The Weight hammer tool lets you quickly fix vertices with weights that are causing spiky or otherwise undesirable deformation. Clicking the Weight hammer assigns selected vertices with weight values from neighboring vertices.

To fix vertices with undesirable weights

1. Open the Paint Skin Weights Tool (Skin > Edit Smooth Skin > Paint Skin Weights > ).
2. In the Paint Weights section, switch to Select or Paint Select mode.
3. Select the vertices you want to fix.
4. Click the Weight hammer icon.

   The selected vertices are assigned the same weight values as their neighboring vertices. When you exercise the skeleton, you see smoother deformation results.