How to attach an object to your avatar

Build an object on the ground, here a cowboy hat.
Center it well ! (see chapter Add Volumes)
Click on the object, menu Object > Take Copy, to take it in the inventory.

In the inventory, click on the line of the object, Wear menu, to wear it on the avatar.

In the inventory, click on the line of the object, menu Properties.

In the Properties window, choose:
Mesh: the mesh number of the object to be attached (all meshes of the object must be attached)
Bone: the name of the avatar's bone on which you want to attach the mesh
X, Y, Z : mesh displacement relative to bone
Rot X, Y, Z : mesh rotation relative to bone
Heel: in case of female avatar shoes, choose the type and the height of heel

Click Apply to test the setting, OK to close

How to Attach an object on your screen ?

By choosing the Bone HUD_FULL_SCREEN, you can attach an object on your screen (actually on your camera).
You will be the only one to see it.

This can be used to create clickable icons on your Planet window (place a script in the object to perform an action), or to create hoods or dark glasses to hide the world.

The HUD_HORIZONTAL_FIT and HUD_VERTICAL_FIT Bones are identical, except that when you change the proportions of your Planet window, they are stretched differently. Note that not everyone has the same screen resolution so choose a Bone that is suitable for the purpose.