly selected by selecting their vertices. Indeed selecting vertices make their corresponding influences enter directly in the editor. When you select an influence, this one is automatically unlocked and enters the editor while those missing remain locked into the Picker. You may lock/unlock influences only in the editor. The current influence is highlighted in white color and displays the painter icon. Influences are ordered in the same way as in the Picker for consistency. 

Making a RMB click on an influence's name displays an additional menu:

  • Select partner influences: Selects (so unlocks) all the influences sharing weights with the current influence.
  • Select influenced vertices: Selects all the vertices of the current influence.
  • Attach selected vertices: Sets the selected vertices to 1 value for the current influence.
  • Select vertices influenced by all selected influences: Selects (so unlocks) all the influenced vertices of all selected joints


Vertices Editor:

In case of vertex selection, you may find on the right side of the editor three values columns corresponding to vertex weights:

  • The central column displays weight values of the last selected vertex. This column is the only one you may edit (by entering numbers or by using the Weights Ramp).
  • The left column displays the minimum weight values of the vertex selection.
  • The right column displays the maximum weight values of the vertex selection.

Weight Colour Ramp

 0

Skinning colour feedback goes from yellow (1 value/vertex fully affected) to blue (near to 0 value - vertex unaffected). When you select a joint, the displayed colour feedback shows the actual skinning weights representing the joint influence.


Influence Lock Rules & Weight Share Rules

In Akeytsu, our goal is to merge completely our different skinning workflows, meaning the Skin Painter and the Skin Numeric Field Editing. The Skin Atelier design allows to work the same way with or without selected vertices. In this way you are able to paint your weights and select/edit your vertices without slowing down your workflow. To this end we defined some important influence lock rules and weight share rules. Let’s discover akeytsu’s rules.


Influence Lock Rules:

Selecting influences (or joints) automatically unlocks them and locks* the unselected influences. However there is an exception. If you select one and only one influence (without vertex selection) you will notice the unselected ones are exceptionally unlocked. We call it the Free mode.

Selecting vertices automatically unlocks their corresponding influences.

* Lock an influence: weight editing will not affect this influence


Weight Share Rules:

If you add weights, you grab it from unlocked influences in proportion.

If you remove weights,

In case of unlocked new influences only (please note we can only add a new influence per vertex at a time),

If there is only one, this influence is chosen to receive weights.

If there are many ones, akeytsu will choose (per vertex and according to the vertex position) either the father influence or a child influence, to receive weights. It is the case when you remove "1" weight vertices without selecting an other influence to receive weights.  

In case of unlocked new influences and partner influences***, leaving weights return in proportion to partner influences only.

***Partner influence: influence sharing weights with the current influence


Skin Atelier/Painter Preferences

You access the specific preferences of the Skin Atelier by clicking the cogwheel at the top right corner of the window.

[Painter] Weight step: Enable or disable a "step" (or snap") when you move the weight slider. You define this step into the corresponding "Step value" field.

[Painter] Strength step: Enable or disable a "step" (or snap") when you move the strength slider. You define this step into the corresponding "Step value" field.

              Sweep below: Weight value threshold used by the "Sweep Weights" command.

[Painter] Hide 3D manipulators if skin painter turned on: If enabled, this feature will hide the 3D gizmos while skin painting stage.

              Allow to mirror weights on different skinned meshes: If enabled, even if the source point and the target point of the mirror do not belong to the same mesh, the algorithm still mirrors the source point at the target point.

              Max inf.pr vtx: The Duo Skin algorithm and the Skin Painter algorithm will associate at maximum to each vertices the number of joint specified.

              Low smooth strength (recommended for face): Strengh associated to the joint tagged as low in the picker. The strengh modifies the smoothing of the skinning. This is a Duo Skin preference.

              High smooth strength (recommended for body): Strengh associated to the joint tagged as high in the picker. The strengh modifies the smoothing of the skinning. This is a Duo Skin preference.

              Negligible inf: The weight below this value will be erased with the Duo Dkin algorithm and the Skin Painter algorithm.