From 3D-Coat Wiki
There are only a small number of commands in the sidebar, but they are all very important. Let’s go over them.
double the amount of voxels the current object layer has. This allows for a layer to have much more detail at higher resolutions. You can view the resolution of a layer, in the VoxTree, directly before the layer’s name. If it has just the name then you will know that it is at it’s base resolution and has not been increased.
Clear. Will clear the current layer in the VoxTree of any voxels. Thiss useful for when you wish to keep the current layer’s name and resolution, but not the voxels. Smooth. Will uniformly smooth (or relax) all of the voxels of the currently selected object layer in the VoxTree.
Commands demo video