Object and Pose Mode
Display panel lets you customize the look of your bones taking the shape of another existing object.
Hides the selected bone.
When enabled, bone is displayed in wireframe mode regardless of the viewport drawing mode. Useful for non-obstructive custom bone chains.
Blender allows you to give to each bone of an armature a specific shape (in Object Mode and Pose Mode), using another object as "template". In order to be visible the Shapes checkbox has to be enabled (panel).
- Custom Shape
Object that defines the custom shape of the selected bone.
- Bone Size
Option not to use bones length, so that changes in Edit Mode don't resize the custom shape.
Avoids having multiple custom shapes at different sizes.
Bone that defines the display transform of this shape bone.
To assign a custom shape to a bone, you have to:
Switch to Pose Mode Ctrl-Tab.
Select the relevant bone by clicking on it with RMB.
Go to the Display panel Custom Shape field and select the 3D object previously created in the scene; in this example we are using a cube and a cone. You can optionally set the At field to another bone.
These shapes will never be rendered, like any bone, they are only visible in 3D Views.
Even if any type of object seems to be accepted by the Object field (meshes, curves, even metas...), only meshes really work. All other types just make the bone invisible; nothing is drawn...
The center of the shape object will be at the root of the bone (see the bone page for root/tip).
The object properties of the shape are ignored (i.e. if you make a parallelepiped out of a cube by modifying its dimensions in Object Mode, you will still have a cube-shaped bone...).
The "along bone" axis is the Y one, and the shape object is always scaled so that one Blender Unit stretches along the whole bone length.
If you need to remove the custom shape of the bone, just right-click in the Custom Shape field and select Reset to default value in the pop-up menu.
So to summarize all this, you should use meshes as shape objects, with their center at their lower -Y end, and an overall Y length of 1.0 BU.