There are many functions in the right click menu inside of the VoxTree. Some of them are unique to this menu, most however, are not.
Much of the power of voxels is found in the functions contained in the Vox Layer, “Right-Click” menu set.

Perform Layer Merging, create Boolean associations, clean up scanned mesh data, make “shell” structures, create radial symmetry arrays, adjust and resample voxel resolution - all these things, and more, can be done with this set of functions.

They are as follows:

Show All Hidden Volumes: Show All Hidden Volumes.
Show Hidden Volumens in SubTree: Show Hidden Volumens in SubTree.

Delete: Deletes the selected Layer.
Add Child: This is the same as clicking the “+” icon near the Layer’s name. It adds a Layer that is a child of the current Layer.
Rename: Type your own name for the Layer, instead of the default “Volume XXX”.

Decrease object 2X: Increases the selected object Layer’s density twice. Object will decrease twice.
Increase object 2X: Decreases the selected object Layer’s density twice. Object will increase twice.
To global space: Moves the object to 0 on all axes. This is great when you need to move something directly into the center of world space to allow for a more perfectly symmetrical object when symmetry is active.
To uniform space: Applies orthogonal symmetry across the designated symmetry axis.
Resample: Duplicates the same command present in the Surface Tools.
Radial Array: Applies all settings you have made while using the “Radial” tool, with any number of slice counts to the array. The geometry will remain in the same SculptTree object it was originally in. The geometry can also be created as instances to their own objects in the SculptTree, instead of the original by turning on “Instance” in the Tool Options panel. Let’s look at the tool options:

• To X/Y/Z: Aligns the Rod Transform gizmo to the specified axis.
  
• Begin/End: Allows you to specify the exact coordinates numerically of the beginning and end of the Rod Transform gizmo.
  
• Gizmo Length: Numerically specify the length of the Rod Transform gizmo.
  
• Screen Based: Sets the size of the gizmo to be relative to the viewport.
  
• Array Count: The number of radial slices of the array.
  
• Instance: Create instanced VoxTree objects instead of duplicating the geometry to the same object.
  

Extrude: Extrudes all objects in the current layer outwardly by a specified amount. Enter this amount in the

• Extrusion parameter Dialog“ .
  

Extract Shell: Erase all internal volume of the object so that only a shell will remain. Makes a hollow skin based on a solid voxel sculpture.
There are 2 versions of this function:

• Make shell using voxels: Make a shell mesh using the voxel algorithm. It takes more time to calculate but works well for complex topology.
  
• Thicken Using Surface: Thicken the mesh object using surface extrusion. It is fast but can cause artifacts on complex topology.
  

Fill voids: Makes any voxel object a contiguous solid, which is necessary for creating proper topology either automatically or manually. This tool fills inner voids or hollows in the model.
Close Invisible Hulls: Close invisible hulls inside the object. Even if hull is not completely closed it may be closed by this tool because only small outer part of the hull is visible.

Thicken: (Surface mode only) Thickens the surface. Colors will be preserved.\ Close Holes in Surface: (Surface mode only) Close holes in mesh.
Object-ify (Separate Disconnected Pieces): (Surface mode only) Creates an object in the VoxTree for each separated piece of geometry, and places the geometry into those objects.

Save volume to 3B: Saves the voxel volume without its subtree to the 3D-Coat native file format.
Save volume with subtree as 3B: Saves the voxel volume with its subtree to the 3D-Coat native file format.
Import 3D File: import an external .3B file into the scene.
Edit shader settings: Edit custom shader’s parameters, if it has them. Opens the shader editing dialog for the current layer.
Import: Imports objects to Scene.

• Import Point Cloud: Import a set of points as a sequence of a small spheres.
  
• Import object: Import a standard 3D object into the scene.
  

Export:

• Export scene: Exports the whole scene as a set of separate objects.
  
• Export Selected: Exports the selected object.
  
• Save to Meshes Panel: Export current object to be used as a preset in the Meshes panel. A Preview of the current Layer object will appear in the “Models” Panel.
  
• Save to Splines Panel: Export current object as a profile for Spline panel.
  

This revised and improved Automatic Topology Creation function now produces very accurate, contour following topology automatically, that works equally well for both organic and mechanical shapes.
Auto Retopo

Retopo via decimation:
Transform: Transforms a whole object using a special gizmo.
Snap to Ground: Snap object to ground (zero). Only vertical parallel motion will be used.
Snap to Ground: Snap object to ground. Object will be moved and rotated to get physically stable position on the ground.
Lay On Ground: Lay object on ground. Object will be moved and rotated to get physically stable position on the ground.
Clone: Clones and transforms a sculpt object.

• Clone instance: Clones and transforms an instance of an object.
  
• Clone with symmetry: Clones with symmetry and transforms.
  
• Clone and degrade: Clones the layer and decreases the level of detail by 2 times.
  
• Clone space density: Creates a clone layer with the same density as that being cloned, essential for using the “Copy” tool.
  

Flip: Flips the current layer on any axis (X, Y, or Z). Flip Normals.

Bake color from Visibles Volumes: Bakes all vertex colors applied in Paint Room (Direct Painting) from all visible volumes to the current layer. This leaves the layer in Surface Mode.

Merge Visible (no booleans): This will merge all objects in the VoxTree that are not hidden to the current layer, leaving all visible layers intact.
Merge subtree (no booleans): Merges all sub-layers to the parent layer, deleting the sub-layers in the process.

Pick Icon: Instead of selecting destination layer from the list you may click there and pick layer directly from the viewport. The new RMB (right-mouse-button click) Layer Options greatly helps facilitate “pick and click” Boolean type Operations among others.

Copy & Merge With… (no booleans): Merge copy of the object to other object. Use SHIFT+LMB in VoxTree.
Merge with (Move to) (no booleans): Move object to other object space. You may use Drag&drop. Drop over [+] icon to move object to Sub-Tree. Alt + drag will duplicate object.

Soft Booleans settings: For booleans interaction. Works only in Surface Mode.

• Apply Soft booleans: switch this command on to use it.
  
• Soft Bevel Radius: Amount of Bevel.
  
• Bevel Shape: Selection for Flat Bevel (Bisel) or Rounded Edge.
  
• Bevel Division Counts: Use it if need more details.
  
• Addition relaxation within the bevel.
  

Merge Visible: Merge all visible layer to this one.
Merge Sub-Tree: Merge the Sub-Tree of this volume. All child layers will be deleted.
Copy & Merge With…: Merge copy of the object to other object. Use SHIFT+LMB in VoxTree.
Merge with (Move to): Move object to other object space. You may use Drag&drop. Drop over [+] icon to move object to Sub-Tree. Alt + drag will duplicate object.
Subtract from…: Subtracts an object in the current Layer from the object in another layer that you select. This is a very powerful function in 3dcoat: it allows boolean subtractions of one object Layer from another. Use CTRL+LMB drag & drop in VoxTree. Move object to other object space. You may use Drag&drop. Drop over [+] icon to move object to Sub-Tree. Alt + drag will duplicate object.
Intersect with: Adds an object in the current layer from the object in another layer that you select. This is similar to “Subtract from”, but allows boolean additions. Intersect volume with other one. Use CTRL+SHIFT+LMB drag & drop in VoxTree.
Remove intersection with: Remove intersection.
Split with: Split volume in two parts (volumes) with destination volume. Use SHIFT+ALT+LMB drag & drop in VoxTree.
Change parent: Changes the current Layer to another Layer or to the Root.

RMB Layer Options & Auto-Pick: This video covers the new RMB (right-mouse-button click) Layer Options that greatly helps facilitate “pick and click” Boolean type Operations among others. It also highlights the relatively new Auto-Pick option.

Voxeltree merging and subtracting This old video describes voxeltree merging and subtracting: Merging in volumes, Subtracting volumes, Transforming individual volumes, Voxtree functions.