How to Extrude a Bone from a Joint in Blender

Extruding a new bone from an existing joint in Blender is a fundamental technique used during armature creation and rigging. This article provides a straightforward, step-by-step guide on how to enter Edit Mode, select a specific joint or tip of a bone, and use Blender's extrusion tools to extend your skeleton structure efficiently.

Steps to Extrude a Bone

1. Select the Armature: Left-click on your armature object in Object Mode to select it.
2. Switch to Edit Mode: Press Tab on your keyboard, or select Edit Mode from the interaction mode dropdown menu in the top-left corner of the Viewport.
3. Select the Joint: Left-click directly on the specific bone joint (the sphere at the end or start of a bone) from which you want the new bone to extend.
4. Extrude the Bone: Press E to activate the Extrude tool.
5. Position the New Bone: Move your mouse cursor to extend the new bone to your desired location.
6. Confirm Placement: Left-click to finalize the position of the new bone.

Precision Extrusion Techniques

• Constrain to an Axis: After pressing E, press X, Y, or Z to lock the extrusion along a specific global axis. Pressing the axis key twice locks it along the local axis.
• Exact Length: Press E, choose an axis (e.g., Z), and type a numerical value (e.g., 2) to extrude the bone by an exact distance, then press Enter.
• Symmetrical Extrusion: Enable X-Axis Mirror in the Tool Settings tab of the Sidebar (press N) to extrude identical bones on both sides of a symmetrical model simultaneously.