brSmoothWeights for Maya

brSmoothWeights is a plug-in for Autodesk Maya to make skin cluster smoothing fast and easy making it one of the most used tools for skin weight smoothing.

It is production proven and used by many artists to get the skinning task done faster and more efficiently.

Features

• Adusting the size and strength reflects the behaviour of the default Maya sculpt tools.
• The tool is now multi-threaded and with large speed improvements.
• A selection mode streamlines fast vertex selection without having to switch tools. Use this to constrain the smoothing to a certain area or to keep the vertices from being smoothed.
• Use the smoothing depth option to smooth the front and back side of the mesh without having to rotate the model. The smoothing can even be applied to posed meshes with overlapping geometry.
• Smoothing crosses shell boundaries to maintain the integrity of the mesh when deformed. This feature takes away a bit of the overall smoothing performance but shouldn’t be noticable with regular meshes. If you are working with high resolution single-shell meshes it’s still possible to disable this option to improve the speed.
• The volume-based smoothing allows to smooth across several discontinuous shells whereas the default smoothing is surface based. Volume smoothing should be handled with care as it can easily introduce weights in areas which shouldn’t be affected.
• Customizable brush display and help information.

brTransferWeights is a complementary tool for skin weight editing which allows to easily transfer skin cluster weights from one influence to another either by painting or by setting absolute weights. The direction of the transfer can also be quickly reversed. By default the weights from the source influence are added to the destination influence but can also completely replace the previous values.

Watch the Full Overview Video

Compatibility

Linux 64 bit
OS X
Windows 64 bit

Maya 2020, 2022, 2023, 2024, 2025

Version

1.2.0

Installation

All files of the toolset are combined as a module. This allows for an easy installation and keeps all necessary files in one location.

To install unzip the download and drag the provided dragDropInstaller.py in the main Maya window. Depending on the type of chosen installation all files will be created and placed automatically. Also, a log file will be created documenting the installation.

Make sure you unzip before dragging the installer into the Maya window.

If you need help during the installation see the included installation guide which can also be opened from the installer window.

It's recommended to use the default installation path. Only use a custom path if you know how modules are handled in Maya.

After the installation restart Maya. The Skin menu in the rigging menu bar should now contain the menu items Paint Smooth Weights Tool and Paint Transfer Weights Tool.

Important Note

In some cases it's possible that the script generating the menu items isn't processed upon Maya startup. This leads to the menu items missing. In this case run the MEL command

brSmoothWeightsCreateMenuItems

You can also use this command to create a shelf button.

Usage

When properly installed the skin menu in the main Maya rigging menu bar contains the new menu items named Paint Smooth Weights Tool and Paint Transfer Weights Tool.

Select the mesh and activate the tool. LMB-drag on the mesh to smooth the skin cluster weights. The mesh needs to be selected when activating the tool.

For the brTransferWeights tool open the tool settings and select a source and destination influence by multi-selecting the items in the influence list. The direction of the transfer can be set with the button between the two influence fields (arrow indicating the direction).

Note

The brush circle only displays when the mouse button is pressed. This is due to a missing Qt implementation and still needs to be addressed.

• Brush size: MMB-drag the mouse left or right to adjust the size of the brush.
• Brush strength: MMB-drag the mouse up or down to adjust the strength of the brush.
• Select vertices: Shift-drag to select vertices to limit the area of the smoothing effect.
• Deselect vertices: Ctrl-drag to deselect vertices from the current selection.
• Clear the vertex selection: Shift+Ctrl+LMB“ to clear the current vertex selection.

Settings

• Size: The size of the brush in world units.
• Strength: The strength of the smoothing effect. A value of 1 defines a full averaging with neighbouring weights.
• Affect Selected: Smoothes only the selected vertices. When off only unselected vertices are affected.
• Oversampling: The number of iterations for the smoothing.
• Fraction Oversampling: When smoothing with oversampling the strength value is divided by the number of samples.
• Flood: Applies the smoothing to the current selection with the strength value. When only the mesh is selected the entire mesh will be considered.
• Depth Start: Define at which depth the brush starts to smooth vertices when painting. The default value of 1 means that the foremost visible surface of the mesh is affected. If only the backside of the mesh should be considered in a non-overlapping mesh this value should be set to 2.
• Depth: Sets how many overlapping mesh layers are considered for smoothing. If the front and back side of the mesh should be affected with the same brush stroke set this value to 2. If the back side has overlapping geometry because of a posed mesh (i.e. the arm crease opposite of the elbow) a depth of 3 or more might be required. Please note that the larger the depth the more vertices are evaluated. This might affect performance.
• Keep Shells Together: Extends the smoothing or selection across a shell boundary by trying to find an equivalent vertex on a neighbouring shell boundary in surface mode. This can help maintain mesh continuity during the deformation.
• Tolerance: The maximum distance to find an equivalent vertex on a neighbouring shell boundary in surface mode.
• Volume: Enables the volume mode where weights are smoothed based on the vertex distance. Since it’s volume based the weights can also spread across shells and nearby surfaces. When off the weights are smoothed based on the connected neighbours in surface mode.
• Range: The fraction of the brush size in which neighbouring vertices are considered for smoothing for each vertex in volume mode.
• Draw Brush: Displays the brush circle while smoothing.
• Brush Color: Sets the brush circle color.
• Line Width: Sets the line width of the brush circle.

brSmoothWeights and brTransferWeights are under the terms of the MIT License