How Do You Turn a Mask into a Polygroup in ZBrush?

To turn a mask into a Polygroup in ZBrush, simply create the mask and then press Ctrl+W. This action converts the masked area into a new Polygroup. Here's a more detailed breakdown:

Method 1: Using Masking and Ctrl+W

This is the most direct and common method:

1. Create Your Mask: In ZBrush, use any of the masking tools (e.g., Ctrl + Brush, Lasso Mask, etc.) to define the area you want to turn into a Polygroup. The masked area will appear darker.
2. Convert to Polygroup: With the desired area masked, press Ctrl+W (Windows) or Cmd+W (Mac). This command will create a new Polygroup encompassing the masked region. The newly created Polygroup will usually have a different color than the surrounding geometry, making it easy to identify.

Method 2: Hiding and Grouping Visible

Another method involves hiding geometry and then grouping what remains visible:

1. Hide Parts of the Model: Use the selection brushes (Ctrl+Shift + Brush) to hide the parts of the model that you don't want in the new Polygroup.
2. Group Visible: Go to the Tool > PolyGroups sub-palette and click the "Group Visible" button. This will create a Polygroup from the visible (unhidden) parts of your model.

Key Considerations:

• Mask Clarity: Ensure your mask is clean and well-defined to avoid unwanted Polygroup boundaries. Use masking brushes with sharp alphas for precise masking.
• Visibility: When using the "Group Visible" method, make absolutely certain that only the intended geometry is visible. Accidental visibility of unwanted parts will lead to those parts being included in the Polygroup.
• Polygroup Colors: ZBrush automatically assigns random colors to new PolyGroups. You can manually change the color of a PolyGroup by activating Colorize in the Tool > Display Properties sub-palette and then painting the desired color onto the selected PolyGroup.
• Alternative Method: You can also use the "PolygroupIt" plugin for creating Polygroups, which offers advanced features for automatic polygrouping based on angles and other parameters.

In summary, creating a Polygroup from a mask in ZBrush is primarily done by masking the desired area and then pressing Ctrl+W. Alternatively, you can hide parts of the model using selection brushes and then use the "Group Visible" function.