Simple Addon for blender, for setting your vertex alpha channel in specific tones
Install like any addon, -> Preferences -> Addons -> Install
(You only need the .py)
1.Travel to the Viewport
2.Select the vertices you want to change
3.Select the Tool, Toolbar
4.Use the slider to set a value
5.Press "Set Vertex Alpha"
Profit
Remember that you need to set up a shader beforehand to visualize the alpha channel in blender, it's commonly used the Color Attribute Node